Application of degradable fibers in solutions of inverted emulsions for well killing

FIELD: oil-and-gas industry.

SUBSTANCE: method of processing underground bed comprises injection of emulsion inverted solution in cased borehole cutting the bed to well killing. Said method comprises: oily continuous phase, nonoleaginous disperse phase and at least one bridging agent. formation contact with well killing solution and possibility for degradable material to degrade at least partially. Proposed method comprises: production of inverted emulsion for well killing including: oily continuous phase, nonoleaginous disperse phase and at least one bridging agent, injection of said solution in encased perforated borehole, production of filtration crust and its destruction to mallow the material to degrade. Proposed method comprises: production of inverted emulsion for well killing including: oily continuous phase, nonoleaginous disperse phase and at least one bridging agent. Placing the well killing solution in said borehole, formation of filtration crust and destruction of said crust whereat hydrolysis of degradable material destructs said crust.

EFFECT: higher efficiency, minimised bed damages.

25 cl, 2 tbl, 5 dwg

 

BACKGROUND of INVENTION

The scope to which the invention relates.

As described here implement in a General sense refer to the solutions for plugging wells used in the completion of oil and gas wells.

The level of technology

Solutions for plugging wells is usually placed in the wellbore during well operation of an oil field, for example completions to plug the well, i.e. to prevent the flow of formation fluids into the wellbore and the loss of well fluid into the reservoir until the well is open. The solution for plugging wells are often kept in the wellbore throughout the operation.

Traditional solutions for killing well known in the prior art typically are aqueous solutions that contain a weighting agent, such as an inert inorganic solid substance in solution or suspension, to increase the density of the solution. The weighted mud to kill the well exerts hydrostatic pressure on the layer of fluid that is greater than the pressure of formation fluid, trying to break into the wellbore. This hydrostatic pressure, with a positive differential, prevents the flow of reservoir fluids into the wellbore during run-Yes the exploitation wells oil field, what is required from the operational point of view to prevent interference from reservoir fluids, as well as from the point of view of safety, to prevent an uncontrolled blowout and blowout.

The weights often include weighted solutions for killing the well, to provide suppression filter into the reservoir. Filtration of the slurry is undesirable to cause formation damage, i.e. to reduce the permeability, leading to reduced production or reduced injectivity of the formation.

In particular, the preferred solution for plugging the wells are solutions which do not only prevent the flow of formation fluids into the wellbore, but also prevent appreciable leakage of well fluid into the reservoir. Solutions for plugging wells provide control over the leakage of fluids through the presence of special solids, which is based on the buildup of mud cake on the surface of the layer for suppressing flow into the reservoir and through him. However, these additional materials can cause serious damage in areas close to the wellbore, after their application. This damage can significantly reduce production levels, if the permeability of the formation will not be restored to its original level. Next, approach the present moment in the operation completion filtration crust you want to delete, to restore the permeability of the formation, preferably, to its original level.

After any operation completion is made, it may be necessary to remove mud cake formed from a solution for plugging wells remaining on the side walls of the wellbore. Although the solution for plugging wells may be significant to the operations completion, barriers can represent a significant obstacle to the extraction of hydrocarbons or other fluids from a well, for example, if rock is still blocked by the barrier. Because filtration cortex is compact, it is often strongly adheres to the reservoir and can with difficulty and not completely flushed out of the reservoir under only one action solution.

Accordingly, there is a need in the solution for killing the well, which can effectively reduce the inflow and outflow fluid between the reservoir and the well bore during the operation completion and minimizes formation damage.

The INVENTION

In one aspect described herein embodiments of relate to a method of processing a subterranean formation, which comprises the injection into a cased, perforated wellbore that intersects the formation of a solution for plugging wells, representing a converted Amul the plain, moreover, the solution turned emulsion for killing wells includes: an oily continuous phase, nemesistwo dispersed phase, emulsifying agent, at least one biodegradable material and at least one bridging agent; a contact layer with a solution for plugging the well; and allowing the degradable material to at least partially decompose.

In another aspect, described herein embodiments of relate to a method that includes obtaining the solution turned emulsion for killing the well, and the solution turned emulsion for killing wells includes: an oily continuous phase, nemesistwo dispersed phase, emulsifying agent, at least one biodegradable material and at least one bridging agent; injection solution for plugging wells in a cased, perforated wellbore that intersects the formation; formation of mud cake; and the destruction of the mud cake, allowing the degradable material to degrade.

In another aspect described herein embodiments of relate to a method that includes obtaining the solution turned emulsion for plugging wells comprising: an oily continuous phase, nemesistwo dispersed phase, emulsifying agent, at least one different is the proposed material and at least one bridging agent; the location solution for plugging wells in a cased, perforated wellbore; forming a mud cake; and the destruction of the mud cake, in which the hydrolysis of the degradable material breaks filtration crust.

Other aspects and advantages of the invention will be apparent from the following description and the accompanying claims.

BRIEF DESCRIPTION of DRAWINGS

Figure 1 is a schematic illustration of the mud cake deposited in the perforation channels after injection solution for killing under option exercise under this description.

Figure 2 shows a picture of the solution turned emulsion mixed with degradable fibers according to one variant of implementation.

Figure 3 shows a photo of the mixture shown in figure 2, after 100 hours at 93°C.

Figure 4 shows a picture of the solution turned emulsion mixed with degradable fibers on the Aloxite disk according to one variant of implementation.

Figure 5 shows a photo of the mixture, shown in figure 4, after 168 hours at 79°C.

DETAILED DESCRIPTION

First, it should be noted that during the development of any such actual option exercise must be carried out numerous incarnations-specific solutions, h is ordinary to achieve the developer's specific goals, such as compliance related systems and business-related constraints, which will vary from one implementation to another. Moreover, it will be clear that such development could be a complex and time-consuming, but, nevertheless, would be a routine task for specialists in this field, having the benefit of this description. The description and examples are presented solely for the purpose of illustration the preferred embodiments of the invention, and they should not be construed as limitations of the scope of patent protection and the applicability of the invention. While the compositions of the present invention are described as comprising certain materials, it should be understood that the composition can optionally include two or more chemically different materials. In addition, the composition may also include some components that are different from those that have already been quoted.

