Method for processing underground productive beds

FIELD: oil and gas industry.

SUBSTANCE: method includes injection of processing liquid into bed, which liquid contains solved or dispersed in water complicated ether and polymer destructor, selected from oxidizing destructor and ferment destructor in such a way, that complicated ether is hydrolyzed with production of organic acid for solution of material soluble in acid, present in filtering layer or adjacent to it or in other damage in productive bed, and polymer destructor destroys polymer material, present in filtering layer or bio-film in productive bed.

EFFECT: higher efficiency, simplified method, higher productiveness, higher ecological safety.

31 cl, 1 tbl, 1 ex

 

The method of the present invention is basically applicable to oil, gas or water from wells drilled into underground productive formations.

During drilling operations, processing and production, there are numerous situations when the rate of extraction of oil, gas or water after these operations is limited due to the presence of a breakdown structures. Types of damage include, but are not limited to, the presence containing polymer mud cake, liquids (including destructive hydraulic fluid), or precipitation filtrates, containing polysaccharides including filtration crust, liquid effluents or sludges, materials consisting of particles, such as tools to combat the loss of fluid and rock stuff, biofilms, scales and asphaltenes.

Damage can be near the wellbore, such as the presence of mud cake or damage may be present deeper in the formation, such as natural or induced fractures or skeletal breed.

Effective elimination of damage, in particular damage near the wellbore, such as filtration cortex, can significantly increase the productivity of wells supplying hydrocarbons or water that penetrates the subterranean formation. Effective elimination of damage can also increase the injection capacity of the VCS the new well.

Many years for treatment of injuries in underground formations and stimulation of oil and gas used conventional acid. However, conventional acid have several disadvantages. They quickly react with soluble acid material that can result in poor zone coverage, and they are dangerous to use. To improve zonal coverage, often attempted discharge with high speed, increasing the threat associated with their use. Because of the high corrosivity of the usual acids also typically require the use of corrosion inhibitors. There is a high need for corrosion inhibitors in high-temperature formations, and corrosion inhibitors are usually toxic.

Damage is often caused by a combination of several components. For example, some drilling muds or drilling fluids contain calcium carbonate or dolomite, in combination with the polymer or polymers that provide the appropriate rheological properties. As the carbonate, and the polymer contribute to the formation of mud cake. Carbonate fines generated during the drilling of carbonate rocks may also be present in the filtration crusts.

Mud cake usually contain polysaccharides in high concentrations. In U.S. patent 5247995 cited Paper SPE 21497, the cat is Roy indicated, they can contain up to approximately 48% of the polysaccharide compared to around 4% in destructive fluids.

Mud cake, which do not contain carbonate, may be sensitive to treatment with acid, if present on the surfaces of the wellbore in carbonate formations, as the acid can act on the underlying carbonate and cause the destruction of the mud cake.

The purpose of this invention is to provide a simple and effective way to handle the damage formation in an underground reservoir.

The purpose of this invention is the simple and effective ways effective removal filtration crusts over long horizontal segments.

Another purpose of this invention is to provide a one-step methods in which may be disposed of damage and provides additional stimulation to the performance or rate of discharge by increasing the permeability of the bedrock adjacent undamaged areas of the formation.

An additional purpose of this invention is to provide methods acceptable to the environment, through the use of components with low impact on the environment.

Accordingly, this invention is methods for the treatment of underground reservoir, introducing into the reservoir of the processing liquid containing dissolved or dispersed in water ester and the chopper polymer, so that the ester is hydrolyzed to obtain organic acid to dissolve acid-soluble material present in the reservoir, and the destroyer of the polymer destroys the polymer material present in the reservoir.

The reservoir may be hydrocarbon productive formation, such as gas or oil. Alternative reservoir can be productive water reservoir.

A sufficient number of ester or esters are present in the liquid for processing, so that we obtain a sufficient amount of acid, when the ester is hydrolyzed to obtain a significant effect on the filtration peel or other types of damage. Significant effect implies that a sufficient amount of acid is obtained by hydrolysis of ester to obtain sufficient dissolution of acid-soluble material present in the filtration cork or adjacent thereto, or other damage. For example, the dissolution of carbonate present in the filtration cork, dissolution of carbonate rocks adjacent to the filtration cork or dissolution to rbonate breed, adjacent to the biofilm. To achieve sufficient dissolution requires producirovanie at least a few videosjenny percent acid. The concentration of ester included in the fluid treatment of the present invention will typically be 1% weight/volume, but can be up to 20% weight/volume or higher. In General it was found that 5% to 10% weight/volume of ester when used in combination with a suitable destroyer or suitable destroyers of the polymer are sufficient to obtain good removal of damage caused filtration crust. Preferably be used from 5% to 20% of ester.

It is also assumed that the processing liquid is present a sufficient number of destroyer polymer to provide a significant impact on the present polymeric material. The concentration of the destroyer of the polymer included in the processing fluid will vary according to the type of applied destroyer, but will be of the order of 0.005 to 60 kg/m2preferably from 0.2 to 10 kg/m2.

