Methods for drying foliate underground geological formations

FIELD: technology for increasing recovery of hydrocarbons from foliate geological formations, which contain absorbed condensed gaseous hydrocarbons, by processing such geological formations with dehydrating compositions, containing surfactants, which cause dampening of geological formation with oil or leave aforementioned formations dampened with oil.

SUBSTANCE: methods may be used for excitation of influx of fluid substance from geological formation into well, or hydro-acid fracture, or hydraulic fracture, during maintenance or major repairs and when increasing influx from natural cracks or from geological formations never subjected to influx stimulation.

EFFECT: increased water removal efficiency, minimization of migration of low dispersion particles, increased extraction of hydrocarbons from underground formations, containing absorbed and compressed gaseous hydrocarbons.

3 cl, 4 ex, 6 tbl

 

The scope of the invention

The present invention relates to the production of hydrocarbons, in particular to methods of increasing gas production from schist geological formations having a high saturation with water, and more specifically to the reduction of the saturation of water in geological formations, the immediate area surrounding either the wellbore or surface cracks by processing of geological formations using surfactants having good wetting characteristics of the oil in the presence of shale. Reducing the saturation of water increases the flow of hydrocarbons in these geological formations. These methods can be used in drilling, completion, stimulation of the flow of fluid from the geological formations in the borehole (acidification, or hydrocyclones gap, or hydraulic fracturing), repair or overhaul, and to increase the flow of natural cracks or geological formations is not exposed to the excitation of the flow.

Background of the invention

The present invention relates in General to the production of hydrocarbons (oil and natural gas from wells that drill into the earth. Hydrocarbons produced from underground geological formations (i.e., "reservoir") by drilling a well bore that penetrates through the geologic formation containing ug is avodarte. In order to obtain hydrocarbons, that is, passing from the geological formation to the wellbore and, ultimately, to the surface at flow rates sufficient for economically viable production must exist or be provided essentially unimpeded path from an underground geological formation to the wellbore and then to the surface. Of course, it is desirable to maximize both the flow rate and total flow of hydrocarbons from an underground geological formation to the surface, where they can be extracted.

The production of hydrocarbons, usually limited to two main factors of tank: porosity and permeability. Even if the porosity is adequate, effective permeability to hydrocarbons may be limited. When the permeable system contains more than one fluid, the flow of each of them depends on the number and distribution of all others; in particular, the relative flows depend on which fluid medium is a "wetting" phase, that is the fluid that covers a surface. Depending on many factors one fluid medium can flow, while the other isn't. The result is stagnation of fluid in the geological formation naturally pony who moved the recovery rates of hydrocarbons. There are both simple and complex causes. In the simplest case, the presence of a fluid medium, in particular water or saturated salt solution, in the geological formation acts as a barrier for migration of hydrocarbons from geological formations in the wellbore. More precisely, fluid water-based injection during the treatment of wells, can fill the space of the pores in the treated area, preventing migration of hydrocarbons in the same space then, or through them. Similarly, if the well should be developed without initial excitation flow naturally present in geological formations on the path of leakage or potential leakage of fluids water-based can be difficult prey.

Indeed, the decrease in effective permeability caused by stagnant fluid environments, often restricts the extent of hydrocarbon production (both speed and performance from this well. In order to increase the productivity of wells must therefore remove stagnant fluid from the geological formation. There is not a satisfactory way to remove these fluid and thereby prevent lowering of production because of their presence.

In their natural state geological formats and can be wetted by the oil, wetted with water or have a mixed wettability depending on the nature of the fluid and geological formations. (In this and subsequent discussions, the term "wet oil" is seen as covering the surface, which are also adsorbed, condensed or compressed gas). When the inner surface of the oil - or gas-bearing geological formation or pore, formed by the surface crack is wetted by the oil phase will occupy the surface of the pores, and also the smallest barely permeable pathways. As such oil or gas will flow through a restricted path for their production, and water, which is nonwetting, will be able to flow through the least restricted flow path with high permeability. For this reason, to reach maximum capacity for the flow of oil or gas, as a rule, it is preferable that the surface of the pores was specialas water.

The only exception to this recommendation is a specific case of the extraction of methane from coal seams. In these types of geological formations most of the gas in coal is adsorbed at a very high area of the inner surface wetted by oil organic constituents of the coal, and, as a consequence, the coals are described as is iesa, as a rule, wetted with oil in contrast to conventional gas reservoirs, which are composed of inorganic minerals, which, as a rule, are wetted with water. In U.S. patent No. 5229017 Nimerick et al. they say that the processing of coal geological formations with dehydrating substances to create a stable oil-wetted surfaces of the coal increases gas production by reducing the tendency of fine formations geological formations to migration and increased drainage of water from the geological formation. More specifically, Nimerick et al. describe the use of some organic surfactants selected from derivatives of butyleneglycol or polietileniminov for hydraulic fracturing.

However, Nimerick et al. do not say anything about other normal operations associated with the tank, such as drilling, completion, repair, acidification, hydrocyclones the gap or increase the flow in natural fractures, they also do not mention treatments conventional gas reservoirs, which, as a rule, are wetted with water or should be wetted with water, or where produced hydrocarbons are porous mineral matrix, such as shale geological formations similar to the Devonian shale and Barnett shale. For these conventional geological form of the s General order still is what wetted surface water are preferred.

It is observed that, when the geological formation is a shale, which has a high content of water, hydrocarbon production, particularly if they are located in geological formations mainly in the form of adsorbed condensed gas can be stretched over time and slow. The problem usually occurs in gas wells, such as wells in shale geological formations that contain high concentrations of adsorbed gas, particularly natural gas (which the authors will be mentioned as "methane" in the following discussions) as opposed to those that contain primarily compressed, but neadsorbirovanne gas. For such wells, the most important is to remove water as quickly and fully as possible, in order to maximize the rate of production and total methane production. Thus, the operator can apply the maximum pressure drop in the geological formation, but not in the wellbore. Water inside the geological formation accelerates desorption and gas flow.

For those schist geological formations that contain adsorbed gaseous hydrocarbons, the authors found that would be acceptable to the geological formation was not wetted the TEW during gas production, because it allows for faster and more complete removal of water and to open a larger number of pores for gas flow. Is also the advantage of minimizing the migration of fine particles as the fine particles block in the system of production pathways from the geological formation to the downhole equipment and surface equipment. In General, the same factors and arguments with appropriate modification of specific situations related to the initiation of the flow of fluid from the geological formations in the borehole (acidification, or hydrocollator rupture, or hydraulic fracturing), repairs or overhaul, and to increase the flow of natural cracks or geological formations is not exposed to the excitation of the flow.

Brief description of the invention

There are many operations associated with oil and gas wells in which geological formations are wetted by oil or be wetted by the oil, and the presence of significant quantities of water in the pores or cracks is harmful. The common denominator of the ways covered by the present invention, is that they all deal with the increase in the production of hydrocarbons from underground geological formations that contain adsorbiroval the data and compressed gaseous hydrocarbons, in particular methane, in the matrix-rich schists, and that this increase is achieved by such effects on the geologic formation that becomes or remains wetted by the oil, thus contributing drainage slate and maximizing the number of flow paths for hydrocarbons. Under "impact on the geological formation that becomes or remains wetted by the oil, the authors imply that if the geological formation was wetted with water, it becomes wetted by the oil and continues to be wetted by oil, although quite a large amount of water or saturated salt solution flows through the geological formation and is removed from it to obtain the results required from this method of processing, and if the geological formation was wetted by the oil, it continues to be wetted by oil, although quite a large amount of water or saturated salt solution flows through the geological formation and is removed from it to get results required from this method of processing. Under "adsorbed and compressed gas, the authors imply that the geological formation contains adsorbed gas on the surface and additional gas contained in the pores of geologic formation, in a compressed state.

The authors found that concrete is e types of dehydrating substances, leave a lasting wetted by the oil surface, significantly increase the drainage of oil shale, accelerate gas production and increase the total amount of the produced gas. In particular, these substances contain:

(a) organic surface-active compounds having the formula R1-(EOx-PrOy-BuOz)H, where R1 is an alcohol, phenol or a derivative of phenol or fatty acid having from 1 to 16 carbon atoms, EO represents ethyleneoxide group, and x is from 1 to 20, PrO represents propylenoxide group, and y is from 0 to 15, and BuO is butyleneglycol group, and z is equal to from 1 to 15;

(b) organic polietilensorbit having the formula

R2 is-(-CH2-CH2-O-C(O)-O-)qH

where R2 is an alcohol having from 7 to 16 carbon atoms, and q is from 7 to 16;

(c) butoxysilane glycols having from 1 to 15 butylaniline groups;

(d) ethoxylated-butoxysilane glycols having from 1 to 5 ethyleneoxide groups and from 5 to 10 butylaniline groups; and

(e) alkyl-aminocarbonyl acids or carboxylates.

These dehydrating agents have good characteristics associated with wettability in oil. The ability to lower the saturation water containing gas shales will increase the relative permeability to gas in geological formations. This increased permeability to gas b the children to improve well productivity and significantly improve economic characteristics of the processing oil fields, use fluids that contain these dehydrating agents. Strong adsorption drying substances on the surface of the slate supports the state of wettability in oil, thus contributing to the lowering of the saturation of water in the shale. Surface-active substances which give rise to surface geological formations, wetted with water, will not be fit for use.

