Method of treating bottom zone of low-permeable oil reservoirs

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 and gas industry, in particular, to improving the performance of oil and gas production and injection wells that discover high-temperature low-permeability reservoirs.

A method of processing bottom-hole formation zone in which the layer sequentially fetch buffer liquid hydrocarbon-based, representing a mixture of gasoline and isopropyl alcohol, an aqueous solution of hydrochloric acid or glyoxylate in a mixture with the alcohol and the second buffer fluid, which use gasoline containing a mixture of saturated hydrocarbons from C3and above, after which the well is left on the reaction, and then master compressor (RF patent No. 2042807, E 21 In 43/27, 1995).

The disadvantage of this method is low, the impact on low-permeability reservoirs, as used buffer liquid hydrocarbon-based slightly improve the filtering conditions in the reservoir for acid composition, inconsequential slow down the speed of reaction of the acid with rock at temperatures from 90°and above and are not effectively removed from the treated area are the reaction products of the acid with rock.

A method of processing bottom-hole zone of high-temperature low-permeability sand-shale reservoirs Jurassic deposits Latitudes the CSOs Ob, includes consistently the injection buffer liquid, reagent and buffer fluid. As the buffer fluid using a mutual solvent (patent RF №2187634, E 21 In 43/27, 2002).

The disadvantage of this method of processing is its low impact on the formation associated with reduced depth of the treated area of the active acid.

The closest in technical essence to the proposed solution is the way the acid treatment of subterranean formations, which consists in forcing into the formation of the substrate for the enzyme and a separate enzyme and the conversion of the substrate in the organic acid under the action of the enzyme (patent RF №2122633, E 21 In 43/27, 37/06, With 12 N 9/20, 1998).

The disadvantage of this method the acid treatment is that the substrate and the enzyme is soluble in water and insoluble in hydrocarbons. Therefore, when injected into a reservoir in the form of aqueous solutions are filtered, mainly in water-saturated formation, which leads, ultimately, to increase the relative permeability for water, and permeability of oil with virtually no changes. Thus, this method of treatment allows to intensify the work in more injection wells than mining.

The technical result of the present invention is to increase the efficiency of acid is based processing due to the increase in the relative permeability to oil and depth of the treated area low-permeability reservoirs active acid.

The technical result is achieved in that in the processing method of the bottomhole zone of low permeability reservoirs, including injection into the reservoir substrate for the enzyme and a separate enzyme, creating conditions for the conversion of the substrate in an acid under the action of the enzyme, for each interval bottomhole determine its geologic characteristics, which emit low-permeability reservoir intervals to process and choose properties of the substrate for the enzyme and a separate enzyme, as well as the mode of injection, as the substrate used head fraction of methyl and/or ethyl-, and/or butylacetate production with the addition of aliphatic alcohols uglevodorodyonogo and as enzyme - acid composition, and the substrate is injected simultaneously and/or before and/or after injection of the enzyme, then shut the well in for a certain time, after which her master and output for a given operation.

To improve the efficiency of the method specified in addition to the main solution can be further used in one or more of the following technical solutions.

According to the results of geophysical, and/or hydrodynamic, and/or physico-chemical studies define the geologic characteristics of the intervals of critical areas - power, saturation, posovietiniame for reservoir fluids and the change in permeability along the radius of the zones, type of mudding - iron sulfides (FeS), the asphalt-resin-paraffin deposits (ARPD), oxidized and thickened petroleum products (OSN), particle species (SiO2; Caso3; Na4Al2Si2O9), iron oxides (Fe2About3; Fe3O4items biosurgery (SSC).

Choose intervals with reduced man-caused by phase permeability for the hydrocarbons produced and/or injected water and/or intervals with increased saturation of hydrocarbons, isolating other intervals packers, and/or buffer fluids, and/or a blocking structure, optimizing the flow profile or pickup.

As properties uglevodorodyonogo substrate for the enzyme and a separate enzyme used their composition, volume and concentration, providing the highest decommutation low-permeability intervals in situ, and/or increased permeability of the hydrocarbon-producing wells, and/or increasing the relative permeability for water injected into the injection wells.