Basically, it is desirable to use a concentration of destroyer, which leads to the destruction of the polymer during the period of several hours, which enables effective placement of liquid. For example, too fast is atrustee mud cake or biofilms can lead to localized seepage of fluid, oppositely affecting the placement of the fluid to be processed. This is analogous situation arising when processing using conventional acids, when high speed can lead to a rapid breakthrough and fistula and uneven leakage of liquid. This can interfere with the uniform distribution of liquid along the long horizontal intervals or fractures, or rock core rock. A characteristic feature of the processing liquid of the present invention is that the use of ester and not reacting acid, eliminates the formation of fistulas and improves the placement of the liquid. To retain this advantage in some applications, such as handling long horizontal intervals, generally should be excluded too rapid destruction of polymers, for example, in the filtration crusts or biofilms. Ideally, when a breakthrough filtration crusts or biofilms will be achieved after a longer period than the amount of time required for the fluid to be processed. Delay in obtaining significant amounts of acid and destructive polymer enables a uniform impact on the target area and excellent zonal coverage.

The use of ester gives the benefits of effective placement of fluid and eliminating the use of the inhibitor is in corrosion. When you choose the appropriate esters, are used, in particular, esters with low toxicity, high flash point, there are also advantages in terms of safety and the environment. Initially neutral or slightly acidic pH of the liquid allows the inclusion in the liquid such destroyers polymers as enzymes and oxidizing agents, without compatibility issues, take into account, when such agents include drugs with high acidity on the basis of mineral or organic acids.

It is preferable to use agents in the polymer that are activated, or whose activity is increased by changing the conditions, when the ester is hydrolyzed to obtain the acid. For example, the peroxides, which are activated in conditions of high acidity, or enzymes that have activity, increasing with the increase of acidity.

Enzymes suitable as destroyers of polysaccharides usually have a pH optimum in the range from pH 3 to pH 7. Such enzymes will therefore increase their activity with the creation of conditions of moderate acidity arising from the hydrolysis of ester. Creation of conditions of acidic hydrolysis of esters in the presence of acid-soluble material, such as carbonates of calcium or magnesium, results in the it education samovosstanavlivayas buffer. For example, the formation of acetic acid will produce a buffer of acetic acid-acetate or the formation of formic acid buffer of formic acid-formate. If the resulting acid reacts with the acid-soluble material, its quantity will be updated with additional acid formed during the hydrolysis, the remaining predecessor of ester, providing sohranennoi buffer. This can provide ideal conditions for destructive polysaccharides enzymes, resulting in less of the enzyme or enzymes to obtain the same degree of destruction of the polymer compared with the same enzymes, working in conditions of suboptimal pH. Continuous receipt of acid and preservation buffer systems with the method of the present invention, even when the resulting acid reacts with the acid-soluble material, ensures that conditions are favorable pH for the action of the enzyme destroyer supported over an extended period. This contrasts with the case of applying the standard buffer liquids that contain a low concentration of acid, or compounds that generate low concentrations of acids from precursors. In both these cases, the acid will react with the acid-soluble material and will not be replenished. L the specific enzyme destroyers, present in this fluid will work only under favorable pH for a short period of time before the acid used, and the pH becomes more alkaline.

Preferred esters for inclusion in the processing fluid for use in this invention are esters of carboxylic acids with low toxicity, high flash point and high acceptability for the environment. Particularly preferred esters of ethane and methane acids (acetic and formic acid). Calcium and magnesium salts of these acids possess good solubility in water.

Ester should be at least slightly water-soluble. Preferably ester must be soluble in water to at least 1% weight/volume, and most preferably to at least 5%.

The resulting acid according to the method of the present invention is an organic acid, usually aliphatic carboxylic acid. Preferably the acid is of the formula RCO2H, where R is hydrogen, and the alkyl group has from 1 to 6 carbon atoms, or-R'-CO2H, where R' represents a bond or alkilinity group having from 1 to 6 carbon atoms, with the specified alkyl or Allenova group is unsubstituted or substituted with halogen, and the and hydroxyl. Examples include 1,2,3-propanetriol triacetate, 1,2,3-propanetriol diacetate, ethylene glycol diacetate, diethylene glycol diacetate or triethylene glycol diacetate.

When the acid has a hydroxyl Deputy, ester may be cyclic ether complex, such as a lactone.

Alcohol part of ester may be monatomic or polynuclear, because esters are sufficiently water-soluble at temperatures of formation. You can use partial esters of polyhydric alcohols, and in this case, the free hydroxyl groups serve to increase the solubility of ester in the water.

Most preferably, when the esters are esters of acetic acid and 1,2,3-propantriol (glycerine), 1,2-ethanediol (ethylene glycol). The alcohol obtained by hydrolysis of ester, can act as a common solvent. The presence of a common solvent is generally regarded as beneficial in the processing of the load-bearing hydrocarbon formations.