One of the embodiments of the invention is a method for draining schist containing hydrocarbons underground geological formation that contains adsorbed and compressed gas, comprising a stage of bringing into contact with the geological formation with an effective amount of fluid for treatment of wells containing one or more dehydrating substances, under the action of which the geological formation becomes and remains wetted by the oil; and removing water from the geological formation.

Another embodiment is a method to increase gas production from schist containing hydrocarbons underground geological formation that contains adsorbed and compressed gas, comprising a stage of bringing into contact with the geological formation with an effective amount of fluid for treatment of wells containing one or more dehydrating substances which, under the action of which the geological formation becomes and remains wetted by the oil, remove the water from the geological formation and removal of gas from geological formations.

Another embodiment of the present invention is a method of hydraulic fracturing of slate underground geological formations containing high concentrations of adsorbed and compressed gas. This method includes a step of injection of the composition of the fluid for the well treatment according to the present invention through the wellbore in a geological formation at a flow rate and pressure sufficient to create or extend fractures in the geological formation. Fluid for the well treatment contains one or more surfactants that create or maintain wetted by the oil surface. Dehydrating substances are particularly effective in promoting recovery of the pumped fluid for fracturing of geological formations near the surface of the crack, where it was pumped into the pores during processing for hydraulic fracturing. In addition, water containing surfactant may also contain a wide range of functional additives, for which it is known that they improve performance processing for fracturing Such functional additives include polymers, compounds for cross-linking, grinding agents, biocides, scale inhibitors, proppants, etc..

Other embodiments of the present invention provide for processing with the purpose of repairs or overhaul gas wells in slate underground geological formations containing high concentrations of adsorbed and compressed gas, to increase their drainage and gas production. These methods include stage discharge into the well, which was productive for some time and could or could not be subjected to excitation inflow (rupture and/or acidification) in the past, and may contain natural fissures, composition of the fluid for the well treatment according to the present invention and through the wellbore in a geological formation at a flow rate and pressure less than the burst pressure.

Other embodiments include acidification and hydrocyclones gap schist underground formations containing high concentrations of adsorbed and compressed gas, then there are ways, as described above, in which the pressurized fluid medium promotes drainage and, in addition, contains acid and is pumped under pressure either higher or lower than the burst pressure in geological formations.

Another embodiment is a fluid environment to drill the treatment or completion, containing one or more of the drying substances for shale described above.

These and other embodiments can use foam or energizerbunny fluids, if the selected surfactants known as forming a stable foam or if fluids additionally contain foaming additives, and selected surfactants are not protivoprilipajushchie.

Other embodiments will be clear to experts in the field of underground mining fluid.

Detailed description of the invention

In accordance with the present invention fluid medium for water-based well treatment is used in the treatment of wells in schist geological formations containing adsorbed and compressed gaseous hydrocarbons. The term "well treatment" authors include drilling, completion, repair, initiation of flow of fluid from the geological formations in the borehole (acidification or hydrocyclones gap, or hydraulic fracturing) and increase the flow of natural fractures or in geological formations is not exposed to the excitation of the flow. Any of these types of well treatment, excluding, of course, drilling and part of the completion associated with drilling, can be repeated, if desired or necessary, usually in the process control operation of the well or reservoir. Various processing oil fields often must be repeated due to changes in structures or in flow rates, often, in turn caused by changes in temperature or pressure or associated with the deposition of scale, paraffins, asphaltenes and the like. Treatment according to the present invention may include performing such initial processing in the borehole or geological formations or subsequent processing (in this case, the initial treatment can be performed or not performed in accordance with the methods of the present invention). Fluid medium includes a dehydrating substance to facilitate the removal of water from geological formations, cracks or zakislenna surface, if such exist, and the field of geological formation in the vicinity of cracks, zakislenna area or wellbore.

In the following discussion under the "slate" the authors imply compacted sedimentary geological formation in which its constituent mineral particles mainly represent a very fine clay, silt or mud, but it can contain small amounts of other materials, such as Sandstone, carbonates or kerogen. Under the "slate" the authors mean the geological formations in which the mineral content is more than comprimere 40% clay or shale, in contrast to Sandstone or carbonate. Under the "coal" the authors mean a combustible rock composed primarily of plant material, compressed and modified under the influence of time, temperature and pressure, the organic material having a high carbon content; coal may contain a number of slate or other minerals. Under "water," the authors mean the fluid is water-based, which may contain organic or inorganic source or added solid, liquid or gaseous materials which are dissolved or suspended in it, such as salts, carbon dioxide, nitrogen, alcohols, mixed with water, oil components, and the like. More specifically, under water the authors include water or saturated salt solution, or fluid environment for processing borehole water-based.

Processing of slate tanks that contain significant concentrations of adsorbed gas, requires technologies that are quite different from those used in conventional reservoirs Sandstone or carbonate. How well treatments are applicable to the geological formations in which from about 1% to about 100% gaseous hydrocarbons are adsorbed gaseous hydrocarbons (in particular methane), concrete is, from about 5% to about 100%, and most specifically from about 20% to about 100%. As pressure reduction in the geological formation at a certain pressure, namely the critical pressure of methane desorption determined by the desorption isotherm Langmuir, methane will begin to decarbonate of geological formations. In addition, these geological formations are often significantly or completely saturated with water. In these cases, must be removed large quantities of water to lower the pressure in the tank to a point lower than the critical pressure of methane desorption. For this reason, the well treatment carried out in such geological formations, should be designed to effectively extract water. Maintaining shale in the state, wetted with oil, facilitates the extraction of water.

Typically, as discussed above, experts in the field of hydrocarbon production from conventional (as opposed to coal) underground geological formations, it is assumed that the most preferred is the maintenance of geological formations in the conditions of wetting by water. References discussing the impact of wettability geological formations in oil production include: Anderson, William G., Wettability Literature Survey - Part 5: The Effects of Wettability on Relative Permeability, " Journal of Petroleum Technology 1453-1468 (November, 1987); Anderson, William G., Wettability Literature Survey - Part 6: Te Effects of Wettability on Waterflooding. Journal of Petroleum Technology, 1605-1621 (December, 1987); McLeod Jr., Harry O., Matrix Acidizing. Journal of Petroleum Technology, 2055-2069 (December, 1984); and Ribe, K.H., Production Behavior of a Water-Blocked Oil Well. SPE 1295-G (1959).

In addition, the following link talks about how to ensure that geological formations were wetted with water: Gidley, J.L., Stimulation of Sandstone Formation with the Acid-Mutual Solvent Method, Journal of Petroleum Technology, 551-558 (May, 1971). The following links describe the impact of wettability in geological formations, which produce gas: Holditch, S.A., Factors Affecting Water Blocking and Gas Flow from Hydraulically Fractured Gas Wells, Journal of Petroleum Technology, 1515-1524 (December, 1979); and Baker, B.D. and Wilson, J.C., Stimulation Practices Using Alcoholic Acidizing and Fracturing Fluids for Gas reservoirs, SPE Paper 4836, presented at the SPE European Spring Meeting held in Amsterdam, The Netherlands, May 29-30 (1974).

However, the authors found that under certain circumstances it is preferable to maintain the geological formations in the state of wetting by oil.

In accordance with the present invention the drying substance is an organic surfactant selected from the group consisting of:

(a) compounds of organic surfactants having the formula R1-(EOx-PrOy-BuOz)H, where R1 is an alcohol, phenol or phenol derivative or a fatty acid having 1 to 16 carbon atoms, EO represents ethyleneoxide group, x is from 1 to 20, PrO is a sawn through the sydnaya group, y is from 0 to 15 and BuO is butyleneglycol group, z is equal to from 1 to 15;

(b) organic polietilensorbit having the formula

R2 is-(-CH2-CH2-O-C(O)-O-)qH

where R2 is an alcohol having from 7 to 16 carbon atoms, and q is from 7 to 16;

(c) butoxycarbonyl glycols having from 1 to 15 butylaniline groups;

(d) ethoxylated-butoxycarbonyl glycols having from 1 to 5 ethyleneoxide groups and from 5 to 10 butylaniline groups; and

(e) alkyl-aminocarbonyl acids or carboxylates.

Where surfactants contain one or more ethoxy-, propoxy - and butoxysilane, the exact order of these links inside a molecule is not critical. As the group R can be obtained from a natural product, the group R may have a random distribution of carbon atoms. Surfactants suitable for use in the present invention include those described Nimerick et al. in U.S. patent No. 5229017 (owned by Schlumberger Technology Corporation). This patent, thus, is included here by reference in its entirety. The way to obtain organic polietileniminov be found in U.S. patent No. 4330481. This patent, thus, is included here by reference in its entirety. Surfactants in paragraphs (a) and (b) above describes ZV is camping with the structural formula, slightly different from those shown in U.S. patent No. 5229017.