Select and adjust properties uglevodorodyonogo substrate and thermobaric regime injecting into an area of low permeability, depending on the geological and physical properties of formation, physical and chemical properties of reservoir fluids, the type of plugging dynamics and changes in the technological regime of the well.

Determine the mode of injection and the time response of the substrate for the enzyme and a separate enzyme on the rate of formation of organic acids in the reservoir with respect to temperature of the reservoir and the concentration of acidic composition.

The head fraction of methyl and/or ethyl-, and/or butylacetate production contains esters of carboxylic acids, ethers, and aldehydes, and esters of carboxylic acids are methyl and ethyl formate, methyl and/or ethyl and/or butyl acetate.

As aliphatic alcohols using methanol and/or ethanol and/or isopropanol.

Use a mixture of head fraction of methyl and/or ethyl-, and/or butylacetate production and aliphatic alcohols in the ratio of 5.5 to 6:1.

The substrate forms formic and/or acetic acid in low-permeability and/or kolmat part of the bottomhole zone.

As acidic composition for treatment of low-permeability carbonate reservoirs using hydrochloric acid, and for the processing of low-permeability Sandstone reservoirs using pinacolato.

Acid composition into the formation with the substrate at a ratio of 1:10-15 when the concentration of the acid 16-24%.

Download the substrate and the enzyme through a vertical or horizontal wellbore in the reservoir or in certain intervals of the formation, which in the latter case, isolated on the ug from each other packer sections and/or inert buffer liquids.

In the layer of pre-fetch composition, blocking high permeability intervals, as such, use of oil-water emulsion.

In the hole previously injected inert buffer liquid with a density of greater or lesser density uglevodorodyonogo substrate.

The well is closed for 2-24 hours under pressure to respond in accordance with the rate of formation of organic acids and scope of the impact along the strike of the bottomhole zone of the formation.

The well is completed directly after processing without intermediate damping to change the layout and make it a given technological regime, creating optimal conditions for removal from the reservoir or displacement into the formation plugging of the processed substrate and the enzyme zone.

During the development choose the bottomhole pressure and rate of its change, recording the dynamics of the buffer and annulus pressure and the change in dynamic level and physical-chemical properties of produced fluids, gradually or sharply reducing the bottomhole pressure to the most complete removal products clogging of the bottom zone, after which establish and maintain the technological regime of the well at the level of warning induced decrease the permeability zone and/or maximizing production at the of leogardo for a specified period of time.

Set the specified process mode wells, record the dynamics of the parameters of the technological regime and physico-chemical properties of produced fluids and rejecting their values beyond the established boundaries of the re-make treatment of bottom-hole zone and/or modify the operation of the wells in such a way as to ensure maximum production of hydrocarbons.

Set the given mode of injection water injection wells, register the dynamics of technological parameters of injection modes, and when the deviation of their values beyond the established boundaries of the re-make treatment of bottom-hole zone and/or modify the operation of the wells in such a way as to provide the specified pressure and/or a predetermined acceleration and/or maximum coverage of the formation water.

The injection of substrate and enzyme continued and/or repeated to ensure the required capacity of the zone of influence of the substrate and the enzyme and/or oil under specified temperature and pressure conditions.

Immediately upon injection of substrate and enzyme in the bottomhole zone of low permeability interval of the reservoir effect on other intervals of this well and/or reduce the maximum bottom-hole pressure in the associated production wells, and/or stop for a while about what Abadi water injection into injection wells.

During and/or after the injection of substrate and enzyme in the formation he is under the influence of heat and/or depressions and/or repression, and/or acoustic and/or electromagnetic and/or vibro-seismic vibrations.

Geologic characteristics (permeability) of each interval of the bottomhole zone are determined by the results of photocamera and/or thermometry.

The flow of oil from the reservoir to the bottom wells is difficult because of the formation in the bottom part of the man-made radial zone of high water saturation, blocking the flow of oil. The formation of this zone of high water saturation associated with the penetration into the formation water during drilling and cementing wells at the opening of the reservoir and killing it for other processing or repair operations in the well, and when well water from aquifers and high-permeability zones of the reservoir. The water is filtered in a layer of clay mud or fluid damping, presses the oil from the bottom part of the depth of the reservoir and is held in the pores by capillary forces. Further during the development of oil wells is often not able to overcome the capillary pressure, water retention in the low permeability of the reservoir, and is filtered only by the high permeability zone of the formation, and riscoprono EMA remains uncovered by the flooding.

