The method of regulating the permeability of a heterogeneous oil reservoir

 

The invention relates to the oil and gas industry, in particular to methods of displacement of residual oil, reducing the permeability of watered formations involving in the development of low-permeability oil-bearing areas and increase oil recovery. The technical result is the creation of an efficient method of regulating the permeability of a heterogeneous oil reservoir by reducing the permeability of high-permeability zones water-saturated reservoir. In the method of regulating the permeability of a heterogeneous oil reservoir, including injection into the reservoir through injection wells water suspension of chalk with subsequent injection of an aqueous solution of metal salts and oil production through production wells, as specified suspension of chalk pumped aqueous suspension of sludge from the clarifiers John WSSD - waste production of soda separation between fringes of fresh water, and as the aqueous solution of metal salts - mineralized waste water. table 2.

The invention relates to the oil and gas industry, in particular to methods of displacement of residual oil, reducing the permeability of watered formations involving in which abode oil deposits, including the injection into the formation via the injection well an aqueous solution of salts of polyvalent metal, an aqueous solution of alkali, followed by injection of the displacing agent (patent RF 2117143, IPC E 21 In 43/22, 33/138, 1996).

The disadvantage of this method is low efficiency insulation washed high flow channels of the formation, the high cost of reagents.

The closest way to the same destination to the claimed invention, the set of essential characteristics is the way to develop flooded oil fields, heterogeneous geological structure, including injection into the formation via the injection well an aqueous solution of ammonium chloride and extraction through production wells (RF patent 2115801, IPC6E 21 IN 43/22, 1997).

The disadvantage of this method is the lack of reduction of the permeability of a heterogeneous oil reservoir, as well as the preparation of water solutions of salts, as well as the high cost of the reagents.

Object of the present invention is to provide an effective method of regulating the permeability of a heterogeneous oil reservoir by reducing the permeability of high-permeability zones water-saturated reservoir.Lasta, including the injection into the reservoir through injection wells water suspension of chalk with subsequent injection of an aqueous solution of metal salts and oil production through production wells, according to the invention as specified suspension of chalk pumped aqueous suspension of sludge from the clarifiers John WSSD-waste production of soda separation between fringes of fresh water, and as the aqueous solution of metal salts - mineralized waste water.

The essence of the proposed method is consistent uploads in flooded oil reservoir via the injection well water suspension of the sludge from the clarifiers John WSSD - waste production of soda separation between fringes of fresh water, with subsequent zakachivanie mineralized waste water.

Water suspension of the sludge from the clarifiers John WSSD - waste production of soda is formed in the process of preparing crude brine for electrolysis when receiving an electrolytic alkali chlorine and hydrogen. The separation of the sludge from the brine is in the pits John, where the mixture is fed into a Central distribution plate.

Water suspension of the sludge from the clarifiers John SSD is a water-var is the remaining water suspensie sludge from the clarifiers John, g/cm3: Sodium chloride - 0,20-0,30 Calcium carbonate - to 0.060-0,120 magnesium Hydroxide - 0,005-0,012 Caustic soda - 0,020-0,025 ammonium Chloride - 0.005 to 0.0001 sodium Sulfate - 0,030-0,040 Hydrolyzed polyacrylamide - 0,00001 Impurities and water - the Rest
The hazard class belongs to the 4th class. During transportation does not require additional security measures. Environmentally friendly.

The mechanism of action of the aqueous slurry of the sludge from the clarifiers John filtering the reservoir fluid is to reduce the flow of the displacing agent through highly permeable water reservoir, the flow direction in the less irrigated land and involvement in the development of non-flooded the interlayers. The decrease of the flow of the displacing agent through flooded collector is achieved by an increase of the solid fraction at the expense of the formed precipitate. The mixture of the aqueous slurry of the sludge from saline waste water is directly in flooded reservoir. In the interaction of caustic soda, sodium sulphate suspension in water with ions of calcium and magnesium mineralized waste water, a solid precipitate of calcium sulfate and magnesium hydroxide. Hydrolyzed polyacrylamide promotes flocculation, okropne the ka displacing agent contributes to the reduction of water production wells, the increase in oil output.

The effectiveness of the method was determined experimentally by following the described method.

Example 1 (the proposed method). To filter samples, each of which represents a cemented quartz sand with a diameter of 40 mm and a length of 60 mm, the Volume of the pore space is 15 cm3. The sample is placed in kindergaten and saturated with formation water density 1,107 g/cm3. Determine the initial permeability at constant differential pressure of 0.01 MPa, which is 3,66 μm2.Experiments are performed at a temperature of 20oWith constant infiltration rate of 0.5 m/day.

Then through the sample is filtered sequentially 12 ml WSSD separated by two freshwater rims 6 ml, then filtered 26 ml of saline waste water density 1107 g/cm3. Residual permeability is determined at filtering waste water in the forward and reverse direction. The final permeability is 0.42 μm2. The results of the experiments proposed and the known methods are shown in table 1. The effectiveness of the method characterizes the degree of reduction of the permeability of the sample. According to the table shows that the proposed method is p> Thus, the results of the experiments show that by reducing the permeability of a heterogeneous reservoir the proposed method outperforms known by 20.3%.

To assess the advantage of the proposed method over the known examples of the method in field conditions.

Example 2. Skilled plot presents one injection and 5 producing wells. Operated object - terrigenous Devonian (layer D1). Reservoir properties of the formation are the following: the effective thickness of the reservoir - 7.5 m; porosity reservoir - 0,22, the injection capacity of the well is 550 m3/day. The flow rates of producing wells - 1.0 to 3.3 g/day. Production watercut - 84,3-98% (see tab. 2).

The proposed method is carried out in the following order. Well stop. After thorough mixing in the pump cementing unit to the injection well pump 8 m3WSSD separated by two freshwater rims 2 m3, push into the reservoir 24 m3mineralized waste water density 1107 kg/m3. Well stop for 72 h and put in the work. After exposure to the flow rate of oil wells increased to 1.6-4.0 tonnes/day, i.e. by 30.2%. The watercut sopostavitelnaya analysis of geologic settings shows the degree of decrease in the water content by the claimed method above 1.7 times, and the degree of growth of oil output more than in 2 times in comparison with the known method.

Thus, the results of the analysis of the operating parameters of production and injection wells show that the proposed method is better known as water capacity, and increasing oil production.

Conclusions: the technical-economic advantages of the proposed method:
- high efficiency insulation washed with saturated zones of the collector due to the greater degree of reduction of the permeability of a heterogeneous oil reservoir;
- low cost, cost-effectiveness and ease of implementation of the method;
- higher degree of growth of the well flow rate and reduce the water content in comparison with the known method;
- allows the use of waste chemical production and thereby contribute to environmental protection.


Claims

The method of regulating the permeability of a heterogeneous oil reservoir, including injection into the reservoir through injection wells water suspension of chalk with subsequent injection of an aqueous solution of metal salts and oil production through to the mA clarifiers John WSSD - waste production soda separation between fringes of fresh water, and as the aqueous solution of metal salts - mineralized waste water.

 

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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 60-90°C. 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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