Other surfactants suitable for use in the present invention, is described in application for U.S. patent No. 09/513,429, England et al. (registered 25 February 2000; owned by Schlumberger Technology Corporation), which describes several foaming agents for the release of methane from coal, which have functional properties similar to organic surfactants described in U.S. patent No. 5229017. This application describes methods that require surfactants that are effective for wetting by oil and foaming. Surfactants of this proposal, which provide wetting oil, and only those that provide wetting oil will be effective in the present invention, regardless of whether they provide foaming or not. In fact, one class of surfactants (alkyl-aminocarbonyl acids or carboxylates), which, as shown in this application are not applicable, are applicable in the present invention. Application for U.S. patent No. 09/513,429 included, thus here by reference in its entirety.

Particularly preferred examples are alcohols, substituted with ethylene oxide is butyleneglycol (such as butanol, with about 3 ethylenoxide link and about 5 butylaniline links); di-secondary butylphenol having about 5 ethylenoxide links and about 4 butylaniline link; decanol with about 10 efilecabinet links; a mixture of simple diethylene glycol-monobutyl ether, simple triethylene glycol-monobutyl ether and simple higher glycol ethers having about 4 ethylenoxide level and about 6 butylaniline links; tridecylamine alcohol having from about 7 to 8 ethylenoxide and approximately 3 to 4 butylaniline links; tridecylamine alcohol having about 7 ethyleneoxide units and about 1 to 2 butylaniline links; simple and triethylene glycol-monobutyl ether-formal, which has the formula

(BuO(-CH2-CH2O)3)2CH2.

Other usable surfactant includes alkyl-aminocarbonyl acid or carboxylate, more preferably alkyl-aminopropionic acid or propionate. In one of specific embodiments of the surfactant has the formula

R-NH-(CH2)n-C(O)OX

where R represents a saturated or unsaturated alkyl group having from about 6 to about 20 carbon atoms, n is 2-6, and X represents hydrogen or a cation forming a salt. In various specific embodiments of the infusion is his invention, n may be equal to 2-4, most preferably 3; and R may be a saturated or unsaturated alkyl group having from about 6 to about 20 carbon atoms. As the group R can be obtained from a natural product, the group R may have some distribution of the number of carbon atoms. One particularly preferred surface-active substances is Coco aminopropionic.

The drilling methods, the excitation of the flow of fluid from the geological formations in the borehole (acidity or hydrocollator gap, or hydraulic fracturing), repairs or overhaul and increase the flow from natural cracks or from geological formations that are not subjected to the excitation of the flow, well known to experts in the field of underground mining fluid. Drilling involves the rotation of the drill bit on the end of the drill string in the well with the simultaneous circulation of the fluid to be processed in the borehole (drilling mud). The drilling fluid functions to the removal of debris on the surface, for cooling and lubricating the drill bit and to control the flow of fluid from the wellbore in a geological formation or geological formations in the wellbore. Completion is a drilling productive geological formations and implementation of specific steps to complete about the ECCA drilling and allow for hydrocarbon production from the desired areas. Repairs and overhaul represent operations (such as recess, removing and re-installing the cladding and the like), carried out to increase production from wells. Acidification is a processing of geological formations with acid for the purpose of increasing production by etching rocks, removal of soluble, causing damage to the material and increasing the space of the pores and passages. Hydraulic fracturing will be described in detail below. If hydraulic fracturing is carried out using an acid fluid, it is referred to as hydrocyclones gap. Why and how to select all these ways and fluid for these methods, in particular in relation to their chemical and physical properties in relation to geological formations, known to experts in the field of underground mining fluid.

An effective amount of surface-active substances of the present invention can easily be determined by such persons without undue experimentation. These surfactants can be used in a wide range of concentrations, typically from 0.01 percent volume up to 10 percent of the volume, but preferably between 0.05 percent of the volume and 10 volume percent, and most preferably between 0.05% the NTA volume and 0.5 percent of the volume of the entire fluid for processing. (Note that 1 volume percent is equivalent to 10 gallons per thousand gallons (gpt)). Similarly, the choice of surfactant can be done using widely known methods by experts in the field of mining underground fluid when assessing the nature of the surfaces and fluid (as present initially, and injection), involved in the process, including taking into consideration the other chemicals present in the originally existing or injected fluids, and whether or not the fluid medium for processing to be foaming or energizerbunny or not. Surfactants can be mixed directly with fluids used in various treatments of all wells listed above, as these fluids are prepared in advance, or surfactants can first be prepared in the form of concentrates, in particular concentrates on a water basis, and then these concentrates are used in the preparation of the final fluid.

One example of a method of well treatment according to the present invention is a hydraulic fracturing an underground reservoir. Hydraulic fracturing is a common practice to increase the production of oil or gas from underground reservoirs. Applies to the number of design solutions processing depending on the specific characteristics of the geological formations, the quality of reserves and working environment. However, for all types of processing require the creation of new areas of surface flow and ensuring that there is good hydraulic conductivity and communication between the wellbore and the reservoir. Any damage produced by hydraulic fracturing and geologic formation surrounding the region of the gap, can reduce hydraulic conductivity and the message, thereby reducing the ability of the newly created surface inflow to allow passage of the desired quantities of oil and gas. The damage gap takes many forms, but is located either in the gap, either in a geological formation immediately surrounding the gap (surface cracks).

Breaks most often initiated using 1-4 gallons of selected drying surfactants in accordance with the present invention per 1000 gallons of water. Water can be a water pure or saturated salt solution, and may also contain small amounts of polymer (natural or synthetic) substances substances. This stage - cushion gap - has a high leakage of water (depending on the permeability and pressure difference) in geological formation and is primarily intended to initiate cracks or cracks, and for whom asemenea initial dewatering quantities of surface-active substances in geological formations. After the initiation of cracks inject additional fluid environment for fracturing, for a more extensive cracks; this fluid typically contains a higher loading of the polymer (up to 40-60 pounds per thousand gallons). The polymer may be either transversely crosslinked or not crosslinked.

Fluid for the well treatment according to the present invention can also be used for repair work, i.e. to increase production of water and gas from the "bad" fields, which were previously subjected to rupture and the effects of proppant, or wells that contain any conductive drainage channels to the wellbore. When this processing water with a small loading of the polymer or without uses for transportation from 2 to 4 gallons of selected drying surfactant per 1000 gallons of fluid in the geological formation. This processing is generally carried out at a pressure less than the burst pressure, in order to prevent leakage of proppant that can be present in the crack. The total volume of fluid containing the drying surface-active substance, must depend on the height of the geological formations and the desired penetration of the fluid to be processed, containing the drying surface-AK the active substance.

Surfactants of the present invention adsorbed on the surfaces, thereby increasing the hydrophobicity schist geological formations. Preferred surfactants are also relatively strongly associated with surfaces, thereby preventing re-wetting with water and re-adsorption of water on the surface during the passage of the subsequent volumes of water during the washing fluid for fracturing, drainage geological formations and processes of hydrocarbon production. Thus, all these benefits can be realized over a long period of production of hydrocarbons. This feature surfactants delivers the additional advantage that, since surfactants are strongly linked with the surface, only small their number, if any, contained in the extracted water, thereby greatly reducing any problems in the field of the environment associated with the release of the extracted water. In addition, the surfactants of the present invention inhibit the migration of fine particles within a geological formation, on the surface of the crack and the crack, thereby additionally increasing and maintaining the conductivity of the crack.

Of course, all surface-act the main substances have almost completely washed off from any surface under the action of a sufficiently large volume of water or saturated salt solution, does not contain surfactants. Satisfactory performance in the methods of the present invention is achieved if the surfactant remains on the surface long enough to achieve the desired results of a particular treatment. In particular, it should be noted that satisfactory performance, measured by how strongly surface-active substance is bound with the surface geological formations, must be different for surfactants, which are also foaming agents, in contrast to surface-active substances, which they are not. Fluids for processing sometimes foaming or analiziruyutsya using gases for various reasons, such as the achievement of some other more desired results (outcomes), for example, to facilitate hydrostatic loads during processing and after it, to use a smaller amount of a primary fluid, in order to produce less damage to geological formations or to produce less damage to the gaskets with propping agent or gravel packing, and the like. Without intending to be bound by any theory of the present invention, assume that the surface-active ve is the EU ETS according to the present invention, which are good foaming substances inherent in the less strong adsorption on the surfaces of geological formations than surface-active substances, which are natoaritime or protivoprilipajushchie substances. Thus, when using surface-active substances, it is known that they form a stable foam, a sufficiently large volume of water or saturated salt solution flowing through the geologic formation and extracted from it to produce the results desired from the processing method may be less than the amount that is acceptable when using surfactants, which does not form a foam. This effect can be eliminated, if desired, by using a higher concentration of surfactant in the processing methods or by repeating processing methods, whichever is more convenient.

The present invention can additionally be understood from the following laboratory experiments. The preferred surfactant of the present invention, namely A Surfactant product containing tridecylamine alcohol with a branched chain having about 7.5 ethylenoxide links and about 3.5 butylaniline links, which is commercially available from Schlumberger, the use is conducted to illustrate the effectiveness of the surfactants of the present invention, to minimize surface of the inputs in the cracks in schist geological formations.

Example 1

Carry out experiments to assess the performance of drainage and saturation of the Surfactant A in the Barnett shale. The concentration of A Surfactant used for the processing of oil shale, consists of 0.0 and 0.5, 2, and 4 gpt (gallons of additive per thousand gallons of fluid).

The following information is recorded during flow studies in the shale gaskets:

1) the Speed with which the water fills the column with crushed core material shown in table 1.