In the hydrophilic rock pressure arising at the interface of oil-water in the pores, holds water in a porous medium. But, if the surface of a solid body, i.e. of rock particles, process gidrofobiziruyuschimi substances, it becomes water-repellent property and capillary pressure changes its sign on the reverse, i.e. it displaces water out of the capillary. This means that in the bottomhole formation zone water is displaced by the oil from the fine pores in the major, of which she later during the development wells can be easily removed.

Features rock sand and shale reservoirs contribute significant limitations in the application of methods of acidizing associated with the use of liquids is water-based. Thus, the reservoirs contain a low percentage of soluble acid components and their high clay content creates the preconditions for the reduction of permeability due to clay swelling in the aquatic environment. High water retention leads to the fact that if water is present in the bottomhole formation zone forms a stable barrier that dramatically reduces permeability rocks for oil. In General, the negative impact of water significantly reduces the effectiveness of the work, and in some cases reduces the efficiency to zero.

Substrate - head fraction of methyl and/or ethyl-, and/or Buti the acetate production (allylacetate) with the addition of aliphatic alcohols in a ratio of 5.5 to 6:1 (vol.) soluble in hydrocarbons and partially soluble in water. During injection into the reservoir to the production well, the substrate is filtered, mainly in the oil-bearing formation, purifying thus the treated pores and channels filtering of high-molecular compounds (film of oil and resinous, asphaltenes, paraffin deposits).

Water-soluble aliphatic alcohol contained in the substrate, removes the water held by capillary forces from the porous medium and reduces the saturation in the low permeability of the reservoir, blocking the flow of oil.

The use of the substrate reduces the interfacial surface tension of aqueous solutions on the border with hydrocarbons up to scratch, creating a homogeneous system with contact and mixing reservoir and injected fluids, i.e. prevents the formation of water-oil emulsions, blocking the channels of the filter.

In addition, the substrate has gidrofobiziruyuschimi properties in relation to the formation rock. Upon contact of the substrate with the reservoir rock due to the reaction between the carboxyl group of esters of carboxylic acids and hydroxyl groups of minerals is the adsorption of the substrate to the surface of the rock and is formed on the surface rigidly connected monomolecular film having water-repellent properties.

All of the above factors in aggravation of the substrate p. the AST result in higher permeabilities for oil and improve the filtering conditions in the low permeability zones of the formation of acidic composition, injected after the substrate.

The substrate is injected with the enzyme at the same time and/or before and/or after injection of the enzyme, the mixture is soluble in hydrocarbons and sparingly soluble in water, therefore, is filtered, mainly in oil-saturated layers, as previously uploaded substrate. In addition to the above positive action of the substrate, in a mixture with the substrate decreases the activity of acid and speed of interaction of the acid with rock. This allows, firstly, to promote active acid at a greater distance from the borehole, that is, to increase the depth of the treated area, and secondly, to slow secondary Sadko and gelation of the reaction products. This is especially important in the conditions of a temperature of more than 80°in which salt, especially hydrofluoric acid in the usual aqueous solutions spent on interaction with the breed in several minutes from the beginning of contact.

It is known that to achieve significant improvements in the productivity of wells necessary to increase the permeability of the reservoir, extending at least 3 meters from the borehole, which cannot be achieved only by the slow reaction of the acid with the breed.

In the present invention the composition of the substrate comprises esters of carboxylic acids: methylformate, ethyl formate, ethyl acetate, b is tracecut. In situ in the presence of acids is their hydrolysis with the formation of water-soluble organic acids (formic, acetic) and alcohols (methanol, ethanol, butanol).

For example, in the hydrolysis of ethyl acetate produces acetic acid and ethanol by the reaction:

CH3SOOS2H5+H2O---→CH3COOH+C2H5HE

Acetic acid reacts with the carbonate rock:

2CH3COOH+caso3---→Sa(CH3Soo)2+H2O+CO2

The resulting acid (formic, acetic) also dissolve iron deposits and corrosion products (oxides and hydroxides of iron).