The processing fluid must be locked long enough period of time for formation of the desired amount of acid. Hydrolysis of ester at low temperatures develops slowly. For example, when 10-40°With the hydrolysis may take several weeks. This may be acceptable in some when is Ananiah, such as the removal of mud cake from the borehole, which was drilled and which are locked in for extended periods of time (at least several weeks) before setting in for the kill.

However, it is usually for a more suitable rate of hydrolysis of esters at temperatures below about 120°it is desirable to include in the liquid for processing enzyme. This is done in the usual ways, for example as described in U.S. patent No. 5678632. Lipase, esterase and protease are the preferred enzymes to increase the rate of hydrolysis of ester in the method of this invention.

At temperatures exceeding about 120°With thermal hydrolysis can develop fast enough to be applicable without the need to add gidrolizuemye ester enzyme or enzymes.

In addition to the preferred esters, which should usually include most of the esters present in the compositions of this invention also can be beneficial in some applications to remove the damage to incorporate esters chelating compounds, such as malonic acid, oxalic acid or succinic acid (U.S. patent No. 5082056), ethylenediaminetetraacetic acid (EDTU), Naryshkina acid (NAA), citric acid or guide oxiana acid (U.S. patent No. 5223159), which is hydrolyzed to obtain effective chelating compounds. Such compounds may be particularly useful in the destruction of structured polymers in combination with other polymeric destroyers. Some of the acids obtained from the hydrolysis of ester may be able to dissolve some types of oil crusts. For example, acetic acid can dissolve the calcium sulfate.

Preferred destroyers of the polymers in this invention are oxidizing agents (oxidants) and the enzyme destroyers.

Oxidizing agents used in this invention can be any of oxidative destroyers, known to specialists in this field, which affect the polysaccharides to reduce the viscosity of the gelled polysaccharides compositions or for the destruction of the filtration crusts.

Oxidative destroyer injected into the liquid to be processed containing the component of the complex ester. Oxidative breaker may be present in solution or as a dispersion. Suitable compounds include peroxides, persulfates, perborates, percarbonates, perphosphate, hypochlorites, prsilikat and addition products of hydrogen peroxide, such as the product compounds of urea and hydrogen peroxide and peroxide of magnesium.

Preferred acyclical the mi destroyers for inclusion in the fluid to be processed, used in this invention are peroxides, which can decompose with obtaining hydrogen peroxide. The most preferred oxidizing destroyers are percarbonate and perborate, especially preferred of the most preferred are percarbonate sodium and perborate sodium.

The preferred enzyme destroyers for use in the method of this invention include those destructive polysaccharides enzymes, which, as known in the art suitable for the hydrolysis of polysaccharides and thereby reduce the viscosity of the gelled polysaccharides compositions or destroy mud cake. Enzyme destroyers will be selected based on their known ability to hydrolyze the polysaccharide components that are known or believed to cause damage. Examples of suitable enzymes that can be used for the destruction of the polymers include enzymes that can hydrolyze starch, xanthan gum, cellulose, guar, scleroglucan, succinogenes or derivatives of these polymers.

Oxidative or enzymatic oxidizing agents can also be used for hydrolysis of others, polisaharidnykh polymers that can be included in the liquid for repair of drilling or mining operations.

In some embodiments of this and is gaining efficiency included oxidative destroyers can be improved by more reactive oxidants. Under certain conditions, for example, when in the liquid for treatment include peroxide production hydrogen peroxide in the presence of organic acids can lead to the formation of percolate, which is a more effective oxidant than hydrogen peroxide. The efficiency of obtaining percolate can be increased by incorporating in the composition of some hydrolytic enzymes that can produce percolate of complex air and producing some peroxide hydrogen peroxide United compounds added as oxidants.

Esters, as you know, hydrolyzed by hydrolases (EES), such as a lipase (EC 3.1.1.3), esterase (EC 3.1.1.1) or protease (EC 3,4) in the presence of hydrogen peroxide or other peroxides with the formation of percolate (U.S. patent№№3974082, 5108457, 5296161, 5338474, 5352594, 5364554). Percolate obtained with the help of some enzymes, was used b the purpose of bleaching. Percolate are more effective antioxidants than peroxides, especially at a temperature in the range from 25 to 80°C.

However, percolate are relatively unstable and cannot be used by themselves, but may be formed in place of the peroxide compounds and a suitable precursor of percolate. When esters are present in the composition, the use of lipases is s, Esterhazy or protease enzymes to obtain percolate of complex ether and peroxide is preferable to use a chemically pergidrolevaya predecessors of percolate, such as tetraacetylethylenediamine, which are usually more expensive (for details, see U.S. patent No. 5364554).

If you are using diarylpyrimidine substrate, percolate can be obtained directly by using esterase without the need for hydrogen peroxide.