2) the Speed with which the water is drained from the column with crushed core material shown in table 2.

Experiments on drainage are meaningful in relation to the reduction of surface tension and drying ability of the fluid to be processed. The greater the amount of fluid that leaves the pipette, the better performance fluid for processing.

Procedure. The sample of oil shale is crushed and the fragments screened between sieves 30/100 mesh. Fragments stuff (calling it shale gasket) in the pipette and hold it vertically narrow pipette tip down. Mesh 100 mesh, stuffed in a sharp tip of a 5 ml pipette, prevents the leaching of elements from the pipette. Fluid to be processed, containing over OSTO-active substance, fresh water and 2% KCl, is blown into the upper part of the pipette using a 3-ml syringe. (The amount of shale in the 5-ml syringe is such that approximately 3 ml of fluid for processing filled his pores). Initially shale gasket is dry, so it is possible to track how fluid medium for processing saturates (table 1), and then goes from shale gaskets (table 2). Time set to zero after the boundary of the fluid processing was dropped to the surface of the shale gaskets (now fluid medium for processing saturates the gasket and ready to start to leak from gaskets, allowing for admission of air from the top). The distance at which air enters the gasket due to a leak of the fluid to be processed, recorded as a function of time.

Measurements carried out every 15 seconds for research "fill" (see table 1) up until shale gasket will not be filled completely. Measurements for studies of drainage (see table 2) first exercise every 30 seconds for 5 minutes. Then measurements recorded after 48 hours. Experiments carried out three times to ensure reproducibility.

Observed, as shown in table 1 that the solutions of at least 1 gpt Surfactant A saturated shale gasket is the faster, than 0.5 gpt Surfactant A, but the final volume saturation are the same.

The results of the drainage are presented in table 2, indicate that water reaches its maximum drainage volume very quickly, after just 2 minutes of drainage. (Note that the "volume of drainage is not the volume of fluid collected from the pipette, but rather a movement of the boundary between the fluid in the pipette, which is displayed using the ml-divisions in the pipette). But the volume of drainage water is very small compared with the volume of drainage water containing Surfactant A. the amount of drainage for 48 hours, the concentration of A Surfactant in water is not significantly affected, but the concentration of 1 gallon of A Surfactant per 1000 gallons of water (1 gpt Surfactant (A) and higher cause more draining than 0.5 gpt Surfactant A through the first five minutes of the drainage. The presence of A Surfactant in the fluid for processing increases the amount of fluid coming out of the shale gaskets, approximately 270%, compared to tap water.

Table 1

Filling time (the time required for complete saturation of shale gaskets, min:sec)
Surfactant Aof 0.5 gpt (ml)1 gpt (ml)4 gpt (ml)
TimeExperience 1Experience 2Experience 3Experience 1Experience 2Experience 3Experience 1Experience 2Experience 3Experience 1Experience 2Experience 3
0:151,51,53,03,53,02,42,62,62,73,43,03,5
0:302,52,54,04,44,54,54,04,54,54,54,44,5
0:453,04,04,65,05,05,05,05,05,05,05,05,0
1:003,54,55,0
1:15the 3.85,0
1:304,5
1:455,0
2:005,0

Table 2

The average value of three experiments the amount of fluid ejected from the pipette
Time (min:sec)Tap water (ml)of 0.5 gpt Surfactant A (ml)1 gpt Surfactant A (ml)2 gpt Surfactant A (ml)4 gpt Surfactant A (ml)
0:300,200,350,280,260,30
1:000,60 0,580,670,530,57
1:300,800,830,930,930,82
2:001,001,171,271,231,33
2:301,001,771,971,872,03
3:001,001,902,172,132,33
3:301,001,972,332,302,33
4:001,002,072,402,432,33
4:301,002,072,402,502,33
5:001,002,072,40to 2.572,33
After 48 hours1,002,733,032,772,60

Example 2

The ability of various materials to drainage and drainage estimate for samples of the Barnett shale using 2 gpt Surfactant A, 2 gpt Surfactant C (a mixture of isopropanol, 2-butoxyethanol, water and ethoxylated alcohols C11-C15), 2 gpt Surfactant B (a mixture of methanol, isopropanol, water, and ethoxylates of alcohols C9-C11 razvetvlennoy chain approximately 6 parts of EO per mole) and 0.25 gpt Friction Reducing Agent D (hereinafter sometimes referred to as the "FRA-D" (a mixture of acrylic polymer, heavy aliphatic naphtha, ethylene glycol, hydrotreated light distillate, oxyalkylated alkylphenol and water). Of these materials, only A Surfactant is a substance, drying slate, suitable for use in the present invention. Surfactant B and C represent the substance to impart wettability by water, which are typically used during initiation of inflow to the wells reservoir Sandstone and limestone to improve the recovery rate of the injected fluid to be processed. Two included additional studies show the ability to drainage slate water containing 1 gpt Surfactant A and 1 gpt Surfactant together with A 10 gpt scale inhibitor (hereinafter referred to as "SI"), available as PB 3525 from Nalco/Exxon Energy Chemicals, Houston, Texas, USA, and 10 ppt (pounds per thousand gallons) CaCl2.

The experimental methods. The core samples are crushed and the fragments screened between sieves 30/100 mesh. To determine whether additives useful during stimulus processing shale Barnett, doing research in several types. The study includes a qualitative comparison and (b) quantitative experiments on the drainage capillary.

a) Qualitative experiments. Study the project, studying the reaction of the material of the shale to a fluid environment for processing in chemical glasses, represent a qualitative comparison of trends slate to collapse/loosening in the fluid to be processed. Additional observations are made regarding the tendency of the fluid to handle to release and suspendirovanie fine particles of oil shale. Without intending to be bound by any theory of the present invention, assume that the fluid medium for processing that will not release fine particles in the fluid for processing water-based and do not contribute to suspendirovanie fine particles are preferred.

Qualitative experiments carried out to better understand the impact of solutions to handling the release of fine particles of oil shale. One gram of the material of slate placed in a 100 ml solution for processing. The container vigorously shaken to disperse fine particles. Then make observations on the fine particles settle to the bottom of the flask. The deposition of particles of shale indicates that they are wetted by the oil, and thus that they aglomerados or coalesce into the presence of an aqueous solution. This demonstrates that this Supplement can be effective in this picture the situation. When the shale particles remain in suspension, it indicates that they are wetted with water. Just prepare 10 solutions. The solutions prepared with fresh water or 2% KCl (mass in water) as the primary fluid are listed in table 3, together with a brief description of the results.

Table 3

A qualitative comparison: 1 g of material slate in fresh water and in fresh water with 2% KCl after vigorous shaking
The solution to handleFresh waterFresh water with 2% KCl
ControlFine particles float in the upper layer, the rest settle to the bottomFine particles float to the top layer, the other slowly settle to the bottom
2 gpt Surfactant CSlate is dispersed in water and begins to precipitate very slowly through 1/2 hoursAs a control, but with the slow subsidence
2 gpt Surfactant InSlate is dispersed in water and begins to precipitate through ˜10 minAs a control, but with slow subsidence
2 gpt Surfactant AndFine particles of shale flocculent and begin to settle down after 1 minThe entire slate of the Yan quickly sinks to the bottom
of 0.25 gpt Friction Reducing Agent DThe solution a milky appearance; slate begins to settle in 1.5 minA large part of the shale immersed very quickly, but some continues to emerge

Some notable observations are given here.

When A Surfactant is used as a potential dehydrating substances, fine particles of oil shale in 2% KCl in water very quickly sink to the bottom of the container and begin to sink to the bottom within one minute in fresh water before shaking flask. In all other cases, fine particles remain suspended on the surface of a fluid medium for processing until the flask vigorously't shake.

In the control experiments without additives there is some settling of the oil shale within one hour after vigorous shaking in fresh water and in fresh water with 2% KCl. However, more pop-particles appears when you use one of the additives.

The time of sedimentation of fine particles of oil shale in solution Friction Reducting Agent D after vigorous shaking, as it turns out, is the shortest regardless of whether the main fresh water or it contains 2% KCl (although slate settles even without shaking in the presence of A Surfactant and begins to settle faster than prisutstvie and Friction Reducting Agent D after shaking together with A Surfactant, and fine particles fall out of solution to handle containing A Surfactant, the second speed). After 4 minutes of fine particles in the flask with Friction Reducting Agent D are already on the bottom of the flask. However, studies of drainage, described below, demonstrate that Friction Reducting Agent D is not suitable for the substance to dry shale to the present invention.

In fresh water fine particles only very slowly deposited from solutions containing Surfactant B or C. Subsidence becomes a bit faster in 2% KCl, but the settling of particles slate is slower in any primary fluid with Surfactant B or C than in all other experiments, including controls without additives.

Fine particles fall out of solution for containing 2% KCl, faster than a similar solution for processing cooked in fresh water, that is, fine particles fall out of solution 2 gpt A Surfactant in water with 2% KCl faster than solution 2 gpt Surfactant A in fresh water.

After 24 hours, all the fine particles settle to the bottom of all solutions for processing.