A byproduct of the conversion of ester are alcohols, which reduce the surface tension between oil and water and reduce the hydration of the clay material, thereby facilitating their removal from the reservoir when the call flow and accelerating the cleanout from mechanical impurities (i.e. there is a clay formation removal of the reservoir).

Acid composition with the substrate penetrates deeply into the formation prior to the formation of acid. Organic acids begin to form over time from several hours to several days, and the rate of formation of the acid depends on the concentration of acid composition and reservoir temperature, with increasing concentration of acid composition and the temperature of the reservoir, the rate of formation of organic acids increases.

For processing sand and shale reservoirs as acid composition is used glyoxylate, dissolving silicate cementitious material reservoir rock (clay, claystone, amorphous kremachoclet).

Thus, the acid composition with the substrate can be deeply injected into the formation around the wellbore prior to the formation of organic acids and carbonate dissolution or sandy-argillaceous rocks, leading, ultimately, to increase the permeability of the treated formation in a much wider area around the wellbore and along cracks than salt or glyoxylate, including with slow reaction rate, which goes directly near the wellbore or surface cracks.

Acid composition with the substrate is not corrosive than hydrochloric or pinacolato formed formic and acetic acid does not corrode steel, chromium and aluminum hardware.

For intensification of horizontal wells salt or pinacolato requires the use of special techniques to prevent corrosion of underground equipment and prevent consumption of acid until it reaches the far end of the horizontal wells.

The proposed sequential injection is not corrosive substrate and acid composition with what stratum allows you to increase the productivity of horizontal wells by removing drill cuttings and sediments, as well as due to the formation of acid along the entire length of the horizontal well.

Subsequent injection of the substrate after acid composition with the substrate helps to remove the water introduced into the bottom zone of the acid composition, which is especially important in low-permeable hydrophilic seal off the reservoir. In addition, by reducing the surface tension at the boundary of fluids and injected into the layer of reagent improves the conditions of carrying out of the treatment area of waste chemicals, rychlovarnou produced water, as well as reaction products and fine solid particles.

All reagents used in the present method, are produced by the domestic industry:

head a fraction of the ethyl - and/or butylacetate production;

hydrochloric acid THE technical 6-01-714-77;

hydrofluoric acid GOST 48-5-184-78;

methanol GOST 6995-77;

ethanol GOST 18300-72;

isopropanol TU 6-09-402-75.

In terms of the well, the method is as follows. Identify low-permeability reservoir intervals according to photocamera and/or thermometry and first of all intervals, reducing its permeability by natural causes. This compares permeability for remote and close to the borehole zone, obtained, for example, based on hydrodynamic studies (curves restored the I pressure, indicator curves).

Then through down to the perforated interval of the tubing with the packer or without a packer in low-permeability interval (intervals) bottom-hole formation zone download the substrate at the rate of 0.5-1 m31 m perforated interval of the formation. Behind him in the bottomhole zone of injected acid composition with the substrate at the rate of 0.3-0.5 m by 1 m of the perforation interval, which is forced into the reservoir substrate at the rate of 0.5-1 m31 m perforated interval. Shut the well in response to 2-24 hours and learn the well swab, a fountain, gas lift or pump away from it, the liquid in excess of 2-3 times the volume injected into the layer of substrate and enzyme.

This method can also be used when bespothadnoj technologies for intensification as production and injection wells, in particular, to align the flow profile and pickup. Because pumped reagent petroleum based its permeability in a more high-permeability intervals, washed with water, not proportional to absolute permeability, and the share of net oil pay (at a later stage in the development of low-permeability reservoirs not covered by impact) collectors in the pick-up will be more than water-saturated reservoirs. This selection is I the ability of the reagent, on the one hand, allows to increase permeability for hydrocarbons in producing wells, on the other hand, leads to an increase in injectivity is not covered by the flooding of the reservoir intervals in the injection well.

The effectiveness of the proposed method is confirmed by laboratory tests.

Example 1.