Other reactions which can be performed directly bleaching compounds present action sulfatase (EU 3,1,6) peroxydisulfate with the formation of peroxymonosulfate (U.S. patent No. 5183473) and the action of the phosphatase (EC 3,1,4) peroxidebased with getting peroxymonosulfate (U.S. patent No. 3666399).

The use of enzymes to obtain percolate in place for treatment of underground formations has not been listed in any of the sources of prior art.

Enzymes with esterase activity, including lipase, esterase and protease, can be used with the method acidification of U.S. patent No. 5678632 and 5813466, but their use to obtain the acids in underground formations described was not. Applicable degree of hydrolysis at temperatures below about 120°usually obtained by using hydrolytic the ski enzymes such as esterase, lipase or protease. The inclusion of peroxide in the processing fluid used in this invention containing such enzymes may therefore lead to the formation of organic acids and perkiset, giving compounds (drugs)that are effective for both acidification and for the destruction of the polymer.

Esters and other chemicals required for the method of the present invention, will usually technical purity to reduce the cost of the process.

When using the enzyme, it is necessary to choose an enzyme that is active in the conditions of the tank and in fluid processing for at least as long as the desired activity of the enzyme.

With the method of the present invention can use two types of enzymes. First of all, it is the enzymes that can destroy the polysaccharide polymers ("enzyme destroyers") and, secondly, it is the enzymes with esterase activity, such as esterase, lipase and protease, which can produce percolate in the presence of hydrogen peroxide. Enzymes of both types usually are water-soluble enzymes. Usually enzymes is the advantage of easy solubility in water, although enzymes can be active and used in an environment with low activity in the water or in two-phase systems, such as emulsions of redisperse. In particular, the lipase may be more active in emulsions.

Usually use the selected enzymes. The enzymes can be isolated from plant, animal, bacterial or fungal sources. The enzymes can be produced by organisms of the wild type, conventional bred, mutant or genetically engineered. Enzymes, optionally, can be chemically modified, because they retain the desired catalytic ability or possess it. Preferably the enzymes are industrial enzymes available for purchase in large quantities from commercial sources.

The processing fluid is prepared in the composition, which reflects the type of the expected damage and conditions of the reservoir, in particular the temperature.

For example, for repairing the damage caused filtration cortex, including calcium carbonate, starch and xanthan gum in the tank at 60°S, can be prepared with the processing liquid containing the composition of an ester of acetic acid esterase and enzymes able to break down the starch and xanthan gum. Esterhazy enzyme added to increase the speed at which hydrolysis of ester according to the method of U.S. patent No. 5678632.

To eliminate damage due to seepage crust containing carbon is tons of calcium, starch and xanthan gum, in the tank at 110°may be prepared in a processing liquid containing an ester of acetic acid and an enzyme able to break down starch. The rate of hydrolysis of ester is usually sufficient, so you can use it at 110°without adding estratega enzyme.

For repairing the damage caused by biofilm, in carbonate formations at 50°may be prepared in a processing liquid containing an ester of acetic acid esterase and a mixture of enzymes able to break down the polysaccharides present in typical biofilms.

For repairing the damage caused by biofilm, in carbonate formations at 80°may be prepared in a processing liquid containing an ester of acetic acid esterase and percarbonate.

It is desirable that all components of a particular manufacturing liquid were compliant or, if not fully compliant, compatible enough to allow a desired amount of acid and the destruction of the polymer during processing. For example, it may be desirable to use a protease to increase the amount of percolate, but the protease may adversely affect some other enzyme, which is present, if such an enzyme sensitive to the action of protease. It will also be necessary to some present enzymes were resistant to any oxidant used in the same composition. Possible problems such as these will be obvious to specialists in this field and will usually be resolved before such compositions will be used in the field.

The processing fluid is usually prepared by dissolving or dispersion of ester and the destroyer of the polymer, optionally with an enzyme that can hydrolyze ester and, optionally peroxide, in a suitable water. Examples include municipal (potable) water, produced water or sea water, although in some situations it may be desirable to introduce undiluted ester or a mixture of ester with a hydrocarbon, such as diesel. Typically, a solution of ester is prepared by a series of barrels or other suitable vessels by the addition of ester to water with stirring and achieve thorough mixing by recirculation of the solution of ester through a mixer, such as a paddle mixer, during the relevant time period. Then add the other components of the liquid for processing and recycling continue. If the manufacturer of the parties is not possible or desirable (for example, if the variance, which is difficult to maintain renominalisation in a large vessel for temporary detention), or if you prefer, the processing liquid can be prepared by adding the individual components to the water continuous, preferably carefully regulated and controlled way, when the liquid is injected into the underground reservoir. Other ways of cooking the selected processing fluids are well known to specialists in this field.

The concentration of ester and material present in the processing liquid will depend on the required number obtained acid and the destroyer.