(b) Quantitative experiments on capillary drainage. Experiments on drainage are here to show the effect of different fluid for processing shale drainage. The total amount of fluid is Reda, which follows from the gaskets of crushed slate, register (air displaces the fluid, which flows out of the gaskets). The greater the volume of water that flows out from the column, the more fluid environment for processing. Experiments on drainage are meaningful in relation to the reduction of surface tension and drying ability of the fluid to be processed. The total volume of drainage shale gaskets 30/100 mesh after 1 minute, 5 minutes and 24 hours are shown in table 4.

Table 4

The total drainage after periods of 24 hours
TimeThe volume of fluid for processing ejected from the gaskets (ml)
Fresh water1 gpt Surfactant A2 gpt Surfactant A2 gpt Surfactant B2 gpt Surfactant C2 gpt FRA-D1 gpt Surfactant A, 10 gpt SI, 10 ppt CaCl2
1 min-0,80,7------0,60,8
5 min-1,21,0-- ----1,11,3
24 hours0,81,31,41,71,650,71,21,00,61,11,3

Surfactant A has the best productivity for the drainage of all the studied additives. After 24 hours of stuffing leaked 1.7 ml of working solution with 2 gpt Surfactant A, compared with only 0.8 ml drainage of fresh water in 24 hours. Studies with different concentrations of Surfactant A show again (as in example 1)that increasing the concentration of A Surfactant can increase the amount of drainage. None of the surface-active substances, giving the wettability (Surfactant B or C), does not work as well as Surfactant A. moreover, the addition FRA-D based on polymers has very poor drainage characteristics. Finally, the addition of scale inhibitor has a minimal impact on the characteristics of Surfactant A.

The combined results of the qualitative and quantitative experiments of example 2 show superior performance Surfactant A, only one of the substances investigated in example 2, which is one of dehydrating substances of the present invention.

Example 3

The study of wetting exercise nations.com shale, using a modification of the method described in API Bulletin RP 42. The procedure consists of the following stages:

1. Filling glass jars with 50 ml of 2% KCl solution and adding 2 gpt surfactant.

2. Room 5 grams of crushed slate in the solution obtained in stage 1, and stirring for 60 seconds.

3. Decanting the liquid from the suspension obtained in stage 2, in another glass jar.

4. Add 50 ml of kerosene in a jar containing solid product slate.

5. Mixing slate and kerosene, observation dispersive ability of the pigment particles of shale.

6. Add 50 ml of fresh water into the system with stage 5; mixing and observation of dispersive ability of the pigment particles slate (this fresh water is considered as one flushing slate).

7. Filling another glass jars 50 ml of 2% KCl solution and adding 2 gpt surfactant.

8. Room 5 grams of crushed slate in the solution obtained in stage 7, and stirring for 60 seconds.

9. Decanting the liquid from the suspension obtained in stage 8, in another glass jar.

10. Add 50 ml containing no surfactants fresh water to the slate; shaking and decanting the liquid. Repeat washing and desantirovaniya slate with not containing surfactants fresh water su is th three times.

11. Add 50 ml of kerosene in a jar containing solid products of shale.

12. Mixing slate and kerosene; observation of dispersive ability of the pigment particles of shale.

13. Add 50 ml of fresh water to the system from the stage 12; mixing and observation of dispersive ability of the pigment particles slate (adding this fresh water is a fourth washing slate).

14. Comparison of results.

Examines the following surfactants:

Surfactant A,

Surfactant E: a mixture of 12.4% di-sec-butylphenol with 10 mol EO and 30.7% of dioctylamine chloride solvent

Surfactant F: Coco-aminopropionic,

Surfactant I: 50% FLUORAD FC-740 (fluorinated complex alkilany ether, available from 3M, St. Paul, Minnesota) in a heavy aromatic nafta from the distillation of crude oil.

These studies are carried out to demonstrate the effectiveness of various surfactants to impart slates wettability in oil. These studies are also designed to demonstrate the ability of surfactants to impart wettability of oil to be adsorbed on the slate after moderate flushing with fresh water. The ability of surfactants to impart wettability of oil to maintain wetted by the oil shale surface after washing shale with fresh water is important is, because the water in geological formations will not contain surfactants. If the surfactant is easily washed off from the surface of the shale, then the treatment will be of too short duration to be meaningful.

The results are summarized in table 5. Kerosene always represents the upper (lower density) liquid phase in all experiments.

Table 5

A summary of the study the wettability of slate
SystemOne freshwater flushFour flush fresh water
2 gpt A Surfactant in water with 2% KClFine particles are concentrated at the top (kerosene) layer. The layers remain slightly cloudyFine particles are concentrated at the top (kerosene) layer. Slight turbidity in kerosene and water
2 gpt Surfactant in water with 2% KClFine particles are easily dispersed in the water layer, while the kerosene layer is very muddyThe kerosene layer is significantly more transparent, fine particles remain concentrated and dispergirovannykh in the water layer
2 gpt Surfactant F in water with 2% KClThe transparent the aqueous layer, fine particles are well dispersed in kerosene layerFine particles remain highly aggregated and rolled with the boundary water layer
2 gpt Surfactant I in water with 2% KClSome fine particles are on the boundary of the upper layer of coarse emulsion of kerosene-water, with most of them are located in very turbid water layerThe kerosene layer is significantly more transparent, fine particles remain concentrated and dispergirovannykh in the water layer

After processing of fine particles of slate 2 gpt A Surfactant in water with 2% KCl and single or four-flush fresh water in the kerosene phase remain smaller particles of oil shale, as they are wetted by oil under the action of Surfactant A. the Aqueous phase is almost transparent, because the heavier particles of oil shale flocculent and settle on the bottom of the container. The appearance of the contents of the container is similar after one and four washes with fresh water, as the Surfactant A is so strongly adsorbed on the surface of the slate. This characteristic of strong adsorption is very important for the long-term results of treatment. Surfactant A is nebenabreden surface-active substance.

After treatment ODI fine particles slate 2 gpt Surfactant E to impart wettability of oil in water with 2% KCl and one rinse with fresh water fine particles of oil shale are present, first of all, on the boundary of coarse emulsion of kerosene-water, and the smaller fine particles are well distributed in the oil phase. However, using the fourth washing surfactant is washed out of the slate, as evidenced by the transparency of the oil phase indicating that this phase no longer contains dispersed particles of slate).

After processing of fine particles of slate 2 gpt foam, giving the wettability of the oil-Surfactant F in water with 2% KCl and one rinse with fresh water fine particles of oil shale treated with Surfactant F, are present primarily in the oil phase. The small fine particles are well distributed in the oil phase under the action of this gives the wettability of the oil-surfactant. Heavy fine particles flocculent and fall to the bottom of the aqueous phase, which is very transparent, which indicates the absence of dispersed wetted by water particles of slate. Even after four washes with fresh water Surfactant F continues to provide some of the wettability of the particles of shale oil. Particles remain strongly flokulirovannym on the interface and resist settling in the layer is still clear water. Surfactant F can form a stable foam, although there is no need to use is to use it only when foam is desired or necessary.

After processing of fine particles of slate 2 gpt giving the wettability of hydrocarbon foaming Surfactant I in water with 2% KCl and one rinse with fresh water fine particles are present primarily at the interfaces coarse emulsion of kerosene-water. Smaller fine particles of oil shale are well distributed in the aqueous phase, as indicated by the high turbidity of the water layer. Continued leaching of shale lowers the emulsification/foaming fluid and the shale is concentrated in a water layer, as indicated by the transparency of the oil phase.

Two imparting wettability of the oil-surfactant of the present invention, in this example, the Surfactant A and Surfactant F, create a stable surface slate, wetted with oil. Such stability is important to obtain long-term benefits of treatment. Another gives the wettability of the oil-surfactant, Surfactant E, failed to maintain the surface of the slate, wetted with oil, during the experiments, and Surfactant I did the surface of the slate wetted with water. Both results (wetted with water shale, and only very briefly wetted by oil shale) do not provide long-term benefits of treatment.

p> Example 4

Research drainage Devonian shale

A number of studies of drainage in extremely harsh conditions carried out to illustrate particularly strong adsorption of A Surfactant on the slate. The experiments carried out to evaluate the characteristics of the drainage and saturation agents, Surfactants A, E, F, G, H and I in the Devonian shales. Without intending to be bound by any theory of the present invention, assume that in these experiments the reduction of surface tension may play a more important role than in the experiments of example 3. The concentration of each surfactant used for the processing of oil shale, is equal to 1 and 5 gpt (gallons of additive per thousand gallons of water). Additionally, use of surface-active substances are:

Surfactant G: 2-butoxyethanol with linear ethoxylated alcohols C11-C15,

Surfactant H: Coco-benzylammonium chloride ethoxylate (with 2 mol of ethylene oxide).

The following information is logged during flow studies in the shale gaskets, and it is presented in the table 6:

1) the speed with which the fluid medium for processing fills the column with crushed Devonian slate.

2) the speed with which the fluid medium for processing stems from the column with crushed Devonian slate.

3) the Speed with which not containing the th surfactants, water flows from the column with crushed Devonian slate after as 90 volumes do not contain surfactants, water is passed through a column of Devonian shale.