Through the vertical column of quartz sand fraction 0,315-0,630 mm was filtered produced water with a bulk velocity 0,362 l/h, then kerosene, the volumetric rate of which was 0,0232 l/h. After this was filtered sequentially 1,5 held pore volume (V then.) the substrate head of an ethyl acetate fraction of production GFAP with the addition of ethanol (ethyl GFAP) in the ratio of 5.5:1 (by vol.), substrate (GFAP with dobavki ethanol) and glyoxylate in the ratio of 10:1 (vol.) and again, the specified substrate with a bulk velocity of 0.80 l/h. Then through the column missed again kerosene, volume filtration rate which was 0,427 l/h. Comparing the values of the volumetric velocity filtering kerosene before and after injection of the indicated substrate, it is seen that after the injection of a specified substrate filtration rate of kerosene increased by 18.4 times.

Example 2.

Analogously to example 1 in the same sequence injected produced water, kerosene and 0.5 V then. GFAP with the addition of ethanol, GFAP with d is the additive ethanol and pinacolato, GFAP with the addition of ethanol and re-fuel. The volumetric rate of filtration of kerosene after injection of the indicated substrate increased 6.4 times.

Example 3.

Analogously to example 1 in the same sequence injected produced water, kerosene and 0.16 V then. GFAP with the addition of ethanol, GFAP with the addition of ethanol and pinacolato, GFAP with the addition of ethanol and re-fuel. The volumetric rate of filtration of kerosene after injection of the indicated substrate increased 3.2 times, however, when pumping of 0.5 V then. kerosene after the specified substrate him volumetric filtration rate decreased to the initial value.

Analogously to example 1 were carried out studies on the filter substrate - GFAP with the addition of methanol and isopropanol, as well as substrate - head of the faction butylacetate production (GFBP) with the addition of various alcohols. The research results are summarized in the table.

Table
SubstrateAlcoholEnzymeV porzycki alcohol substrate to the enzymeThe fold increase in flow rate filtration kerosene
GFAPmethanolpinacolato1,519,2
-"-0,5 6,9
-"-0,163,3
ethanol1,518,4
-"-0,56,4
-"-0,163,2
isopropanol1,516,5
-"-0,56,0
-"-0,162,7
GFBPmethanolpinacolato1,514,7
-"-0,55,3
-"-0,162,9
ethanol1,514,2
-"-0,5a 4.9
-"-0,162,3
isopropanol1,5to 12.0
-"-0,53,7
-"-0,161,9

To implement the method can also be used in the following cases injection of substrate:

1) with the enzyme at the same time and after injection of the enzyme with the substrate;

2) with the enzyme at the same time;

3) after injection of the enzyme;

4) before and after injection of the enzyme;

5) prior to injection of the enzyme.

The efficacy of these cases, the zoom ratio is the volume of filtration rate of kerosene respectively for cases 5,1; 5,3; 4,6; the 5.7 and 4.9. At the same time as substrate was used head the fraction of an ethyl acetate production with the addition of methanol, and the enzyme - glyoxylate, and the pore volume injection of substrate with the enzyme was 0.5.

The efficiency of processing bottom-hole formation zone of the SCR using the technology of the present invention are also tested for two specific wells Nivagalskoe field, revealing the low-permeability layer of SE-1. Well No. 2248, with an initial flow rate of the liquid 8 m3/day, the water content of 29%, after OPZ liquid flow increased to 18 m3/day, and the water content is reduced to 20%. Well No. 2113 with an initial flow rate of the fluid 6 m3/day, the water content of 43%, after OPZ liquid flow increased to 13 m3/day, and the water content decreased to 36%.

Evaluation of the effectiveness of the technological processing bottom-hole formation zone of the SCR using the technology according to the invention was carried out by comparing the actual and basic characteristics of oil displacement by water (the dependence of the accumulated oil from the accumulated liquid production). This basic characteristic displacement was obtained by the most accurate and versatile four-parameter model (Leonov, C. A. Method of adaptive optimization in reservoir pressure. NPK “the Newest methods of increasing n is teotwaki layers - theory and practice”. Kazan, 2001). The result is compared with the baseline within six months after the bottomhole zone treatment according to the invention, the accumulated production of liquids increased by 2.7 thousand tons, and the cumulative oil production increased by 1.9 thousand tons.

