The method of treatment of an oil reservoir with heterogeneous reservoirs

 

The invention relates to the oil industry, in particular to methods for increasing oil recovery from oil fields with heterogeneous reservoirs. In the method of treatment of an oil reservoir with heterogeneous reservoirs hold alternating the injection of alkaline rims clay suspension and dispersion of the polymer in alkaline rims impose additional surfactants and they are pre-foaming, alkaline dispersion of another polymer is added reagent "Comet-R and filter the oil through the production well. The volumetric ratio of the fringes, the total volume injected rims and the number of cycles is chosen based on the specific geological situation at the well and the desired radius of processing. For the preparation of alkaline solutions using sodium hydroxide or potassium hydroxide, soda ash, or food, or a mixture thereof. The technical result is to limit the pickup of high-permeability layers, involvement in the development of less permeable layers, as well as increasing the pace of development and reservoir recovery. table 1.

The invention relates to the oil industry, in particular to methods oveloading collectors by alternating injection into an injection well of alkaline rims solution of polyacrylamide (PAA) and clay suspension and selection of oil through the production well /1/.

The disadvantage of this method is the low rate of deposits due to the low volume of plugging precipitate and low strength properties.

Closest to the invention to the technical essence is a way of influencing the accumulation of heterogeneous reservoirs, including the selection of oil through the production well and alternating the injection of alkaline fringes of the variance of the derivative of cellulose and clay suspension /2/.

The known method allows you to align the profile of injection wells to enhance the recovery of oil deposits. However, the effectiveness of the application of the method is low due to the small volume of incoming sediment plugging. This leads to premature water breakthrough at the production well at a more high-permeability of the formation and reduction of the current oil recovery.

The invention solves the problem of increasing the volume of cementing sediment with increasing its mechanical properties for enhanced oil recovery reservoir.

The task is solved in that in the method of treatment of an oil reservoir with heterogeneous reservoirs, including the selection of oil through the production well and alternating the injection of alkaline rims clay suspension and dista surfactants and their pre-foamed, in alkaline dispersion of polymer impose additional reagent "Comet-R".

The essential features of the invention are: 1) selection of oil through the production well; 2) alternating injection of alkaline rims polymer dispersion and clay suspension; 3) in alkaline fringe is added surfactant; 4) alkaline rims pre-foaming; (5) alkali-polymer dispersion is added reagent "Comet-R".

Signs 1-2 are common with the prototype, signs 3-5 are the salient features of the invention.

Summary of the invention In the development of oil deposits with heterogeneous reservoirs by waterflooding and premature breakthrough of injected water in the high-permeability layers in oil wells. This leads to a decrease in the efficiency of oil displacement by water, and lower oil recovery. To prevent and combat water breakthrough in the high-permeability layers are working on the alignment profile injectivity of injection wells. However, the effectiveness of such facilities from low due to the small volume of incoming sediment plugging, resulting in lower current recovery p is icene oil recovery by increasing the volume of cementing sediment with increase of its strength properties.

The problem is solved by the following set of operations.

On deposits of conduct alternating the injection of alkaline rims clay suspension and dispersion of the polymer in alkaline fringe is added surfactants and they are pre-foaming, and alkaline-polymer dispersion further introduces the reagent "Comet-R". Through the production well are a selection of oil.

Sequential injection of alkaline rims clay suspensions and dispersions of polymer exercise alternating cycles with the aim of increasing the number of zones of mixing and, consequently, the volume of cementing mass, resulting from the interaction between polymer and clay in an alkaline environment.

The volumetric ratio of the fringes, the total volume injected rims and the number of cycles is chosen based on the specific geological situation at the well and the desired radius of processing.

For the preparation of alkaline solutions using sodium hydroxide or potassium hydroxide, soda ash, or food, or a mixture thereof.

As polymers can be used various brands of Kamala (water-soluble polymer fine granular or powder from white to cream color, available OTA 1020, RD-1004, CS-6, ACCOTROL and others).

Reagent "Comet-R (TU 2458-019-25690359-99) is a copolymer of methacrylic acid and sodium salt of methacrylic acid obtained by the method of solution copolymerization.

As surfactants can be used in a variety of anion active or nonionic surface-active foaming agents or their mixtures (sulfonic acid, OP-10, neonol, neprinol and others).