Experiments on drainage indicate a decrease of the surface tension and the ability of the fluid to handle the drainage. The greater the volume of fluid that flows out of the pipette, the better the performance of the fluid to be processed. In addition, experiments on drainage, which are carried out after washing the column 90 volumes do not contain surfactants, water, show the strength of adsorption of surfactants on the slate. Sustainable adsorption of surfactants at the oil shale is highly desirable, since it should increase the duration of benefits processing.

Procedure. The sample of oil shale is crushed and the fragments screened between sieves 30/100 mesh. Fragments stuff (calling it shale gasket) in 5-ml pipette and hold it vertically with a sharp end of the pipette down. Mesh 100 mesh stuffed in the sharp end of a pipette, prevents the leaching of elements from the pipette. Fluid to be processed, containing surfactant, fresh water and 2% KCl, is blown into the upper part of the pipette using a 3-ml syringe. Initially shale gasket is dry, so it is possible OTS is eivat the fluid to be processed, when it saturates shale gasket (second column in table 6), and then flows out (the third and fourth columns in table 6). Time set to zero when the surface section of the fluid to be processed is lowered to the upper surface of the shale gaskets (fluid processing environment for now saturates the gasket and ready to start to leak from gaskets, allowing for admission of air from the top). The extent to which air enters the gasket due to a leak of the fluid to be processed, recorded as a function of time. Then after 24 hours of drainage 90 volumes of pores of fresh water (not containing surfactants or other additives) is passed through the shale gasket. This fresh water flushing simulates water, which comes from schist geological formations. Then follow with fresh water, when it flows from the gaskets (after washing 90 volumes of pores; the fifth and sixth columns in table 6). Time is again set to zero when the boundary surface of the fluid, such as water - falls to the surface of the shale gaskets (fresh water ready to start to leak from gaskets, allowing for admission of air from the top). The distance at which air enters the stuffing escaping freshwater register as fu is the Ktsia time.

Measurements carried out every 15 seconds for research "fill" up until shale gasket will not be filled completely. Measurements to study the drainage initially carried out every 30 seconds for 5 minutes. Then measurements recorded after 24 hours. Experiments carried out three times to ensure good reproducibility. (Again note that "the volume of drainage is not the volume of fluid collected from the pipette, and represents the movement of the boundary surface of the fluid in the pipette, as shown by ml-division in the pipette).

All fluids for processing shale fill stuffing within a time of 1:30 (min:sec) until 2:45 (min:sec). Four of the six investigated surfactants contribute to the wetting of the surface of the shale oil, or call him: Surfactant A, Surfactant E, Surfactant F and H. Surfactant G Surfactant is a surfactant that lowers the surface tension and imparts wettability by water, and Surfactant I is soluble in petroleum hydrocarbon foaming agent which imparts wettability of aluminosilicate minerals. Studies of primary drainage (column 3 demonstrates 15 minutes, and column 4 shows 24 hours) is presented to establish the baseline data for drainage of obrabotan the x surfactants Devonian shale. Giving the wettability Surfactant I is especially bad in studies of primary drainage at low concentrations. Other surfactants cause good drainage, due to their properties, associated with low surface tension. Good drainage is important for drainage shale geological formation and the creation of opportunities for excellent extraction of natural gas from wells. However, the stability of the wettability of the oil-surface represents a significant and main point, which makes the chemical composition of the present invention is significantly superior to conventional surfactants to impart wettability in oil. If the nature of the wetting oil is not sustainable, the ability to facilitate draining shale decreases rapidly as the extract does not contain surfactants water from geological formations. Comparison of average drainage volume after washing 90 volumes of pores of fresh water through the packing of the Devonian shale processed four surface-active substances, which impart wettability to oil (the fifth and sixth columns of table 6), shows that the Surfactant creates A state of wettability in oil that can withstand these studies in tough conditions. This drop is that resistance is particularly advantageous for the effective drainage of oil shale. Not shown, although Surfactant F (surface-active substance, which can form a stable foam) eventually almost completely removed from the surface of the shale in these exceptionally difficult to research, but it is removed more slowly than Surfactants E and H. That is, shale gaskets, machined surface-active substances, giving the wettability of oil other than the Surfactants A and F, as well as surface-active substances, giving the wettability, very quickly lose their ability to drain water, because these surfactants desorbers and do not provide more than their original advantages. Surfactant F is slowly losing its ability; A Surfactant (surface-active substance, which cannot form stable foams) does not demonstrate loss of ability even in this study, in extremely harsh conditions. Most notably, not all surfactants, which form a wetted by the oil surface, satisfy the requirements for satisfactory surfactants of the present invention.

Table 6

The research results of filling and dewatering of packings of the Devonian shale
The middle is s filling time (min: sec) Average drainage volume (ml after 15 min)Average drainage volume (ml after 24 hours)Average drainage volume (ml after 15 min) after 90 volumes then fresh waterThe average volume of drainage (ml, 24 hours) after 90 volumes then fresh water
1 gpt Surfactant A2:201,01,41,41,6
5 gpt Surfactant A2:151,11,31,41,6
1 gpt Surfactant E2:001,21,60,30,4
5 gpt Surfactant E2:451,42,00,40,6
1 gpt Surfactant F1:301,62,00,40,7
5 gpt Surfactant F2:451,62,10,30,9
1 gpt Surfactant G1:450,91,50,20,6
5 gpt Surfactant G2:101,52,70,20,4
1 gpt Surfactant H2:150,71,20,30,6
5 gpt Surfactant H 2:001,01,80,20,9
1 gpt Surfactant I2:050,20,70,20,5
5 gpt Surfactant I1:300,51,40,20,5
All studies are carried out three times. The data presented here are averages

Satisfactory performance in any of the previous examples indicate that the surfactant is suitable for use in the present invention.

Although the present invention is described in relation to a limited number of incarnations, specialists in this field will notice numerous modifications and variations. It is assumed that the appended claims cover all such modifications and variations as are within the scope and the essence of the present invention.

1. Method for draining schist containing hydrocarbons underground geological formations that contain adsorbed and compressed gas, includes stage i) bringing the geological formations in contact with an effective quantity of fluid for treatment of wells containing one or more obesogen the participating substances, under the action of which the geological formation becomes or remains wetted by oil; (ii) removing water from the geological formation.

2. The method according to claim 1, where the water is pre-removed from the geological formation.

3. The method according to claim 1, where the gas is pre-removed from the geological formation.

4. The method according to claim 1, where the fluid processing environment for the well further comprises an acid.

5. The method according to claim 1, where the fluid medium to the treatment well is foamed or energizerbunny and contains gas selected from the group consisting of nitrogen, air, carbon dioxide and mixtures thereof.

6. The method according to claim 1, where the fluid processing environment for the well further comprises a thickener.

7. The method according to claim 1, where the specified stage of bringing into contact with the geological formation includes pumping the specified fluid to the treatment well into the wellbore through the geologic formation at a speed and pressure required for fracturing the geological formation.

8. The method according to claim 1, where the fluid processing environment for the well further comprises an acid and where this stage of bringing into contact with the geological formation includes pumping the specified fluid to the treatment well into the wellbore through the geologic formation at a speed and pressure, DOS is enough to crack formation in geological formations.

9. The way to increase gas production from schist containing hydrocarbons underground geological formation that contains adsorbed and compressed gas, includes stage i) bringing the geological formations in contact with an effective quantity of fluid for treatment of wells containing one or more dehydrating substances, under the action of which the geological formation becomes or remains wetted by oil; (ii) removing water from geological formations; (iii) removal of gas from geological formations.

10. The method according to claim 9, where the water is pre-removed from the geological formation.

11. The method according to claim 9, where the gas is pre-removed from the geological formation.

12. The method according to claim 9, where the fluid processing environment for the well further comprises an acid.

13. The method according to claim 9, where the fluid medium to the treatment well is foamed or energizerbunny and contains gas selected from the group consisting of nitrogen, air, carbon dioxide and mixtures thereof.

14. The method according to claim 9, where the fluid processing environment for the well further comprises a thickener.

15. The method according to claim 9, where the specified stage of bringing into contact with the geological formation includes pumping the specified fluid to the treatment well into the wellbore passing through geologic formation, when soon the tee and pressure, sufficient to crack formation in geological formations.

16. The method according to claim 9, where the fluid processing environment for the well further comprises an acid and where this stage of bringing into contact with the geological formation includes pumping the specified fluid to the treatment well into the wellbore through the geologic formation at a speed and pressure required for fracturing the geological formation.

17. The method according to any one of claims 1 or 9, where the aforementioned dehydrating substance selected from the group consisting of

a) organic compounds which are surface-active substances having the formula

R1-(EOx-PrOy-BuOz)H,

where R1 is an alcohol, phenol or a derivative of phenol or fatty acid having from 1 to 16 carbon atoms, EO represents ethyleneoxide group, x is equal to from 1 to 20, PrO represents propylenoxide group, equal to from 0 to 15, BuO is butyleneglycol group, z is equal to from 1 to 15;

(b) organic polietileniminov having the formula

R2-(-CH2-CH2-O-C(O)-O-)qH,

where R2 is an alcohol having from 7 to 16 carbon atoms, and q is from 7 to 16;

(c) butoxycarbonyl glycols having from 1 to 15 butylaniline groups;

(d) ethoxylated-butoxysilane the different glycols, having from 1 to 5 ethyleneoxide groups and from 5 to 10 butylaniline groups; and

(e) alkylaminocarbonyl acids or carboxylates.