In the invention, and in this description, each numerical value should be interpreted as modified by the term "about" (unless it is already so clearly not modified) and then re-interpreted as unmodified thus, unless otherwise specified in the context. In addition, in the invention, and in this detailed description it should be understood that the concentration is the range, listed or described as applicable, suitable or equivalent means that any and every concentration within the range, including the boundary values should be considered as specified. For example, range from 1 to 10" should be interpreted as showing without exception, all the possible numbers in a continuous interval of about 1 to 10. Thus, even if specific data points within the range, or even no data points within the range, are explicitly identified or refer to only some specific points you need to understand that the inventors appreciate and understand that any or all of the experimental points within this range should be considered as specified and that the authors of the invention described and made available the full range and all points within the given range.

In one aspect described herein embodiments of relate to the treatment solution for plugging wells used in completion operations, to reduce or prevent penetration and the expiration of the fluid between the reservoir and a cased, perforated wellbore. In particular, the described embodiments of are solutions of inverted emulsions for killing SK is Ainy, containing degradable fibers and bridging agent, which can effectively clogging and to isolate (by formation of mud cake) perforation tunnels formed in a productive zone cased and perforated wells so that you can perform other operations completion. Because the fibers are biodegradable, processing may be temporary, allowing you to easily destroy filtration peel and remove it from the wellbore without damage or minimal damage to the formation. Thus, the solution for plugging wells according to the present description can include oily continuous phase, nemesistwo dispersed phase, degradable fiber bridging agent and at least one surfactant/emulsifying agent to stabilize oily and amelanistic phase as the inverted emulsion. Each of the components of the solution will be discussed in turn.

Degradable materials

Degradable materials may include solid materials such as fibers that are soluble and hydrolyzed in base, such as solid cyclic dimer or solid polymers of some organic acids, which are easily hydrolyzed into soluble products in the presence of a base. Such degradable fibers can be obtained slacktide, glycolide, polylactic acid, polyglycolic acid, copolymers of polylactic acid and polyglycolic acid, copolymers of glycolic acid with other monomers containing hydroxyl, carboxyl or hydroxycarboxylic part of the molecule, copolymers of lactic acid with other monomers containing hydroxyl, carboxyl or hydroxycarboxylic part of the molecule, or mixtures thereof.

Additional examples of other biodegradable materials include substances described in a publication Polymer Science, vol. 157, "Degradable Aliphatic Polyesters", edited by A. C. Albertson (2001). Specific examples include homopolymers, statistical, block, graft, star-shaped and hyperbranched aliphatic polyesters. Polyesters can be prepared, for example, by polycondensation reactions, polymerization with ring opening, free radical polymerization, coordination polymerization with ring opening and any other appropriate way. Specific examples of suitable polymers include aliphatic polyesters, polylactide, polyglycolides, poly-ε-caprolactone, polyhydroxybutyrate, polyanhydrides, aliphatic polycarbonates, poly(ortho)esters, polyaminoamide, polyphosphazene and similar polymers.

The above degradable materials may consist solely of particles SL is the author of polyester, for example, the composition for injection may contain no or essentially not contain nepoliarnae solids, or complex polyester you can, alternatively, mix or mix with other degradable or soluble solids, for example, solids that interact with the products of the hydrolysis, for example, magnesium hydroxide, magnesium carbonate, dolomite (magnesium-calcium mixed carbonate), calcium carbonate, aluminum hydroxide, calcium oxalate, calcium phosphate, metaphosphate aluminum, sodium zinc potassium polyphosphate glass, and sodium calcium magnesium polyphosphate glass. In addition, examples of the reactive solids, which can be added include crushed quartz (or it is silica powder), oil soluble resin, degradable rock salt, clay, such as kaolin, illite, chlorite, bentonite or montmorillonite, zeolites, such as chabazite, clinoptilolite, heulandite, or any synthetically produced zeolites, or mixtures thereof. Biodegradable materials may also include waxes, oil-soluble resins and other substances that decompose or become soluble upon contact with hydrocarbons. It is believed that biodegradable materials break down, when at least one physical or chemical property of the material and the changes from its original state. For example, the material may be subjected to hydrolysis or other physical or chemical change over time, which changes one or more of its observable physical or chemical properties.

Degradable material may be in the form of strips, plates, fibers, flakes, or in any other form with a size ratio equal to or greater than one. Degradable materials may include particles having an aspect ratio more than 10, more than 100, 200, 250, or equivalent, for example, plates or fibers or similar. In addition, the mixed material can take any form composites, for example, coatings or backbone of the biodegradable material containing buried them in other materials. Next, degradable particles may be a nano-, micro - or mesoporous structures that are fractal or refractility.

Typical fibers include, but are not limited to, polyester fibers of polylactic acid, polyester fiber from polyglycolic acids, fibers of polyvinyl alcohol and similar. Further illustrative fibers include polyester fibers, is coated to be highly hydrophilic, such as, but not limited to, polyethylene terephthalate (PET) fiber DACRON™sold by Invista Corp. Wichita, Kansas, the school is, 67220. When using the solutions according to the present description of the fibrous component may be included at concentrations of about 5 to 29 kg/m3the liquid phase of the solution, and, more specifically, the concentration of fibers may be from about 11 to 23 kg/m3. However, the person skilled in the art will understand that you can use other quantity.

Additional information pertaining to the appropriate degradable materials can be obtained from U.S. patent No. 7265079, 7350573 and 7066260, which are fully incorporated here by reference.

Bridging agents

Examples of bridging agents suitable for use in the present description, include calcium carbonate, dolomite (MgCO3·CaCO3), barium sulfate (barite), ilmenite, hematite, olivine, siderite, Galena, magnesium oxide, iron oxide, strontium sulfate, cellulose, mica, propping agents such as sand or ceramic particles, and combinations thereof.

To achieve plugging or clogging of the perforations, it is possible to choose a specific treatment (type(s) of particle geometry(AI) particle concentration(AI) and distribution(I) of particle sizes), so that bridging agents were temporaroly or was clogging the mouth of the perforation, and fine particles can then form a dense filtration crust behind sukupolvi the particles, thus forming the insulation and the regulation point. Particle size can also be chosen so that the bridging agent is received in the perforation and deposited it in the dehydration process as the liquid phase of the solution for plugging the well penetrates into the reservoir. Further discussion of the choice of the particle size required for the initiation of the closure can be found in SPE 58793, which is fully included here by reference.