This will depend on the specific composition of the processing liquid, but will typically be of the order of from 10 to 200 grams per liter of ester and from 0.2 to 10 grams per liter of the other components, although in some situations it may be appropriate higher or lower concentrations. The concentration of any enzyme destroyer will be chosen so that the polymer/gel will break down within a desired period of time. Typical concentrations of the enzyme will be from 0.05% to 5 wt%, available for purchase liquid enzyme products, or from about 0.005% and 0.5% weight. dry preparation of the enzyme. Preferably will be used in liquid preparations of enzymes to facilitate manipulation.

The composition may be included more than one complex ester in chief of the dependence on the nature of the damage formation and type of processing. Also the composition can be included more than one type of destroyer polymers. When the composition of the activated enzyme preparation to obtain percolate in the presence of ester and hydrogen peroxide, may be included more than one enzyme preparation. Preferably use a single solution or dispersion, containing all the components.

In some embodiments of the present invention, it may be desirable to include more than one type of polymer destroyers, for example, could be used oxidant in combination with enzyme destroyer in the case when there are two polysaccharide, but only one can be the action of the enzyme.

Oxidants and enzymes, if desirable, can also be used in the form of drugs with a slow release that will be known to specialists in this field.

The processing fluid containing water ester, the destroyer of the polymer and, if desired, the enzyme is able to hydrolyze ester, usually injected into the subterranean formation through the injection or through wells for production. If the introduction occurs through the newly drilled hole, especially if it is used to remove damage caused during drilling, such as mud cake, the liquid can usually be injected through the drill string from the application of the mud pump. Low corrosiveness of the fluid will give the possibility of introducing into the well or drill string without the need to add corrosion inhibitors. The fluid will usually be injected at a pressure lower than the burst pressure, but if desired, may be introduced and at a pressure above the pressure of the gap.

The processing liquid may contain additional chemical additives such as are commonly used in the oil industry, such as surfactants, foaming and chelating substances, if believe that their inclusion would be beneficial, and if they are compatible with other components of the fluid to be processed.

For treatments near the channel of the borehole fluid volume for processing, are introduced into the tank, is usually equal to at least the channel volume of the well plus the portion on some leakage into the formation. Typically, you would use the volume of liquid in the range between 120% and 200% of the volume of the channel well, though, if you expect a higher degree of fluid loss, can be selected volume up to 300% or higher of the volume of the channel well. As for treatments, when the goal is deeper damage in the formation, such as natural or induced fractures, or grid faults, the volume will be selected according to the requirements of processing.

In one of the embodiments given to the CSOs of the invention can be used amount of the processing liquid, containing both ester and the destroyer of the polymer, which is sufficient to ensure penetration of the liquid to a depth of from one to several meters in carbonate formation around the channel wells or surface fault. This can lead to increased permeability of skeletal carbonate formations to a depth of from one to several meters in addition to the removal of the damaged region near the wellbore or surface faults and at the same time. In such cases, a negative crust can lead to additional productivity well above that which can be achieved even with the complete elimination of damage near the channel well. The volume of liquid required for such treatments will depend on the porosity of the formation, the desired penetration depth and size of the channel wells, fracture or network faults. This approach can also be effective for the treatment of carbonate tight Sandstone reservoirs, which also have damage near the wellbore, again using one-step processing.

The well will normally be locked after the introduction of the processing liquid for a period of typically between 2 hours and a week, preferably onset 6 to 48 hours to provide opportunities acid and destruction polymerasechain then actuate or return to the game, or in the case of injection wells trigger the injection.

This invention has the following special advantages compared with the prior art.

The method is simple, efficient and convenient way to repair the damage caused by the combination of acid-soluble material, and polymers with the use of a single fluid. In particular, this method is one-step treatment that can completely remove the filtration cortex, the reason of which were those fluids for drilling, which contain carbonate as a material from fluid loss and polymers. Previous treatments have been created to remove only the acid-soluble material or polymeric component of such damage.

The method also enables the successful inclusion of oxidative or enzymatic destroyers in the processing fluid, able to create a high concentration of acid. As the acid is present in the form of non-acidic predecessor, the destroyers are not inactivated, as would occur with a lot of contact with conventional acids, and the activity of some destroyers then increases with the occurrence of moderate acidic conditions. This happens after adding fluid, delivering acid and the destroyer, red is necessary.

As for damage near the wellbore or surface fault, the processing liquid may also be used to achieve stimulation of the deep areas of the skeleton of the breed during the same processing. As the fluid is essentially research considers non reactive when placed in place, can be achieved excellent zonal coverage.

In addition, this method is very low-risk way as compared with previous methods, including a significant degree of acidification. When this method is used esters with a high ignition temperature and liquid preparations of enzymes. Basically there is no need for high pressure, high speed injection.

System components are mainly acceptable for the environment. Esters and enzymes and some oxidant components, such as percarbonate have a low impact on the environment. Moreover, these fluids are highly corrosive, which means that usually there is no need for corrosion inhibitors, which offers additional advantages in terms of safety for the environment.