18. The method according to 17, where alkylaminocarbonyl acid or carboxylate has the formula

R-NH-(CH2)n-C(O)OX,

where R represents a saturated or unsaturated alkyl group of 6-20 carbon atoms, n is from 2 to 6, X is a hydrogen or a cation forming a salt.

19. The method according to p, where n is equal to from 2 to 4.

20. The method according to claim 19, where n is equal to 3.

21. The method according to claim 20, where the surfactant is cocoamidopropyl.

22. The method according to 17, where organic surface-active compound is a product of the interaction tridecylalcohol alcohol, ethylene oxide and butilenica.

23. The method according to item 22, where organic surface-active compound is a branched tridecylamine alcohol having about 7.5 ethylenoxide links and about 3.5 butylaniline links.

24. The method according to any one of claims 1 or 9, where the specified schist containing hydrocarbons underground geologic formation that contains adsorbed and compressed gas, pre-treated using a method selected from the group consisting of hydraulic fracturing, hydrocollator tear, repairs and acidification./p>

25. Drilling fluid or solution for well completion, containing dehydrating agent for shale selected from the group consisting of

a) organic compounds which are surface-active substances having the formula

R1-(EOx-PrOy-BuOz)H,

where R1 is an alcohol, phenol or a derivative of phenol or fatty acid having from 1 to 16 carbon atoms, EO represents ethyleneoxide group, x is equal to from 1 to 20, PrO represents propylenoxide group, equal to from 0 to 15, BuO is butyleneglycol group, z is equal to from 1 to 15;

(b) organic polietileniminov having the formula

R2-(-CH2-CH2-O-C(O)-O-)qH,

where R2 is an alcohol having from 7 to 16 carbon atoms, and q is from 7 to 16;

(c) butoxycarbonyl glycols having from 1 to 15 butylaniline groups;

(d) ethoxylated-butoxycarbonyl glycols having from 1 to 5 ethyleneoxide groups and from 5 to 10 butylaniline groups;

(e) alkylaminocarbonyl acids or carboxylates.



 

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4 cl, 1 ex, 3 dwg

FIELD: oil and gas production.

SUBSTANCE: invention relates to production of proppants, i.e. splitting granules, used in oil and gas production via breakdown way. Proppant of invention is obtained from caked two-component aluminosilicate fees in the form of granules with density 2.2-3.0 g/cm3 and 0.2-2.5 mm in size consisting of nucleus and shell, wherein one of components of aluminosilicate feed, which forms granule nucleus is a low-alumina substance containing less than 30% of alumina: coal combustion ashes, preliminarily fired kaolin, nepheline, nepheline syenite, feldspar, shale, or alumina production slime waste, and other component of aluminosilicate feed, which forms granule shell, is a high-alumina substance containing above 70% alumina: alumina dust of electrofilters of aluminum hydroxide calcination furnaces, industrial alumina, preliminarily fired bauxite, and exhausted catalysts based on active alumina form. Feed contains 50.0-95.0% low-alumina substance and 5.0-50.0% high-alumina component. In a method for production of proppant from two-component feed including (i) granulation upon addition of binding component in mixer-granulator provided with plate cup rotating at constant speed and rotor-type stirrer whose rotation speed is varied in dependence of granulation stage, (ii) drying, (iii) sizing of fried granules, (iv) firing of granules in rotary furnace, and (v) sizing of fired granules to form commercial fractions, when obtaining above-indicated proppant, low-alumina substance is used in the first granulation stage and, after granules 0.15-2.0 mm in size are formed, second granulation stage comprises addition of high-alumina substance into granulator followed by further granulation until granules 0.2-2.5 mm in size are obtained. Preliminary firing of low-alumina substance (as defined above) is carried out at 700-1200°C and the same of high-alumina substance (as defined above) at 700-1400°C. Firing of dried granules id effected at 1100-1600°C. Binding substance is used in the form of aqueous suspension of an organic binder (carboxymethylcellulose, methylcellulose, low-grade lignosulfates) of aqueous suspension of clay, wherein concentration of suspended binder is 1.0-10.0%. Aqueous suspension is added during granulation process in amounts 10.0 to 40.0% of the weight of initial feed.

EFFECT: enabled production of proppants from accessible raw materials (production wastes) without complication of existent technology.

9 cl, 1 tbl, 14 ex

FIELD: oil and gas production.

SUBSTANCE: in a method of preparing propping agent including grinding, hydration, molding, drying, and calcinations of raw material, the latter is natural bentonite clay containing more than 90% montmorillonite, molding of spherical granules of propping agent 200 to 400 μm and 420 to 850 μm in size involves spray drying technique and molding of granules more than 850 μm in size is accomplished using beading process, and calcinations is carried out at 600-650°C. Method is applicable for use in intensification of oil and gas inflow from producing beds.

EFFECT: reduced expenses of hydraulic fracturing of formation.

2 tbl

FIELD: oil and gas production.

SUBSTANCE: fluid contains, wt %: industrial-grade powdered lignosulfonates 26.4-31.7, potassium chloride 4.9-5.9, aluminum sulfate 1.2-1.50, borax 0.4-0.5, formation water 40.3-44.7, and sweet water in proportion to formation water as 1:(1.98-1.99).

EFFECT: improved process parameters due to improved structurally mechanical properties of fluid, raised viscosity thereof, high sand-retention ability, and possibility of controlling lifetime without loss in high technological characteristics.

1 tbl, 2 ex

FIELD: oil and gas production.

SUBSTANCE: proppant used in oil production involving hydraulic fracturing of formation contains ceramic granules coated with novolac resins supplemented by catalytic aqueous urotropin solution in organosilicon emulsion. Proppant preparation method comprises preparing granules and coating them. The latter operation is carried out as follows. Granules are heated to 150-160°C, dry novolac resin and catalytic urotropin solution are added at stirring in two equal portions with respect to the weight of resin and urotropin. When dropping temperature achieves 95-100°C, organosilicon emulsion is added provide following proportions of ingredients: 5.0-8.0% of novolac resin, 1.5-3.0% of 33% urotropin solution, 0.1-0.3% of organosilicon emulsion, and ceramic granules - the rest. Granules are finally cooled. Organosilicon emulsion is prepared at emulsion-to-water ratio 1:10.

EFFECT: increased strength of ceramic proppant and improved its quality due to resin coating applied with separating emulsion.

2 cl, 1 dwg, 1 tbl, 2 ex

FIELD: ceramics.

SUBSTANCE: invention relates to manufacture of molded ceramic materials for use as propping agent in production of liquid and gaseous fluids from bored wells. Method comprises briquetting and heat treatment of aluminosilicates kaolin at 1150-1250оС. Resulting mix is ground to average grain size 3-5 μm and loaded into granulator. Before granulation, 1.2-3.0% mineralizer and 5-10% plasticizer are added. Mix is moistened with dozed amount of organic binder and stirred to form granules. At the end of granulation, fired ground material for powdering granules is added in amount 1.2-3.0%. Granules are dried and screened to isolate desired fraction, which is subjected to final firing at 1370-1450оС for 30-60 min and then re-screened into commercial fractions.

EFFECT: enabled manufacture of granules having low loose density and high strength allowing their use at depths up to 14000 feet (4200 m).

3 cl, 1 dwg, 1 tbl, 3 ex

The invention relates to the field of technology molded ceramics and can be used for the manufacture of ceramic rasklinivanie oil and gas wells

The invention relates to the production of granular refractory materials intended for use as a proppant (lining) with the oil and gas extraction method of hydraulic fracturing

The invention relates to the production technology of ceramic materials and can be used to produce lightweight, high-strength ceramic granules of spherical shape of proppants used in the hydraulic fracturing of rocks as a proppant

FIELD: oil production industry, particularly to develop oil and gas condensate deposits with the use of chemical reagents and to isolate permeable formations made up of terrigenous reservoirs with pore heterogeneity.

SUBSTANCE: method involves injecting gel-forming composition in watered formation, wherein the gel-forming composition comprises katamin AB used as gel formation rate regulator and taken in amount of 0.05-0.1 % by weight, ceolite component used in synthetic detergent production and taken in amount of 7.00-10.00% by weight, hydrochloric acid in amount of 7.00-12.00% by weight, remainder is water. Above composition is held in formation for time period necessary for gel formation, namely for 0.5-3 days and then water is injected in formation via injection well.

EFFECT: increased technological efficiency and oil and gas condensate deposit development efficiency due to gel-forming time regulation.

2 tbl, 1 ex

FIELD: oil and gas production, particularly to perform repair-and-renewal operations in wells to reduce sand ingress in well and to consolidate geological formations, including artificial ones after hydraulic formation fracturing.

SUBSTANCE: method involves injecting water-free liquid in well, wherein water-free liquid contains polyurethane pre-polymer and solvent; injecting water in well; hardening thereof. The polyurethane pre-polymer is hydrophobic polyurethane pre-polymer. The solvent is lower ketone. Above substances are taken in the following amounts (% by weight): hydrophobic polyurethane pre-polymer - 5.0-15.0, lower ketone - 85.0-95.0. Volume of the liquid is equal to 0.4-5.0 pore volumes. Injection time does not exceed 3 hours. After liquid injection the injection is stopped and well is left as it is for not less than 10 hours in static conditions to provide liquid hardening.