The concentration of the bridging agent may vary depending on, for example, from the wellbore/reservoir, which is used to seal the agent, and, in particular, on the characteristics of perforations, and the leak rate of the fluid. However, the concentration should be at least large enough to seal agent was clogging or canonrebel perforation in the wall of the wellbore, but it should not be so high as to make room solution impractical.

Classification bridging agent sizes can also be made based on the size of the perforations in the wellbore and/or size of the pore channels of the formation. In one embodiment, bridging agent has an average particle diameter in the range from 50 to 1500 microns, and from 250 to 1000 microns in another embodiment. However, in each the x implementation options you can use particles, having an average particle diameter less than 50 microns. For example, in particular embodiments, the implementation can be used fine particles with d90in the range from 1 to 25 microns and d50in the range from 0.5 to 10 microns, for example, the particles described in U.S. patent No. 6586372, 7267291 and 7449431 and publications, U.S. patent No. 2007/0184987, 2006/0188651 and 2005/0101492, which are incorporated here by reference in its entirety. The expression d90and d50represent the diameters of the particles, when the percentage by volume or by weight of particles of a given diameter, compared with the total volume or total weight of the sample is 90% and 50%, respectively. Also inside the volume of patent protection of the present description is adjudged that any bridging agents can optionally be covered with a material dispersant, similarly as described in U.S. patent No. 6586372, 7267291 and 7449431 and publications, U.S. patent No. 2007/0184987, 2006/0188651 and 2005/0101492.

Bridging agent may include essentially spherical particles; however, it is also envisaged that the bridging agent may include an elongated particles, for example, rods, flakes, sheets or fibers. When bridging agent comprises an elongated particles, the average length of elongated particles should be such that elongated particles were capable of plugging or zakopalova the July artificially formed cracks in their mouth or close to it. Typically, elongated particles may have an average length in the range from 25 to 2000 microns, preferably from 50 to 1500 microns, more preferably from 250 to 1000 microns. Bridging agent can be sorted by size, so that it is easy to form a bridge or tube at the mouth of the perforations or close to it. In addition, in some embodiments, the implementation of the bridging agent may be wide (polydisperse) distribution of particle sizes; however, in another case, you can use other distributions.

Inverted emulsion

As discussed above, the solution to kill the well from the present description may be an inverted emulsion, i.e. emulsion, in which amalananda liquid represents the dispersed phase and the oily liquid is a continuous phase.

The oily phase may be a liquid and more preferably is a natural or synthetic oil and more preferably, oily liquid selected from the group including diesel oil, mineral oil, synthetic oil, such as hydrogenated and digidrirovannye olefins, including poly-alpha-olefins, unbranched and branched olefins and similar, polydiorganosiloxane, siloxanes or organosiloxanes, esters of fatty acids, specifically Alki the performance communications esters of fatty acids with unbranched, branched chain or cyclic, mixtures thereof and similar compounds known to the person skilled in the art; and mixtures thereof. The concentration of the oily liquid should be sufficient to have formed facing the emulsion, and the concentration of the oily liquid may be less than about 99% by volume of the volume of the inverted emulsion. In one embodiment, the amount of oily fluid is from about 30% to 95 volume% of the volume of the solution turned emulsion and, more preferably, from about 40% to 90 volume% of the volume of the solution turned emulsion. In one embodiment, oily liquid may include at least 5 volume% of a material selected from the group comprising esters, ethers, acetals, diallylmalonate, hydrocarbons, and combinations thereof.

Amalananda phase used in the formulation described here, the solution turned emulsion, can be a liquid and, preferably, may be a water-based liquid. More preferably, amalananda the fluid may be selected from the group including sea water, brine containing organic or inorganic dissolved salts, a liquid containing miscible with water and organic compounds, and combinations thereof. The number amelanistic liquid is t typically is less than theoretical limit required for the formation of the inverted emulsion. Thus, in one embodiment, the number amelanistic fluid is less than about 70 volume% of the volume of the solution turned to the emulsion, and preferably from about 1% to 70 volume% of the volume of the solution turned emulsion. In another embodiment, amalananda liquid, preferably approximately from 5% to 60 volume% of the volume of the solution turned emulsion.

In addition, to stabilize emulsions typically include emulsifying agents and emulsifying systems. Used here emulsifier, emulsifying agent and surfactant are used interchangeably. Emulsifying agent serves to reduce the surface tension of liquids so that amalananda liquid could form a stable dispersion of small droplets in the oily liquid. A full description of such inverted emulsions can be found in the Composition and Properties of Drilling and Completion Fluids, 5thEdition, H. C. H. Darley, George R. Gray, Gulf Publishing Company, 1988, pp. 328-332, the contents of which are hereby included by reference.

Emulsifying agents that can be used in the described solutions include, for example, fatty acids, soap-based fatty acids, amidoamines, polyamides, polyamine, oleate esters such as orbitonasal, sorbitanoleat, imidazoline derivatives, or derivatives of alcohols, and combinations or derivatives of the above. In addition, the solution may also contain surfactants, which can be characterized as wetting agents. Wetting agents that may be suitable for use in the described solutions include crude tall oil, oxidized crude tall oil, complex organic phosphate esters, modified imidazolines and amidoamines, alkylaromatic sulfates and sulfonates, and similar substances, and combinations thereof, or derivatives. However, when used with the solution turned emulsion using wetting agents based on fatty acids should be minimized so as not to adversely impact on reversereport described here inverted emulsion. FAZE-WET®, VERSACOAT®, SUREWET®, VERSAWET® and VERSAWET® NS are examples of commercially available wetting agents manufactured and distributed by M-I L.L.C., Houston, Texas, which can be used in the described solutions.

In a particular embodiment, the inverted emulsion may be of the reversible type, resulting in inverted emulsion can be converted from the emulsion of the type water-in-oil" emulsion of the type oil-in-water" under the influence of, for example, acids. Such is bratonia solutions based oils include systems, described, for example, in U.S. patent No. 6806233 and 6790811, which are fully incorporated here by reference.

In addition, the solution turned emulsion for killing wells under this description, you can add lime or other alkaline material to maintain a reserve of alkalinity. The generally accepted role of the reserve alkalinity is to promote the conservation of viscosity and stability of the inverted emulsion. In the absence of reserve alkalinity acid gases can weaken the stability of the solution turned emulsion to the critical point. In other words, the emulsion becomes so unstable that the continuous oily phase and dispersed amalananda phase irreversibly "reversed". In addition, reserve alkalinity may also serve to facilitate solubility and/or destruction degradable material described above, so that they can be either hydrolyzed and contribute to the fragmentation or destruction of mud cake from the inverted emulsion. In a particular embodiment, it is possible to add lime (or other suitable alkaline materials)to amalananda phase could be equivalent to a pH value of at least 8,3 or more than 10 or 11 in other variants of the implementation.