An alkaline environment promotes polymerization of the polymer and increases its resistance to degradation in situ. While clay particles are maximally swell, increasing their flexibility and mobility, moreover, increases the adsorption of the polymer on the bentonite, which contributes to the occurrence of hydrogen bonds on the surface of particles and hardening of the composition in the reservoir. The table shows the results of laboratory studies to determine the volume of sediment and static shear stress (SNA), which characterizes the strength properties of the system.

As can be seen from the table, the proposed system compared to the prototype are characterized by large amounts of sediment and large value of the SNA. Improved strength characteristics of the resulting systems allow for the effects on the reservoir d of oil through the production well. Examples of specific performance.

Example 1. By flooding develop an oil field with the following characteristics: effective thickness of the reservoir is 10 m, the porosity - 0.18, absolute permeability - 0,150 mm, the temperature of the reservoir - 85oWith the initial reservoir pressure - 26,0 MPa, the viscosity and density of oil in the reservoir, respectively - 0.8 MPa-s and 0,765 g/cm, viscosity of water - 0.35 MPa, initial oil and water saturation, respectively, of 0.6 and 0.4, the pressure of saturation of 76.5 MPa, the gas factor is 75 nm3/m3, the ratio of the permeability of high-permeability and low-permeability layers is equal to 2.8. In high-permeability of the formation has been a breakthrough of injected water in the production well, water cut reached 95%.

On the site of the Deposit hold alternate injection via the injection well an alkaline rims clay suspension and dispersion of Kamala, which was previously introduced surfactants (sulfonic acid) and which were pre-foamed. And in the variance of Kamala before foaming was introduced reagent "Comet-R". Through the production well are a selection of oil.

Example 2. Developing a petroleum reservoir as in example 1. On the site of the Deposit hold alternating injection after having extracted the den surfactant (OP-10) and which were pre-foamed. And in the variance of the PAA before foaming was introduced reagent "Comet-R". Then, through the production well are a selection of oil.

Example 3. Developing a petroleum reservoir as in example 1. On the site of the Deposit hold alternating the injection of alkaline rims clay suspension and dispersion PAA (DKS-ORP-F-40NT), which was previously entered mixture of surfactants (OP-10 and sulfonic acid) and which were pre-foamed. And in the variance of the PAA before foaming was introduced reagent "Comet-R". Then, through the production well are a selection of oil.

The application of the proposed method the impact on the accumulation of heterogeneous reservoirs allows for the amplification of plugging properties of the composition include the development of low-permeability layers to increase the pace of development and the recovery of oil deposits.

Sources of information 1. Patent of the Russian Federation 2044872, E 21 In 43/22, 1995

2. Patent of the Russian Federation 2184218, E 21 In 43/22, 2001

Claims

The method of treatment of an oil reservoir with heterogeneous reservoirs, including the selection of oil through the production well and alternating the injection of alkaline rims clay suspension and the polymer dispersion that is different is anywayt, in alkaline dispersion of polymer impose additional reagent "Comet-R".

 

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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

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

FIELD: oil and gas production.

SUBSTANCE: invention is intended for use during development of oil pools at different waterflooding phase for intensifying functioning of producing wells and increasing current oil recovery of formation. Composition contains, wt %: liquid hydrocarbon 10.0-20.0, oil-soluble surfactant 0.3-5.0, water-soluble or water-oil-soluble surfactant 0.1-1.0, superfine hydrophobic material 0.1-2.0, and water (the rest). Composition may further contain 0.3-5.0% calcium chloride. Oil recovery is increased owing to hydrophobization of formation structure, reduction of surface tension in water/rock/oil phase boundary, increase in detergent power of polluted surface, increase in composition viscosity, and increase of relative permeability of the formation for hydrocarbon phase as compared with water phase.

EFFECT: increased oil recovery.

2 cl, 2 tbl, 2 ex

FIELD: oil and gas production.

SUBSTANCE: composition contains 0.05-2.5% of hydrophobic power, 0.05-10% of ethylene/vinyl acetate copolymer, and organic solvent. Composition intensifies oil production owing to increased effective radius of formation bottom area treatment, prevention of moistening inversion effect upon fall of hydrophobic agent concentration, and, consequently, decreased volume of simultaneously produced water.

EFFECT: increased oil production, prolonged overhaul period, improved environmental safety, and lowered production expenses.

2 tbl, 3 ex

FIELD: oil and gas extractive industry.