EFFECT: increased efficiency of sand appearance control without noticeable collecting properties decrease.

1 ex, 1 tbl

FIELD: oil production industry, particularly to treat bottomhole formation zone and injection wells, which are converted from producing wells.

SUBSTANCE: method involves injecting solvent composition mixed with surfactant in formation; forcing composition in formation; performing time delay and putting well in operation. Before the composition forcing in formation the composition is held at face within the limits of well filter location for 1-2 hours in dependence of filter contamination with asphalt-tar-paraffin deposits or activating technical means usage. The solvent is distillation residue obtained during ethylbenzene and A or B grade styrene rectification. The surfactant is grade B liquid sulphanole taken in amount of 1-10% by the distillation residue weight.

EFFECT: increased efficiency, reduced time and material consumption for bottomhole formation zone treatment.

FIELD: oil production industry, particularly to stimulate oil production with the use of chemical reagents.

SUBSTANCE: method involves injecting solution through injection well via tubing string; providing solution decomposition to generate heat; injecting water; lifting oil via productive wells. The solution is 50% hydrogen peroxide and solution volume is equal to 0.3 of void volume. Hydrogen peroxide is supplied between two plugs with the use of liquid, which is inert to hydrogen peroxide. Volume of above liquid is equal to 1.1 tubing string volumes. Catalyst, for instance potassium hydroxide, is injected in well before the first plug forming. Potassium hydroxide volume is equal to 0.1 hydrogen peroxide volume. After two plugs forming 5% solution sodium permanganate is supplied in well and then oil is displaced to producing wells by water. The liquid, which is inert to hydrogen peroxide, is acetate bumper.

EFFECT: increased efficiency of residual oil production due to improved action on bound water.

2 cl

FIELD: gas condensate deposit development, particularly to increase productive reservoir output at later stage of well operation without formation pressure retaining when hydrocarbon condensate forms in producing well bottom zone.

SUBSTANCE: method involves performing periodical well bottom zone cleaning of hydrocarbon condensate generated as a result of formation pressure reduction by supplying solvent, which solves hydrocarbon condensate, in reservoir, wherein the solvent is mixture including acetone and pentane-hexane fraction; holding well as it is for condensate solving; removing the obtained solution from well bottom zone during well putting in operation. Before pentane-hexane fraction injection in well the fraction is saturated with gaseous hydrocarbon up to pressure of 0.3-1 MPa so that equilibrium gas blanket is created over liquid pentane-hexane fraction. Gaseous hydrocarbon mainly contains methane. Above pressure is maintained during mixture injection in reservoir.

EFFECT: increased output from producing gas condensate wells due to improved hydrocarbon condensate removal from pore space and well bottom zone reservoir permeability recovery.

2 ex, 3 tbl

FIELD: oil and gas production.

SUBSTANCE: in a formation permeability control composition comprising aluminum salt solution (20-40 vol %) and alkali reagent, the latter is liquid zeolite production waste, namely mother liquor MP-X or MP-Y containing sodium silicate and admixture of corresponding zeolite NaX or NaY, pH of solution being 12-14.

EFFECT: enhanced plugging capability of composition due to increased volume of precipitate and reduced solubility thereof in formation water.

1 tbl, 4 ex

FIELD: oil production, particularly means to increase oil recovery from reservoirs and during oil and gas well overhaul.

SUBSTANCE: method involves treating polyacrylamide powder contained in air-tight bag with ionizing radiation, wherein 5-50 l bag is used; serially treating polyacrylamide powder having 0.1-4 mm particle dimensions with accelerated electrons having 0.4-12 MeV energy by half of 1-10 Mrad dose from each opposite bag side having maximal surface area, wherein polyacrylamide powder layer thickness is not more than 30 cm and the bag is located on metal tray; holding polyacrylamide powder in bag for at least 24 hours. The tray may be formed of steel, lead or wolfram. Oil production method involves injecting aqueous oil-recovery suspension in reservoir, wherein the oil-recovery suspension is obtained by polyacrylamide powder treatment with ionizing radiation. Above reagent has the following fraction composition (% by weight): particles having 0.11 mm diameters - 30-70; remainder is particles having 1-4 mm diameters. Reagent concentration in the suspension is 0.1-1.5%.

EFFECT: increased gel particle strength under high pressure gradients reservoir treatment.

2 cl, 3 ex

FIELD: oil production, particularly to develop non-uniform oil reservoir with flooding thereof.

SUBSTANCE: method involves injecting aqueous polymeric composition plug in well, wherein the aqueous polymeric composition contains polyacrylamide treated with ionizing radiation and water. The aqueous polymeric composition is 0.5-2% aqueous suspension of extremely swollen polyacrylamide. Solid polyacrylamide is treated with 1-10 Mrad dose of ionizing radiation. Before polymeric composition plug injection 5-30% suspension having polyacrylamide suspended in organic water or aqueous sodium silicate solution having 1.1-1.5 g/cm3 and swollen up to 0-20 index is injected in reservoir to be treated. The aqueous suspension additionally contains filler in amount of 0.1-10 % by weight. Suspension is prepared with the use of water having pH-2-5. Aqueous suspension additionally includes water-soluble salt of bivalent or trivalent metal taken in amount of 3-10% by weight.

EFFECT: increased efficiency of high-temperature oil reservoir development due to increased isolation quality along with increased oil recovery.

5 cl, 4 ex

FIELD: oil and gas industry, particularly oil and gas production with the use of perforators using direct fluid action, for instance abrasive jets.

SUBSTANCE: method involves performing full-waveform logging along with full wave signal recording in digital form; detecting place and number of cuts performed by hydraulic jet perforation along formation height. Bottomhole assembly includes hydraulic jet perforator, pressure test unit having socket for drop ball receiving, pipe string with measuring band connected to the first clutch and provided with cut marks, as well as reference connection pipe. Above components are arranged in bottom-up direction. Pipe string provided with equipment is lowered in well so that perforator reaches level of lower cut, which is the first from bottom. Then the first slot-like cut is formed in two stages by supplying abrasive liquid to perforator. At the first stage perforation is carried out under working pressure of up to 20 MPa for not more than 25 min. Just after that the second stage perforation operation is carried out under working pressure of up to 30 MPa for not more than 20 min. Above operations are fulfilled for each cut. After the last cut perforation channels of hydraulic jet perforator nozzles are closed and perforator valve assembly is opened. Slot-like channels are cleaned of sand. Perforator is lowered to well bottom and well is flushed until clean formation water appears. Then inflow stimulation liquid in injected into perforation interval and into area located 50-100 m over the perforation interval and repeated full-waveform logging of the inflow stimulation liquid is executed along with full wave signal recording in digital form. Perforator is lifted to day surface. After than immersed pump or equipment for flowing well operation are lowered in producing well or working agent injection equipment is lowered in injection well. Inflow stimulation liquid is removed from well bore and the well is brought into operation.

EFFECT: increased efficiency of secondary productive formation exposing.

FIELD: oil production industry, particularly to develop oil deposits having flooded reservoirs with non-uniform permeability.

SUBSTANCE: method involves flooding reservoir; injecting oil-and-bitumen product plug in reservoir, wherein the oil-and-bitumen product is obtained via production wells from highly-viscous oil and bitumen fields; producing oil from productive wells. Samples of oil-and-bitumen product taken from j-production wells are previously analyzed to determine aliphatic property Aj thereof. Then aliphatic properties Aj of the samples are compared with that (An) of native oil. If Aj> An the oil-and-bitumen product plug is used for water-saturated reservoir zone plugging. If Aj< An above plug is used to stimulate difficult-to-recover oil displacement. Plugs of oil-and-bitumen products having Aj> An and Aj< An may be jointly injected in reservoirs characterized by non-uniform permeability.

EFFECT: increased efficiency due to usage of oil-and-bitumen product having predetermined properties and adapted to increase filtration resistance in flushed zones having high permeability and to improve relative oil permeability in reservoir zone having low permeability.

3 cl, 2 ex, 2 tbl

FIELD: oil and gas production.

SUBSTANCE: invention relates to polymer drilling fluids used in boring of gas and oil wells, in particular to clay-free biopolymer drilling fluid, which are used when performing boring under complicated mining and geological conditions, including those in chemogenous deposits and at high borehole temperatures and also in cases of directional wells and horizontal well sites. Biopolymer drilling fluid of invention contains, wt %: polymeric filtration reducer: polyanionic cellulose or carboxymethylcellulose, or oxyethylcellulose, or hydrolyzed polyacrylonitrile, 0.1-1.0; xanthane-type biopolymer, 0.2-0.5; fatty acid ethylenediamides: condensation product of ethylenediamine and phosphatide concentrate, 0.05-3.0; alkali metal humates: coal-alkali reagent or humate-potassium reagent, 3,0-6.0; alkali and/or alkali metal salts: KC, NaCl, CaCl2, MgCl2; bischofite, 3.0-40.0; and water in balancing amounts.

EFFECT: reduced amount and concentration of components required to prepare drilling fluid at the same inhibitory, lubricating, filtration, and antiadhering properties, improved structural-rheological properties, heat and salt resistance, and reduced harmful environmental effects.

2 tbl

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