The following example illustrates the invention.

Example 1

Evaluated the effectiveness of a number of machining fluids containing ester, the destroyer of the polymer and, when desirable, ect the time (to increase the rate of hydrolysis of ester or for the production of percolate in the presence of hydrogen peroxide). The liquid was fed to the filtration crusts and rate of water flow through the filtration cortex was measured.

We measured the rate at which water could pass through the disk of filter paper Whatman No. 1 at a negative pressure equal to 30 lb/inch2(206,74 kPa). The disks were damaged by passing drill water based mud containing calcium carbonate, starch and xanthan gum, through the disk until then, until it formed filtration cortex. We measured the rate at which water could pass at a negative pressure in 206,74 kPa. Mud cake is then subjected to a specified processing within the period of 24 hours at the same temperature, and again measured the rate at which water could pass through the disk. The results obtained are shown in table 1.

1. The method of processing damage formation in a subterranean reservoir containing an introduction into the reservoir of the processing liquid containing dissolved or dispersed in water, ester and destroyer polymer selected from the oxidative destroyer and enzyme destroyer so that the ester is hydrolyzed to obtain organic acid to dissolve acid-soluble material present in the filtration cork or adjoining or in the inelastic damage in the reservoir, and the destroyer of the polymer destroys the polymer material present in the filtration cork or biofilm in the reservoir.

2. The method according to p. 1, in which the underground reservoir is a reservoir of hydrocarbons.

3. The method according to p. 2, which further comprises removing from the treated hydrocarbon productive formation.

4. The method according to p. 2 or 3 in which the hydrocarbon is crude oil.

5. The method according to p. 2 or 3, wherein the hydrocarbon is a gas.

6. The method according to p. 1, in which the underground reservoir is a water reservoir.

7. The method according to p. 6, which additionally contains a water extraction from processed underground reservoir.

8. The method according to claim 1, in which the ester is a complex ester of carboxylic acid.

9. The method according to claim 1, in which the ester is a complex ester of aliphatic carboxylic acid of the formula RCO2H, where R represents hydrogen, an alkyl group having from 1 to 6 carbon atoms, or-R'-CO2H, where R' represents a bond or alkilinity group having from 1 to 6 carbon atoms, with the specified alkyl or Allenova group is unsubstituted or substituted with halogen or hydroxyl.

10. The method according to claim 1, in which the ester is a 1,2,3-propane-triol triacetate, 1,2,3-propanetriol diacetate, ethylene glycol diacetate, di is etilenglikola diacetate or triethylene glycol diacetate.

11. The method according to claim 1, in which the concentration of ester in the liquid to be processed is at least about 5% weight/volume.

12. The method according to p. 1, in which the enzyme destroyer polymer is gidrolizny enzyme.

13. The method according to claim 1, wherein the enzyme breaker polymer is gidrolizuemye polysaccharide enzyme.

14. The method according to any one of the preceding paragraphs, in which the enzyme destroyer polymer is an enzyme that can hydrolyze starch, xanthan gum, cellulose, guar, scleroglucan or actinolite, or a derivative of any one of these polymers.

15. The method according to claim 1, in which oxidative destroyer polymer is an oxidant selected from persulfate, sodium hypochlorite, peroxide, perborate, percarbonate, perphosphate, perserikatan and product attach a metal cation or hydrogen peroxide.

16. The method according to claim 1, in which oxidative destroyer polymer is an oxidant in the form of the drug with a slow release.

17. The method according to claim 1, in which the processing liquid further comprises an enzyme able to hydrolyze ester.

18. The method according to claim 1, wherein the processing liquid contains peroxide.

19. The method according to 17, wherein said enzyme is a lipase, stiasny or proteiny enzyme.

20. The method according to p, in which peroxide is perborates or percarbonates.

21. The method according to claim 1, in which the temperature of the formation, bearing acid-soluble material and a polymeric material, at least equal to, 4°C or higher.

22. The method according to claim 1, in which the processing fluid left in the reservoir for at least 1 hour

23. The method according to claim 1, in which the processing fluid is injected into the reservoir through the wellbore, which takes place in the reservoir.

24. The method according to p. 23, in which the wellbore is vertical, deviated, inclined or horizontal.

25. The method according to any one of claims 1 to 24, in which the processing fluid is injected into the producing formation through the drill string.

26. The method according to claim 1, in which the processing fluid is injected into the reservoir through the spirally rolled up the pipeline.

27. The method according to p. 1, in which the processing fluid is injected into the reservoir through a pipeline with a rounded head.

28. The method according to 17, in which each enzyme is in the form of a drug with a slow release.

29. The method according to claim 1, in which the processing fluid is injected to lower the burst pressure of the productive formation.

30. The method according to claim 1, in which the processing fluid is injected to the extent higher burst pressure productive the Lasta.