1. The processing method of the bottomhole zone of low permeability reservoirs, including injection into the reservoir substrate for the enzyme and a separate enzyme, creating conditions for the conversion of the substrate in an acid under the action of the enzyme, characterized in that for each interval bottomhole determine its geologic characteristics, which emit low-permeability reservoir intervals to process and choose properties of the substrate for the enzyme and a separate enzyme, as well as the mode of injection, as the substrate used head fraction of methyl and/or ethyl-, and/or butylacetate production with the addition of aliphatic alcohols uglevodorodyonogo, as well as enzyme - acid composition, and the substrate is injected simultaneously and/or before and/or after injection of the enzyme, then shut the well in for a certain time, after which her master and output for a given operation.

2. The method according to claim 1, characterized in that the results of geophysical, and/or hydrodynamic, and/or physico-chemical studies describe a geologist who-commercial specifications intervals of critical areas - the power saturation, the relative permeability for reservoir fluids and the change in permeability along the radius of the zones, the type of mudding - iron sulfides, asfaltosmesitelnye deposits of paraffin, oxidized and thickened oil OSN, particles of rock, iron oxide Fe2O3,Fe3O4products biosurgery.

3. The method according to claim 1, characterized in that the chosen intervals with reduced man-caused by phase permeability for the hydrocarbons produced and/or injected water and/or intervals with increased saturation of hydrocarbons, isolating other intervals packers, and/or buffer fluids, and/or a blocking structure, optimizing the flow profile or pickup.

4. The method according to claim 1, characterized in that as properties uglevodorodyonogo substrate for the enzyme and a separate enzyme used their composition, volume and concentration, providing the highest decommutation low-permeability intervals in situ, and/or increased permeability of the hydrocarbon-producing wells, and/or increasing the relative permeability for water injected into the injection wells.

5. The method according to claim 1, characterized in that select and adjust properties uglevodorodyonogo substrate and thermobaric regime for its injection into the area with irennoj permeability depending on the geological characteristics of the reservoir, physico-chemical properties of reservoir fluids, the type of plugging and dynamics of changes in the technological regime of the well.

6. The method according to claim 1, characterized in that determine the mode of injection and the time response of the substrate for the enzyme and a separate enzyme on the rate of formation of organic acids in the reservoir with respect to temperature of the reservoir and the concentration of acidic composition.

7. The method according to claim 1, characterized in that the head fraction of methyl and/or ethyl-, and/or butylacetate production contains esters of carboxylic acids, ethers, and aldehydes.

8. The method according to claim 1 or 7, characterized in that esters of carboxylic acids are methyl and ethyl formate, methyl and/or ethyl and/or butyl acetate.

9. The method according to claim 1, characterized in that aliphatic alcohols using methanol and/or ethanol and/or isopropanol.

10. The method according to claim 1, characterized in that a mixture of head fraction of methyl and/or ethyl-, and/or butylacetate production and aliphatic alcohols in the ratio of 5.5 to 6:1.

11. The method according to claim 1, characterized in that the substrate forms formic and/or acetic acid in low-permeability and/or kolmat part of the bottomhole zone.

12. The method according to claim 1, characterized in that the acidic composition for treatment of low-permeability carbonate reservoirs using the hydrochloric acid, and for the processing of low-permeability Sandstone reservoirs using pinacolato.

13. The method according to PP. 1 and 11, characterized in that the acid composition into the formation with the substrate at a ratio of 1:10-15 when the concentration of the acid 16-24%.

14. The method according to claim 1, characterized in that the injected substrate and the enzyme through a vertical or horizontal wellbore in the reservoir or in certain intervals of the formation, which in the latter case are isolated from each other packer sections and/or inert buffer liquids.

15. The method according to claim 1 or 13, characterized in that the layer of pre-fetch composition, blocking high permeability intervals, as such, use of oil-water emulsion.

16. The method according to claim 1 or 14, characterized in that the hole previously injected inert buffer liquid with a density greater or lesser density uglevodorodyonogo substrate.

17. The method according to claim 1, characterized in that the bore is closed for 2-24 h under pressure to respond in accordance with the rate of formation of organic acids and scope of the impact along the strike of the bottomhole zone of the formation.