For the preparation of the described solutions for plugging wells you can use the usual methods in a manner than is primary is usually used for cooking traditional liquid-based oils. In one embodiment, the desired amount of oily liquid, such as base oil, and a suitable amount of surfactant are mixed together and then, with continuous stirring, add the remaining components. Inverted emulsion also can be obtained by vigorously shaking, stirring or moving the oily liquid and nemesistwo liquid.

However, in a specific embodiment, a formulation of the solution for plugging the well can be, mixing together the desired amount of oily liquid, such as base oil, and a suitable amount of surfactant. Degradable fibers can be added to amelanistic liquid before mixing with the oily liquid. As soon as oily liquid (surface-active substance) and nemesistwo liquid (with fibers) are added to each other, to this mixture, you can add lime or other alkaline materials, followed by adding bridging agents. Inverted emulsion can be obtained by vigorously shaking, stirring or moving the mixture.

As mentioned above, the solution turned emulsion for killing wells under this description, you can enter or otherwise placed in a perforated wellbore in a productive zone, i.e. very near to the with perforation channels. The solution for plugging wells contains degradable fibers and bridging agents that can effectively clogging and to isolate (by formation of mud cake) perforation tunnels.

When destruction/hydrolysis of the degradable fibers released a weak organic acid, which may also contribute to the dissolution of the bridging agents (depending on the type of the selected bridging agent). Even if there is minimal dissolution of the bridging agents, filtration cork may break (or break down) due to the destruction of fibers and fiber Mat. Used herein, the term "fragmentation" or "the destruction of the mud cake" refers to the decrease in the number of mud cake or increase its permeability by dissolving at least part of the filter cover. Depending on the type of solution released acid can also pay emulsion (from reverse to direct)when used reversible solution, as described above. In this example, the residual solution/filtration crust may exist in the form of direct (oil-in-water) emulsions, and not in the form of inverted (water in oil) emulsion. When the solution is not reversible, the remaining solution/filtration cork can exist in two phases.

In the threaded depending on the downhole environment (often 79-149°C) degradable fibers can decompose into soluble hydrolysis products, promoting the removal of mud cake without even a single stage of leaching. A special variant of implementation may include backwashing filtration residue cover using a drilling fluid or formation fluid produced in situ from the reservoir after the formation of mud cake. In another embodiment, stratiform liquid can be extracted directly from the reservoir without an intermediate rinse liquid in the well to remove the remnants of the mud cake.

Figure 1 shows a variant implementation of the casing 10 with perforation channels 14 in the productive interval 16, where the filtration cortex 17 was deposited in the perforation channels 14 to prevent the flow of fluids into the reservoir for cleaning away the debris of rock, formed by the perforation, and/or still had another operation completion.

Examples

The following examples are presented to illustrate the preparation and properties of fluid systems, and they should not be construed as limiting the scope of protection of the invention unless otherwise explicitly specified in the attached claims. All percentages, concentrations, ratios, parts, etc. are mass, unless otherwise specified or not obvious from the context of their use.

Were fabricated and tested a few what to solutions of inverted emulsions for killing the well.

Solution 1 contains water (73% vol./vol.), mineral oil (27% vol./vol.), VERSACOAT™ (6-10 hours/billion (17.1 to 28.5 kg/m3)), which is a surfactant sold by M-I L.L.C., Houston, Texas, lime (11,4-17,1 kg/m3), 1,13 SG (1,130 kg/m3) CaCl2(64% vol./vol.), calcium carbonate with a size of 2 microns (28,5-85,6 kg/m3), calcium carbonate with a size of 10 microns (28,5-85,6 kg/m3and degradable fibers (12-18 kg/m3)sold by Schlumberger Technology Corporation, sugar Land, Texas. The concentration of fibers in solution 1 is 18 kg/m3and the solution 2 contains the same components as the solution 1, except that the concentration of fibers is 12 kg/m3.

Solution 3 is a reversible emulsion system, which includes water (52% vol./vol.), mineral oil (48% vol./vol.), VG-PLUS (a 2.9-8.6 kg/m3), organogenous clay sold by M-I L.L.C., Houston, Texas, in the form VG-Plus, FAZEMUL® (22,8-34.2 kg/m3), which is a surfactant sold by M-I L.L.C., Houston, Texas, lime (11,4-17,1 kg/m3), 1,28 SG (1,280 kg/m3) CaCl2(41% vol./vol.), calcium carbonate with a size of 2 microns (28,5-85,6 kg/m3), calcium carbonate with a size of 10 microns (28,5-85,6 kg/m3and degradable fibers (12-18 kg/m3)sold by Schlumberger Technology Corporation, sugar Land, Texas.

Solution 1 was tested to dissolve the particular fibers with sampling bottles, to determine the time until complete dissolution of the fibers (hydrolysis). The results showed that at 93°C fibres are dissolved in about 100 hours, when exposed to solution 1. After 100 hours at 93°C, as illustrated in figure 2 (up) and figure 3 (after), the fibers dissolve in the system, and can be formed layers of oil, residual calcium carbonate and calcium lactate.

The rheology of the solutions were determined on a Fann viscometer 35, supplied by Fann Instrument, and filtering properties were measured using the test determine the rate of filtration under high pressure and at high temperature at 3447 kPa and 79°C. table 1 compares the rheological properties of the three solutions, including plastic viscosity (PV), the maximum shear stress (YP) and electrical stability (ES).

Table 1
Rheology (about./min)123 (Fazepro)
60010112368
300658043
2005 6233
100343922
6879
3768
Plastic viscosity (PA·s)being 0.0360,0430,025
The limiting shear stress (PA)13,8617,688,6
Electrical stability (In)5836433

Table 2
Solution 1Solution 3
Filtering
(ml)
With fibersLint - With the ox CNAME Lint -
Sharp emission0,51,542,5
1 min22,57of 5.4
4 min2,62,896,8
9 min2,8310,88,6
16 min2,93,612the 9.7
25 min3a 3.913,210,2
30 min3,64,213,510,6
36 minthe 3.84,414.4V10,8
1 hour 4,4515,513,2

Tests under high pressure and at high temperatures were carried out in cell loss, using 3-micron Aloxite disks. As shown in figure 4 (up) and 5 (after), after 168 hours at 79°C fibers dissolve and interact with most of the carbonates in the sample, leaving the disk without residual fibers or carbonate bridging particles.