SUBSTANCE: method includes drilling product and force wells, forcing gas and water through force wells into separate zones of productive bed and extraction of hydrocarbons from product wells, forming separate gas, water and hydrocarbon saturated areas with major contents of respectively gas, collected therein for later use, water and hydrocarbons, periodical pumping of collected gas from formed gas saturated zones to water saturated zones, periodical pumping of water to gas saturated zones is performed. It is possible to pump collected gas to water saturated zones in form of gas-water mixture. It is possible to pump in passing gas of current deposit. It is possible to pump hydrocarbon or non-hydrocarbon gas from other sources. It is possible to pump water with admixture of specifically selected chemical reagents or compositions thereof. When gas content in water saturated zones reaches from 0.1 to 28% from water content in water saturated zones it is reasonable to generate resilient waves with frequency within range from 0.0001 to 45 KHz and amplitude within range from 0.02 to 2.8 MPa. It is reasonable to pump gas and water to separate areas of productive bed with concurrent generation of resilient waves in there with frequency within range from 0.0001 to 45 KHz and amplitude within limits from 0.02 to 2.8 MPa.

EFFECT: higher efficiency.

7 cl, 5 dwg

FIELD: oil extractive industry.

SUBSTANCE: method includes pumping of Sulfacella water dispersion into bed through force well and extraction of oil through extracting well, said dispersion additionally containing non-ionogenic surfactant AF9-12 with following ratio of components, in percents of mass: Sulfacella 0.5-1, AF9-12 0.01-0.1, water- the rest, while, before pumping of said dispersion mineralized water is pumped with total mineralization until 290 g/l in amount of 10% from volume of said dispersion, when pumping said dispersion prepared in fresh water, drain water is previously pumped, and when pumping said dispersion made from drain or bed water, bed water is previously pumped. For preparation of said dispersion fresh, drain or bed water is used with mineralization till 290 g/l.

EFFECT: higher efficiency.

2 cl, 2 tbl

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 and gas extractive industry.

SUBSTANCE: method includes placing water solution of carnallite ore, either modified, concentrated, or mixtures thereof, said solution is used at maximal for well temperature conditions concentration and is pumped in amount, necessary and enough for forming a hydraulic column in well shaft above ceiling of productive bed and along remaining shaft height well is filled with water up to mouth. Carnallite ore used has composition, in percents of mass: potassium chloride 20.5-21.5; sodium chloride 19.5-22.5; magnesium chloride 24.0-27.0; crystallization water 29.5-30.5. Modified ore has composition, in percents of mass: potassium chloride 23.0-29.5; magnesium chloride 31.8-46.0; crystallization water - the rest. Said water solution is prepared by dissolving ore in fresh technical water, drained from oil preparation plants, or in bed water. In case of dissolving in bed water, the latter is pumped from well at temperature 60-90C. During perforation of well, value of technological liquid hydraulic column above productive bed ceiling is taken equal to (1.03-1.07)-(1.05-1.1)Pb, where Pb - productive bed pressure. Water solution of carnallite ore is used at density 1.23-1.37 t/m3. During use of said solution as working body of force wells it is used at density 1.05-1.20 t/m3, and solution also contains swelling inhibitor for argillaceous component of oil and gas bearing bed, like oxyethylenedendiphosphone acid, in amount 0.05-0.15% of used dissolved ore mass.

EFFECT: higher efficiency.

1 cl, 4 ex

FIELD: oil industry.

SUBSTANCE: method includes treatment of face area of oil bed by hydrophobic agent in organic solvent and pressing oil from collector with following delivery of oil from face area of product well for treatment of oil terrigenic bed, in form of hydrophobic agent solution of ethylene copolymer with vinylacetate in ethylbenzol or fraction thereof is used in relation 1:1 - 10, treatment of face area is performed with following ratio of components, in percents of mass: ethylene copolymer with vinylacetate 0.05-2.0, ethylbenzol or fraction 0.05-20.0, organic solvent - the rest.

EFFECT: higher efficiency.

2 tbl, 2 ex

FIELD: mining industry and alternative fuels.

SUBSTANCE: coal is affected by methanogenic consortium of microorganisms with culture medium utilizing continuous pumping of culture medium through wells and tank wherein methanogenic consortium of microorganisms with culture medium is placed. Tank is installed on the surface above wells and pumping of culture medium from the bottom of tank through methanogenic consortium of microorganisms. Process produces biogas and coal-water fuel.

EFFECT: increased yield of biogas to continuously effecting culturing of microorganisms.

1 dwg, 2 tbl

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