31. The method according to claim 1, in which the reservoir is or includes a carbonate rock.



 

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1 ex, 1 tbl

FIELD: oil recovery industry, in particular buildup of reservoir recovery of low permeable, clay-containing beds.

SUBSTANCE: declaying composition contains clay dispersing reagent, peroxide compound and water, wherein as peroxide compound potassium fluoride peroxysolvate in activated form, comprising 1-3 mass % of oxalic or salicylic acid; and includes two sequential technological solutions. More specifically claimed composition contains (mass %): technological solutions 1: potassium fluoride peroxysolvate 1-2.5; hydrochloric acid as clay dispersing reagent 3-8.0; and balance: water; technological solutions 2: potassium fluoride peroxysolvate 1-2.5; sodium hydroxide as clay dispersing reagent 4-6.0; and balance: water. In addition said solution contain 0.1-1.0 mass % of water soluble surfactant. After treatment with disclosed solutions and well exposure dispersed reaction products are removed from bottom-hole formation zone.

EFFECT: bottom-hole formation zone of improved permeability due to effective removing of clayish and other mudding materials.

3 cl, 19 ex, 3 tbl

FIELD: oil and gas production.

SUBSTANCE: invention provides composition that can be used to intensify oil inflow and to develop well by means of acid treatment of terrigenous oil reservoir as well as to intensify oil inflow and to increase oil recovery of formations with the aid of hydraulic rupture of formation assisted by acid solutions. Composition contains borohydrofluoric acid needed to create borosilicate films prohibiting migration of particles during acid treatment. In addition, composition is characterized by lowered rate of reaction with rock at formation temperature in order to extend coverage of formation by treatment and to diminish deposit formation risk, low surface tension, low corrosion rate, and compatibility with inhibitors added to commercial acid, which will enhance efficiency of acid treatment using composition of invention. Composition is made up of, wt %: inhibited hydrochloric acid 8.0-15.0, fluorine-containing reagent (hydrofluoric acid, ammonium bifluoride, or ammonium fluoride) 1.5-10.0, boric acid 1.0-3.0, additionally isopropyl alcohol 5.0-10.0, and "Alkylfosfat-Khimeko" or "Efiroks-7", or "Fosfol-10" 0.5-2.0, and fresh water to 100%. In a method of acid treatment of the bottom area of terrigenous formation comprising consecutively pumping flushing fluid and acid composition into borehole, forcing the latter into formation by the aid of flushing fluid, giving time (up to 8 h) for reaction and subsequent removal of reaction products. Acid composition is used as it is or in the form of aqueous solution obtained by diluting composition with fresh water at water-to-composition ratio (1-5):1 in amount corresponding to 0.5-2.0 m3 per 1 m of perforated thickness of the formation. As flushing fluid, 1.5-3.0% ammonium chloride solution is used in amount 0.5-1.5 m3/m before pumping of acid composition or in amount 1.0-5.0 m3/m when used to force acid composition.

EFFECT: expanded useful possibilities of acid composition.

2 cl, 1 dwg, 2 tbl, 4 ex

FIELD: oil and gas production.

SUBSTANCE: invention relates to compositions used for intensifying wells owing to increasing permeability of rocks forming well bottom zones. Composition of invention contains 7.0 to 30.0% ethanol, 0.1 to 0.3% cupric chloride, 0.1 to 0.5% alkylbenzenesulfonate, and trichloroacetic acid (to 100%).

EFFECT: increased dissolving capacity of composition with respect to asphaltene-tar and paraffin deposits filling crack and pore space of rocks forming well bottom zones.

1 tbl

FIELD: oil and gas extractive industry.

SUBSTANCE: device has pipe-like body with detachable upper and lower sleeves. Concentrically to body, with possible rotation relatively to it, a cover is mounted with blades with scrapers placed spirally on its surface. To lower sleeve a reactive end piece is connected with slit apertures. End piece hollow is filled with granulated material engaging in exothermal reaction with acid. Lower portion of end piece is provided with check valve. Upper sleeve is provided with check valve having locking element in form of sphere with shelf and centering elements, to be dropped from well mouth. Base of saddle of check valve is made in form of disc having diameter equal to diameter of body. Pass aperture of saddle in lower portion is overlapped with easily destructible and easily removed element. Length of sphere shelf is greater than height of pass aperture of saddle of check valve of upper sleeve.

EFFECT: higher reliability, higher efficiency, broader functional capabilities of device.

3 cl, 4 dwg, 1 tbl

FIELD: oil and gas production.