18. The method according to claim 1, wherein the well is completed directly after processing without intermediate damping to change the layout and make it a given technology is practical mode, creating optimal conditions for removal from the reservoir or displacement into the formation plugging of the processed substrate and the enzyme zone.

19. The method according to claim 1, characterized in that during the development choose the bottomhole pressure and rate of its change, recording the dynamics of the buffer and annulus pressure and the change in dynamic level and physical-chemical properties of produced fluids, gradually or sharply reducing the bottomhole pressure for the most complete removal products clogging of the bottom zone, after which establish and maintain the technological regime of the well at the level of warning induced decrease the permeability zone and/or maximizing hydrocarbon production for a specified period of time.

20. The method according to claim 1, characterized in that the set a given technological regime well, record the dynamics of the parameters of the technological regime and physico-chemical properties of produced fluids and rejecting their values beyond the established boundaries of the re-make treatment of bottom-hole zone and/or modify the operation of the wells in such a way as to ensure maximum production of hydrocarbons.

21. The method according to claim 1, characterized in that the set a given mode of injection water injection wells, register dynamics parameters the ditch technological modes of injection and rejecting their values beyond the established boundaries of the re-make treatment of bottom-hole zone and/or modify the operation of the wells thus, to provide the specified pressure, and/or a predetermined acceleration and/or maximum coverage of the formation water.

22. The method according to claim 1, characterized in that the injection of substrate and enzyme continued and/or repeated to ensure the required capacity of the zone of influence of the substrate and the enzyme and/or oil under specified temperature and pressure conditions.

23. The method according to claim 1, characterized in that at the moment of injection of substrate and enzyme in the bottomhole zone of low permeability interval of the reservoir effect on other intervals of this well, and/or reduce the maximum bottom-hole pressure in the associated production wells, and/or stop the processing time of the injection of water into injection wells.

24. The method according to claim 1, wherein during and/or after the injection of substrate and enzyme in the formation he is under the influence of heat and/or depressions and/or repression, and/or acoustic and/or electromagnetic and/or vibro-seismic vibrations.

25. The method according to claim 1, characterized in that define the geologic characteristics of each interval of the bottomhole zone based on the results of photocamera and/or thermometry.



 

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The invention relates to the oil industry, specifically to methods for processing bottom-hole zone of irrigated hydrophobic layer of powdery materials

The invention relates to the field of gas and gas condensate, namely the removal vodokanalstroi mixture from the well

The invention relates to the field of gas and gas condensate, namely the removal vodokanalstroi mixture from the wells containing produced water and gas condensate, especially from wells with abnormally low formation pressure

The invention relates to the oil industry

The invention relates to reagents having the ability to remove hydrogen sulfide and mercaptans from gases, oil, oil, produced water, drilling fluids, and can be used on objects of oil production, refining, petrochemicals for their neutralization by neutralizing biogenic sulfur compounds

FIELD: oil and gas production.

SUBSTANCE: invention provides a method of developing oil pool allowing production of oil from water-rich oil reservoir under difficult geological-tectonic conditions in the last development stage. In the method, neutral salt of carbonic acid and acid solution are forced into formation through injecting well with water generated in gas-liquid fringe created in formation. After pumping of neutral salt of carbonic acid, acid solution is pumped by portions alternating with water pumping. Before pumping of acid solution portions beginning by at least second portion, selective insulation of high-permeable formation intervals is performed. Aforesaid neutral salt of carbonic acid utilized is sodium carbonate aqueous solution or aqueous suspension of calcium carbonate and aforesaid acid solution is aqueous hydrochloric acid solution. Selective insulation of high-permeable formation intervals involves use of freshly prepared controllable viscoelastic composition containing water-soluble acrylic polymer, cross-linking agent, thermal stabilizer, surfactant, and water. Summary concentration of acid solution is determined from concentration of neutral salt of carbonic acid on the base of stoichiometric proportions.

EFFECT: increased efficiency of maintaining formation pressure and thereby oil recovery of formation due to leveled displacement front and reduced probability of the rupture of formation rock backbone, and simplified control of phase state of gas-liquid fringe by changing pressure of pumped acid solution portions.

8 cl

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