Embodiments of the present description can provide at least one of the following advantages. The solution turned emulsion containing degradable materials based on fibers and bridging agents, can serve as a solution for killing wells (temporary treatment wells) in a cased, perforated wellbore to temporarily minimize the penetration and the expiration of liquids through the channels of perforation, while you can perform the operation completion. At the completion of the transactions completion solution for plugging wells can samorazrushatsya through decomposition of materials based on biodegradable fibers in water and at high temperatures, reducing the number of remaining solids. Hydrolysis of the fibers may also contribute (to some extent) in the dissolution zakopalova the General agents, as well as the treatment of the emulsion, when used reversible emulsion.

While the invention has been described, referring to a limited number of embodiments, the experts in this field, having the benefit of this description will understand that you can come up with other ways of implementation that do not deviate from the scope of patent protection of the invention described here. Accordingly, the scope of protection of the invention should be limited only by the attached claims.

1. Method of treatment of a subterranean formation, comprising:
the injection into a cased, perforated wellbore that intersects the formation of the solution turned emulsion for killing the well, and the solution turned emulsion for killing wells contains:
oily continuous phase,
nemesistwo dispersed phase,
emulsifying agent,
at least one degradable material and,
at least one bridging agent;
the contact layer with a solution for plugging wells and
providing opportunities degradable material to at least partially decompose.

2. The method according to claim 1, wherein the degradable material comprises at least one substance selected from lactide, glycolide, polylactic acid, polyglycolic acid, copolymers of polylactic acid and polyglycolic acids is, copolymers of glycolic acid with other monomers containing hydroxyl, carboxyl or hydroxycarboxylic part of the molecule, copolymers of lactic acid with other monomers containing hydroxyl, carboxyl or hydroxycarboxylic part of the molecule, or mixtures thereof.

3. The method according to claim 1, wherein the degradable material is hydrolyzed within a certain period of time.

4. The method according to claim 3, in which the biodegradable material is hydrolyzed, releasing organic acid.

5. The method according to claim 4, in which the organic acid draws the solution for plugging the well so that the oily phase is the dispersed phase, and amalananda phase is a continuous phase.

6. The method according to claim 1, in which the solution for plugging the well further includes lime.

7. The method according to claim 1, in which the bridging agents include at least one substance selected from calcium carbonate, dolomite, barium sulfate, ilmenite, hematite, olivine, siderite, Galena, magnesium oxide, iron oxide, strontium sulfate, cellulose, mica, propping agents or mixtures thereof.

8. The method according to claim 1, in which the oily phase comprises from about 30% to 99% by volume of the total solution for killing the well.

9. The method according to claim 1, in which the oily phase is selected from diesel oil, mineral oil, Shin is micheskogo oil, ester oils, glycerides of fatty acids, aliphatic esters, aliphatic ethers, aliphatic acetals, or combinations thereof.

10. The method according to claim 1, in which amalananda phase is from about 1% to 70% by volume of the total solution for killing the well.

11. The method according to claim 1, in which amalananda phase selected from fresh water, sea water, brine, aqueous solutions containing water soluble organic salts, water soluble alcohols or water soluble glycols, or combinations thereof.

12. The method according to claim 1, wherein the emulsifying agent comprises at least one substance selected from fatty acids, soap-based fatty acids, amidoamines, polyamides, polyamines, aleath esters, imidazoline derivatives, or derivatives of alcohols or their combinations or derivatives thereof.

13. The method including:
obtaining the solution turned emulsion for killing the well, and the solution turned emulsion for killing wells contains:
oily continuous phase,
nemesistwo dispersed phase,
emulsifying agent,
at least one degradable material and,
at least one bridging agent;
injection solution for plugging wells in a cased, perforated wellbore that intersects the formation;
which is of mud cake; and
the destruction of the mud cake, allowing the degradable material to degrade.

14. The method according to item 13, in which the degradable material comprises at least one substance selected from lactide, glycolide, polylactic acid, polyglycolic acid, copolymers of polylactic acid and polyglycolic acid, copolymers of glycolic acid with other monomers containing hydroxyl, carboxyl or hydroxycarboxylic part of the molecule, copolymers of lactic acid with other monomers containing hydroxyl, carboxyl or hydroxycarboxylic part of the molecule, or mixtures thereof.

15. The method according to item 13, in which the biodegradable material is hydrolyzed within a certain period of time.

16. The method according to item 15, in which the biodegradable material is hydrolyzed, releasing organic acid.

17. The method according to clause 16, in which the organic acid draws the solution for plugging the well so that the oily phase is the dispersed phase, and amalananda phase is a continuous phase.

18. The method according to item 13, in which the solution for plugging the well further includes lime.

19. The method according to item 13, in which the bridging agents include at least one substance selected from calcium carbonate, dolomite, barium sulfate, ilmenite, hematite, olivine, siderite, Galena, oxide mA the tion, iron oxides, strontium sulfate, cellulose, mica, propping agents or mixtures thereof.

20. The method according to item 13, in which the oily phase comprises from about 30% to 99% by volume of the total solution for killing the well.

21. The method according to item 13, in which the oily phase is selected from diesel oil, mineral oil, synthetic oil, ester oils, glycerides of fatty acids, aliphatic esters, aliphatic ethers, aliphatic acetals, or combinations thereof.

22. The method according to item 13, in which amalananda phase is from about 1% to 70% by volume of the total solution for killing the well.

23. The method according to item 13, in which amalananda phase selected from fresh water, sea water, brine, aqueous solutions containing water soluble organic salts, water soluble alcohols or water soluble glycols, or combinations thereof.

24. The method according to item 13, in which the emulsifying agent comprises at least one substance selected from fatty acids, soap-based fatty acids, amidoamines, polyamides, polyamines, aleath esters, imidazoline derivatives, or derivatives of alcohols or their combinations or derivatives thereof.

25. The method including:
obtaining the solution turned emulsion for plugging wells that contain:
oily continuous the ABC,
nemesistwo dispersed phase,
emulsifying agent,
at least one degradable material and,
at least one bridging agent;
premise solution for plugging wells in a cased, perforated wellbore;
the formation of mud cake; and
the destruction of the mud cake,
in which the hydrolysis of the degradable material breaks filtration crust.