SUBSTANCE: invention aims at increasing productivity of oil- and gas-producing and injecting wells exposing high-temperature low-permeable oil reservoirs. In the treatment method according to invention including forcing enzyme substrate and separate enzyme into formation and creating conditions to enzymatically convert substrate into acid, geologic and productive characteristics for each interval of bottom zone are determined in order to pick out low-permeable intervals of oil reservoir for treatment, whereupon properties of enzyme substrate and separate enzyme as well as conditions for their pumping are chosen. Substrate utilized in the method is head fraction of methyl- and/or ethyl-, and/or butyl acetate production, to which aliphatic alcohols are added, and enzyme is an acid solution. Substrate is pumped simultaneously and/or before, and/or after pumping of enzyme, after which well is closed for some time and then opened and placed under predetermined operational conditions.

EFFECT: enhanced efficiency of acid treatment due to increased phase permeability for oil and deepness of active acid-treated zone of low-permeable oil reservoirs.

25 cl, 1 tbl, 3 ex

The invention relates to the oil industry, in particular to compositions and methods acid treatment of bottom-hole zone of terrigenous reservoir, and can be used in the process of stimulation of oil and exploration wells by acid treatment of terrigenous reservoir, as well as for the stimulation of oil and improve the oil recovery method of hydraulic fracturing using acid solutions

FIELD: oil and gas extractive industry.

SUBSTANCE: method includes examination of operation well for gas-condensation and periodical cleaning of face-adjacent well area from precipitating hydrocarbon condensate by pumping hydrocarbon condensate solvent into bed, exposure of well for period of condensate dissolution and following removal of received solution from face-adjacent area during well launch, as solvent binary mixture is used with unlimited mutual solubility of components, while at least one of them has unlimited mutual solubility with hydrocarbon condensate, and relation of binary mixture components is determined from previously built phase diagram of three-component system, formed during dissolution of hydrocarbon condensate. As binary mixture with unlimited mutual solubility of components a mixture of acetone and methanol is used, or chloroform and methanol, or chloroform and aniline, or chloroform and acetone.

EFFECT: higher productiveness.

2 cl, 3 ex, 6 tbl, 2 dwg

FIELD: oil extractive industry.

SUBSTANCE: compound includes organic acidic reagent and cubic remains of amine production C17-C20, and as organic acidic reagent contains sulphamine acid with following ratio of components in percents of mass: sulphamine acid 20-70, C17-C20 the rest or mixture of sulphamine acid with nitriletetramethylphosphone acid with following ratio of components in percents of mass: sulphamine acid 10-40, nitriletetramethylphosphone acid 25-70, C17-C20 the rest.

EFFECT: higher efficiency.

2 ex, 7 tbl

FIELD: oil and gas production and corrosion protection.

SUBSTANCE: composition according to invention, which can be used for asphaltene-tar-paraffin deposits from bottom zone of formation, discharge pipes, oil-collection reservoirs, and oil-field equipment, contains 1-5 vol % nonionic surfactant: oleic acid, С912-alkyl-phenol, С910-alkyl-phenol, or N-alkyl-3-methyl-5-ethylpyridinum bromide in solvent; 1-5% cationic surfactant: product of reaction of primary and secondary aliphatic amine mixture with industrial-grade dimethyl phosphite; and solvent (Absorbent A) in balancing amount. Composition can also be based on straight-run gasoline containing in this case 10 to 50 vol % Absorbent A.

EFFECT: increased cleaning efficiency in combination with anticorrosive effect and reduced expenses on reagents.

2 cl, 3 tbl, 23 ex

FIELD: oil and gas production.

SUBSTANCE: invention is intended to protect inner surface of transmission pipelines against asphalt-tar-paraffin deposits and provides appropriate composition containing 0.5-10% polyvinyl alcohol, 0.01-1% nonionic surfactant (FK 2000 PLUS), and water.

EFFECT: prolonged pipeline protection effect of composition and manifested demulsification activity.

1 dwg, 5 tbl, 5 ex

The invention relates to the oil industry and can be used for dispensing reagents into the well and flow line

The invention relates to the field of oil production and is intended for cleaning of wells from asphaltene-resin and paraffin-hydrate deposits (ASPHO) generated during operation of wells

Dosing installation // 2238393
The invention relates to the oil industry and can be used for the dosing of liquid inhibitors in oil wells, technological and trunk water and pipelines

The invention relates to the field of oil production, in particular to solid reagents to prevent sediment asphaltene-maloperation substances (ASPV) in the extraction and transport of oil

The invention relates to the oil industry, in particular to methods for processing bottom-hole zone of the production well or wells, translated in the discharge of mining, which is complicated by the loss of asphaltoresinparaffin substances (ASPO) in the critical zone

The invention relates to the production of oil, namely, to prevent the deposition of mineral salts and iron sulfide in wells and oilfield equipment

FIELD: oil and gas production.

SUBSTANCE: invention is intended to protect inner surface of transmission pipelines against asphalt-tar-paraffin deposits and provides appropriate composition containing 0.5-10% polyvinyl alcohol, 0.01-1% nonionic surfactant (FK 2000 PLUS), and water.

EFFECT: prolonged pipeline protection effect of composition and manifested demulsification activity.

1 dwg, 5 tbl, 5 ex

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