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: method for optimising extraction from a well is proposed, in which an artificial lifting system in a well shaft is controlled, and multiple parameters of extraction on surface and in the shaft well are monitored. A well model with calculated data parameters is built. Then, measured data on working face and surface of the well is compared to the model data and reliability of the measured data is checked. After that, difference between measured data and modelled data is diagnosed, and operation of an artificial lifting mechanism is adjusted as per the above diagnostics results.

EFFECT: ensuring enlargement of analysis volume of a well and components of an extraction system for effective extraction optimisation as a whole.

FIELD: oil and gas industry.

SUBSTANCE: well is equipped bottom upwards with a tubing string ended with a packer, submerged pump, switch, two outer and inner annulus of the tubing string which are located concentrically, tubes with holes at the outer tubing string. The well is splitted over the productive stratum. The stratal product is delivered by the submerged pump in a cyclic mode "delivery-stop" from the productive stratum through the tubing string, the switch, tubular annulus between inner and outer tubing string, tubes and holes of tubes into tubular annulus between the production string and outer tubing string. Pressure is created and maintained in the upper pert of the well; it should not be less than oil degassing pressure and more than permissible pressure to the production string. Separation of the stratal product into oil and water is arranged in the upper part of the well. Completeness of separation is controlled by the duration of a half of the operation cycle of the submerged pump till stoppage and by the distance between switch and the tube with a hole. Oil is delivered to oil line. Water is supplied through the switch to inner tubing string and through the pipeline to an injection well by borehole-to-borehole water pumping and/or through tubular annulus between the production string and outer tubing string and tubing string with a packer to the stratum over the packer by borehole water pumping.

EFFECT: improvement of oil and water separation degree, increase in injection efficiency of separated water during borehole and borehole-to-borehole pumping of water.

1 ex, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: device contains a spherical body with at least one segment containing at least one section of throttle joints and one limiting. Stream is fed to the segment from the butt end, through side channels. Each input unit can be covered by a roller gate of the plug with thread which is input through the chamber body.

EFFECT: increasing oil recovery of the formation.

12 cl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves lowering to the well of a pipe string with a cable, control devices in the form of electric valves, pressure and temperature measuring sensors and with one or several packers isolating the borehole space. Sensors are used, the information from which is supplied to a measuring unit installed on the well head. Signals for opening and closing of control devices are supplied via the cable from the wellhead control unit. The product is lifted to the surface by means of a pump via inter-tube space. The well is built with a horizontal section passing in the formation with different permeability zones. Packers are installed in the horizontal section of the well, thus separating the formation zones with different permeability. The inter-tube space is isolated with a plug, above which there arranged one above another are upper and lower control devices arranged in a vertical shaft and equipped with measuring sensors. Zones with equal or similar permeability are interconnected with each other by being grouped in two flows interconnected with the borehore space and the input of the upper control device or the inter-tube space and the input of the lower control device. Outputs of control devices are interconnected with the pump inlet, and the value of opening of control devices is derived with frequency separation via one cable, via which parameters are picked up from measuring sensors, as per the readings of which the value of opening of each of the control devices is determined. Each control device is made in the form of an electric motor with a reduction gear, which are arranged in the housing, the rotating shaft of which is connected through a screw-nut connection to a pusher and a valve having the possibility of tight interaction with a seat, below which there arranged is a shell with an inlet in the form of channels, in which a compensating chamber with elastic walls is arranged, which is filled with lubricating liquid and interconnected with inner space of the pusher and sealed space located above the pusher.

EFFECT: enlarging manufacturing capabilities in wells with zones of different permeability, and reducing costs.

2 cl, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: method lies in accumulation of liquid and gas in a well, cyclic carryover of accumulated liquid from the liner to tubing string and throwing of liquid column by gas. According to the invention associated gas is separated from liquid-gas mixture and directed to the upper part of gas-lift unit to gas burning unit. Air under high pressure is fed to the same unit in order to provide conditions for gas-air mix burning ensuring high-speed burning process accompanied by sharp increase of temperature and pressure. In result it provides opening of return valve in the lower part of tubing string and throwing of liquid column by gas being a combustion product. Thereafter cycle of gas separation from liquid-gas mixture and its burning in gas-air mix is repeated as far as liquid and gas enter through the service valve from annular space to the lower part of submerged gas-lift unit at receipt of a signal from the earth control station.

EFFECT: increase in efficiency, reduction of power consumption, control of production process and reduction of costs for well operation.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method consists in movement of a housing of a continuous circulation tool to an adapter having a channel passing through it and intended for connection in a pipe string in the well and selective movement of drilling fluid between the housing and a side hole in the adapter; in addition, the continuous circulation tool includes a shutoff device, and actuation of a shutoff mechanism to introduce a shutoff element of the shutoff device through the side hole in the adapter for insulation of drilling fluid flow through at least one section of the channel. A system for carrying out well operations with continuous circulation of drilling fluid, which contains a continuous circulation tool interconnected with a tubular column of the well, which contains an adapter and is intended for selective shutoff of the drilling fluid flow to tubular column of the well, a pipe manipulating device near the adapter, which contains the following: a pipe wrench, pipe wrenches, a pipe wrench, a retaining wrench, a pipe wrench and a spinning wrench and a device for mechanised suspension and unscrewing of pipes.

EFFECT: maximum drilling speed.

34 cl, 27 dwg

FIELD: oil and gas industry.

SUBSTANCE: system and method for increasing a well flow rate are described in the application. The system includes processor (150) that processes commands contained in a software, which include command for monitoring during the specified period of time of an actual fluid flow rate from each productive zone (52B, 52b) of the well in compliance with the first tuning of devices for control of the flow rate and applying the analysis of the chain using a method of node potentials to a variety of input data chosen from the data of well sensors, data of surface sensors, one or more current positions of devices, for the purpose of setting one or more new settings, at which increase in the well flow rate will be provided.

EFFECT: increasing productive capacity of well.

18 cl, 6 dwg

FIELD: oil and gas industry.

SUBSTANCE: system includes several tubular elements located in each other with the channels directing the fluid flows from different formations of the well to different channels of tubular elements fixed in the casing pipe by means of packers. Channels are equipped with spool-type gates with control electric drives providing separate movement of fluid flows from different formations through different channels by means of a processor and a fluid parameter measurement sensor installed in each channel and functionally connected to the automatic control processor of the valve in compliance with the information received from the sensor, and further selective mixing of flows in the area of the casing pipe. Tubular elements are fixed in the casing pipe with upper packer, and at their inlets, they are connected to the coupling directing different flows via different channels from different formations, which is connected via a central channel by means of the shank to the extracting device of the product from bottom formation of the well, which is fixed in the casing pipe with lower packer. Unit of separate supply and accounting is connected via a branch pipe to the electric drive of the submersible centrifugal pump, in which a communication cable is placed to control the valves from the electric feed and control cable, which attaches the pump electric drive to the well electric feed and control station.

EFFECT: increasing operating efficiency of the well formations.

3 cl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes blocking of a perforation interval by means of injection of a blocking liquid and its pushing with a killing fluid to a bottomhole and to a bottomhole area of a bed with simultaneous monitoring of pressure at a well head, gas relief and process settling. At the same time, prior to injection of the blocking fluid, a sand screen is formed by injection of a pulp of quartz sand with fraction of 0.6-1.2 mm in a carrier fluid in two portions with a flow rate of a carrier fluid, the value of which does not exceed the maximum permissible value, defined according to the formula. At the same time the volume of the quartz sand in the first portion of the pulp is calculated in accordance with the formula with further process settling of the well for the time determined according to the formula after injection of the first pulp portion. The volume of the quartz sand in the second pulp portion is taken as equal to the volume of suffosion channels produced in the sand screen. The blocking fluid is a certain composition. The blocking fluid volume is previously calculated according to the formula. Besides, at the moment of completion of blocking fluid pushing, hydrodynamic pressure is determined in a tubing string. Afterwards the process settling of the well is carried out. Further injection of the killing fluid into the well is carried out along the tubing string until it appears at the well head. At the same time the well head pressure is controlled in the annular space of the well by means of gas and blocking fluid relief, providing for pressure at the inlet to the tubing string as permanent and equal to the predetermined hydrodynamic pressure.

EFFECT: improved efficiency of gas well killing.

1 tbl

FIELD: oil and gas industry.

SUBSTANCE: design of low-angle and horizontal wells includes a technical string, an operating string and a lift string. The operating string is cemented above the productive formation roof. The operating string in the productive formation is divided into sections with casing packers, and sections include filter sections and sections of solid pipes. The lift string in the productive formation is equipped with operating packers, installed inside the sections of solid pipes of the operating string and groups of controlled valves equipped with calibrated inlet side holes arranged inside filter sections. A seat nipple is installed at the end of the lift string. Controlled valves and the nipple are made as capable of interaction with control devices lowered inside a lift string.

EFFECT: possibility to control an inflow from isolated sections of a low-angle or horizontal well shaft or their total selective water isolation.

3 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: composition for changing the underground formation permeability includes expandable polymer micro particles which comprise hydrophobic polymer with labile side groups. Said micro particles feature mean diameter of non increased volume making 0.05 to 5000 mcm. Said hydrophobic polymers comprises ethers of acrylic acid and comonomers copolymerised with acrylic acid ether and labile side groups are hydrolysable. Proposed invention covers also the method of changing the underground formation permeability including injection of proposed composition into formation.

EFFECT: simplified control over underground bed permeability.

18 cl, 2 tbl, 11 ex

FIELD: oil-and-gas industry.

SUBSTANCE: proposed composition comprises 100 wt % of silicic acid ethyl or methyl ether or mixes thereof, 15-50 wt % of polar solvent, 1-3 wt % of chlorides of IV-VIII group metals, and additive representing polypropylene in amount of 0.1-0.5 wt %.

EFFECT: controlled solidification time, shorter fluidity loss time, higher efficiency of isolation and plugging-back.

1 tbl

Well killing fluid // 2499019

FIELD: oil-and-gas industry.

SUBSTANCE: well killing fluid comprises the following components in wt %: glycerin - 20.0-35.0, sulphacell - 1.2.0, ammonium iodide - 60.0-62.5, water making the rest.

EFFECT: efficient killing of wells with seam pressure exceeding hydrostatic pressure.

1 tbl, 1 ex

FIELD: oil and gas industry.

SUBSTANCE: oil and/or gas extraction system contains: mechanism of drainage of at least part of sulphur-containing compound to the formation and mechanism for processing of at least part of sulphur-containing compound to carbon sulphide or carbon oxysulphide by means of reaction with at least of a part of sulphur-containing compound with hydrocarbon. At that the above mechanism for processing is located inside the formation.

EFFECT: increasing efficiency of inventions due to sufficient energy saving.

21 cl, 8 dwg

FIELD: mining.

SUBSTANCE: method includes circulation of a system of drilling mud and efficient quantity of a foaming composition, made of a foaming agent and a stabilising polymer, addition of a gaseous agent into a liquid with speed sufficient to form a foam drilling mud and removal of the foamed drilling mud from a well. Drilling is carried out on the self-sacrificing foam, which is supplied into a well along the closed circulation cycle by means of pumping through a plant for circulation and regeneration of the self-sacrificing foam by means of injection of the self-sacrificing foam into a drilling string, direction of the flow of the self-sacrificing foam with rock sludge after evacuation from the well along the chute system into a sump for regeneration, soaking in the sump until self-sacrificing, return to the stage of addition of the gaseous agent for repeated foaming and return into the well. The foaming composition is a composition of the self-sacrificing foam on the basis of carbamide resins, previously modified with ammonia chloride, sulfanol, second group metal chlorides and water.

EFFECT: invention provides for high indices of technical characteristics of foam, such as half-life and expansion ratio of foam, and also stability and resistance of foam, improved environmental condition around a well, reduced prime cost of works.

10 cl, 4 dwg, 9 tbl

FIELD: chemistry.

SUBSTANCE: besides carbamide nitrate, the composition contains not more than 4% moisture and up to 1% phosphorus-containing component (with respect to orthophosphoric acid). The phosphorus-containing component used is phosphorus compounds, such as orthophosphoric acid and substituted derivatives thereof, for example oxyethylidene diphosphonic acid, nitrilotrimethylphosphonic acid, including stoichiometrically balanced in a composition in form of a salt, particularly in form of carbamide salts. A method of producing the composition is also disclosed.

EFFECT: invention broadens the range of chemical agents for removing carbonate deposits, scales, corrosion products and other products.

4 cl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to construction of oil and gas wells, particularly light-weight plugging materials used to cement over-producing intervals of gas, gas condensate or oil wells, primarily with a high gas-oil ratio, higher than 100 m3/t. The plugging material according to one version contains, pts.wt: oil-well portland cement PTST 1G-CC-1 80.0-87.0, hollow aluminosilicate microspheres 10.0-15.0, a stabilising additive - re-dispersible vinyl acetate and acrylate copolymer 3.0-5.0, fluid loss reducing agent - oxyethyl cellulose 0.2-0.3, plasticiser - polyester carboxylates or a substance whose active component is sulphonated melamine formaldehyde 0.1-0.2, antifoaming agent - modified organosilicon reagent POLYCEM DF 0.2-0.3, setting accelerator - calcium chloride 2.0-3.0, water - the balance, wherein the total weight content of the dry mixture of portland cement, hollow aluminosilicate microspheres and the stabilising additive is equal to 100 pts.wt; and according to the second version, the light-weight gasproof plugging material contains, pts.wt: oil-well portland cement PTST 1G-CC-1 76.0-86.0, hollow aluminosilicate microspheres 10-16, a stabilising additive - redispersible vinyl acetate and acrylate copolymer 3.0-6.0 and a reagent Conmix H2Ostop, the active component of which is sodium silicate 1.0-2.0, fluid loss reducing agent - oxyethyl cellulose 0.1-0.2, plasticiser - a substance whose active component is sulphonated melamine formaldehyde 0.1-0.2, antifoaming agent - modified organosilicon reagent POLYCEM DF 0.2-0.3, setting accelerator - ethyl silicate condensate 0.5-2.0, water 57-60, wherein the total weight content of the dry mixture of portland cement, hollow aluminosilicate microspheres, re-dispersible vinyl acetate and acrylate copolymer and the reagent Conmix H2Ostop is equal to 100 pts.wt.

EFFECT: two versions of a light-weight plugging material with improved gasproofing properties while also providing the optimum required properties for quality cementing of over-producing intervals in low and normal temperature conditions, specifically: low filtrate volume with low filtration rate and controlled time of formation of static shear stress.

2 cl, 2 tbl

FIELD: oil and gas industry.

SUBSTANCE: device for treatment of a bottom-hole formation zone of an oil well includes an air chamber with atmospheric pressure and a receiving chamber made from light-weight elasto-plastic material. In the receiving chamber a provision is made for composite materials of cylindrical shape: slightly gassy material and material that generates gas at combustion, and in addition, the receiving chamber of the device includes composite material that generates gas and acid at combustion between slightly gassy and gas-generating composite materials. Slightly gassy composite material at combustion, which faces the air chamber and is fixed with radially located metal pins relative to the receiving chamber housing, is made of composition containing the following, wt %: agranulated ammonium nitrate grade B 45-46, potassium bichromate 1-2, epoxy resin grade ED-20 40-42, plasticising agent grade EDOS 2-3, hardening agent Agidol grade AF-2M 9-10. Gas- and acid-generating composite material at combustion is made of composition containing the following, wt %: ammonium nitrate 40-50, powder-like fluorine rubber grade SKF-32 with dispersity of 0.5-1.5 mm 10, chlorinated paraffin wax grade KhP-1100 10-30, and fluoroplastic grade F-32L 10-40. Composite material that generates gad at combustion is made of composition containing the following, wt %: ammonia nitrate 78-85, powder-like nitryl butadiene rubber with dispersity of 0.5-1.5 mm 12, and potassium bichromate 3-10.

EFFECT: improving efficiency of a device owing to complex thermogas-dynamic and chemical action on a bottom-hole formation zone of an oil well, reducing slag formation relative to weight of the device by 3-5 times, and simplifying the device manufacture.

1 tbl, 5 ex, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: in selection method of polymer gel-forming composition to increase oil recovery of formations and waterproofing work based on acrylamide polymer, a cross-linking agent and water, which involves determination of formation parameters for a certain well, experimental determination of characteristics of the above composition, including time of gel formation and static shear stress, calculation of initial pressure gradient, minimum radius of a gel screen and minimum volume of pumped composition, distance Rk in a zone that is located at some distance from injection well working face and where a gel screen shall be formed is set, temperature value is defined for the above distance as per the pre-built diagram of dependence of distribution as per distance in the formation of temperature values calculated considering temperature of pumped water, its pumping rate and time, temperature, porosity and heat conductivity of the formation, and pressure value as per the pre-built diagram of dependence of distribution as per the distance in the formation of pressure values designed as per the specified formula, and composition is selected based on the following conditions: time of gel formation at the temperature determined for the same zone, which is not less than time of composition pumping to that zone of formation, and initial pressure gradient is higher than depression to which the gel will be subject in the same formation zone.

EFFECT: improving processing quality in the formation zone that is distant from the well working face at simultaneous improvement of preservation period of quality of the installed screen due to reducing the influence of depression on gel-forming composition.

1 ex, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to polyamide-based graft copolymers. Disclosed are graft copolymers based on polyamide which has reacted with a maleic anhydride, containing at least one vinyl-unsaturated side chain, selected from N-vinyl caprolactam and/or N-vinyl pyrrolidone and the polyamide component is at least one compound selected from natural or synthetic polyamides.

EFFECT: disclosed copolymers can be obtained from readily available starting materials using a relatively cheap and simple technique and are suitable for use as gas hydrate inhibitors.

8 cl, 1 tbl, 8 ex

FIELD: production and exploratory well drilling, particularly foaming drilling fluids used during penetration through incompetent rock intervals and during primary productive oil and gas deposit opening in the case of abnormally low formation pressure.

SUBSTANCE: foam composition comprises surfactant, foam stabilizer, water, water hardness control additive and lubricant. The water hardness control additive is sodium silicate. The lubricant is VNIINP-117 emulsion. The foam stabilizer is polyacrylamide, the surfactant is sulphonole. All above components are taken in the following amounts (% by weight): sulphonole - 0.8-1.5, sodium silicate - 0.2-0.5, polyacrylamide - 0.1-0.5, VNIINP-117 - 0.5-2, remainder is water.

EFFECT: reduced power inputs for well drilling, as well as reduced coefficient of friction between drilling tool and well wall.

1 tbl

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