RU2105142C1 - Method of increasing oil recovery from beds - Google Patents

Abstract

FIELD: oil production industry. SUBSTANCE: according to method, down-hole zones of injection and producing wells are subjected to treatment by suspension of highly dispersing hydrophobic silicone dioxide in organic solvent. Then water is injected into injection well. Oil is displaced from reservoir by hydrodynamic pressure of water from down-hole zone of producing well. EFFECT: higher efficiency. 4 cl, 1 tbl

Description

 The invention relates to the oil and gas industry, in particular to methods for increasing oil recovery of oil wells through the use of physico-chemical methods of stimulation. The invention can also be used to increase the life cycle of elements of oil and gas complexes (wells, drilling, oil pipelines, oil storages, terminals, etc.) by imparting complex protective properties to them: hydrophobic, acid repellent, anticorrosive, antifouling.

 The main method for extracting oil from formations is to force it to be displaced from the producing well by water pumped into the formation through an injection well under pressure and transporting oil to the earth's surface by a pump.

 In the process of extracting oil from the reservoirs, their filtration parameters change, which affect the productivity of the wells. In order to restore and increase production productivity and injectivity of injection wells, there are a large number of different methods of stimulating the formation: thermal, gas, hydrodynamic, microbiological, physico-chemical and vibroseismic methods of interphase catalysis and in-situ combustion, as well as their various combinations [1]. However, most of them do not have a sufficiently high efficiency in oil recovery and require large expenditures of energy and the use of expensive materials.

 Closest to the proposed one is a method of increasing oil recovery, including processing the bottom-hole zone of the injection well, pumping water into the injection well, displacing oil from the reservoir with hydrodynamic pressure of water, and delivering oil from the bottom-hole zone of the producing well to its mouth by a pump [2].

 The essence of the method lies in the fact that the oil is displaced from the reservoir by the hydrodynamic pressure of water through an injection well, the bottom-hole zone of which is pre-treated with Wacrer Chemie Extract-700 silicone emulsion, and the oil entering the bottom-hole zone is delivered to the mouth of the producing well by a pump.

 As a result of the application of this method, the injectivity of the injection well increases by 20-30%, and the production rate of production wells increases by an average of 5-8%, together with the cessation of water cut growth.

 The disadvantage of this method is a slight increase in injectivity of injection and production wells, the use of expensive chemical compounds in large quantities.

 The technical result achieved in the invention is to increase the injectivity of injection wells by 200-300% and increase the production rate of production wells by 3-4 times.

 The required technical result is achieved by the fact that in the method of increasing oil recovery, including processing the bottom-hole zone of the injection well, pumping water into the injection well, displacing oil from the reservoir by hydrodynamic pressure of water, and delivering oil from the bottom-hole zone of the producing well to its mouth with a pump, the bottom-hole zone is additionally treated production wells, while the bottom-hole zones of the injection and production wells are treated with a suspension of highly dispersed hydrophobic dioxide silicon in an organic solvent.

 The technical result is achieved to the greatest extent by the fact that the bottom-hole zones of the injection and production wells are treated with a suspension of highly dispersed hydrophobic silicon dioxide in an organic solvent with a concentration of 0.05-0.5 wt.% And 0.5-1.0 wt.%, Respectively. White carbon black, or aerosil, or talc, or perlite is used as highly dispersed hydrophobic silicon dioxide, and as an organic solvent, distillate or white spirit, or acetone, or gasoline, or kerosene, or petroleum ether, or hexane, or other organic solvents. Hydrophobic silica powders are inert materials with an average particle size of 5-50 microns and do not have a harmful effect on humans and the environment. A suspension is prepared by mechanical stirring of the calculated amount of hydrophobic silicon dioxide in an organic solvent for several minutes immediately before injection into the well.

Example. Work is underway to reduce injection pressure and increase the injectivity of an injection well with a sealed reservoir and low permeability and increase the production rate of the producing well. Before using hydrophobic silicon dioxide, the injection well has an injectivity of 5 m / day, at a wellhead pressure of 220 kg / cm ² . The production well’s production rate is: for liquid 3 m ³ / day, for oil 0.9 tons / day. 5 m ^{3 of} distillate containing 5 kg of finely divided silica are pumped into the injection well. Additionally, the bottom-hole zone of the producing well is treated by pumping a suspension of 6 m ^{3 into it} with a concentration of finely divided silica in the distillate of 0.3 wt.%. Then go to the injection of water through the injection well. After 2 hours of pump operation, the pressure at the wellhead decreased from 220 to 135 kg / cm ² . Thus, it was found that the use of a hydrophobic material with a concentration of 0.1-0.05 wt.% In an organic solvent leads to a 60% decrease in the injection pressure of an injection well with low reservoir permeability. The well treated with a suspension of hydrophobic silicon dioxide began to receive water with an injection rate of 120 m ³ / day, was pumped from a cluster pumping station and entered a stable mode of water intake, which lasts for more than a year. At the same time, the production rate of the producing well was: for the liquid 12.2 m ³ / day, and for oil - 3.17 t / day.

 The results of the remaining experiments are shown in the table.

 As follows from the table, the use of a suspension of highly dispersed hydrophobic silicon dioxide in an organic solvent with a content of 0.05-0.5 wt. % in injection wells leads to a decrease in injection pressure by 1.4-2.0 times and an increase in injectivity of the formation by 1.5-150 times, and treatment of the bottom-hole zone of production wells with a suspension containing 0.5-1.0 wt.% increases oil flow 3-7 times.

Claims (5)

 1. A method of increasing oil recovery, including processing the bottom-hole zone of the injection well, injecting water into the injection well, pumping the oil out of the reservoir with hydrodynamic pressure to deliver oil from the bottom-hole zone of the producing well to its mouth with a pump, characterized in that the bottom-hole zone of the producing well is further processed while the bottom zones of the injection and producing wells are treated with a suspension of highly dispersed hydrophobic silicon dioxide in an organic solvent e.  2. The method according to claim 1, characterized in that the bottom-hole zone of the injection well is treated with a suspension of highly dispersed hydrophobic silicon dioxide with a content of 0.05 to 0.5 wt. in an organic solvent.  3. The method according to p. 1, characterized in that the bottom-hole zone of the producing well is treated with a suspension of highly dispersed hydrophobic silicon dioxide with a content of 0.5 to 1.0 wt. in an organic solvent.  4. The method according to claim 1, characterized in that as a highly dispersed hydrophobic silicon dioxide, white carbon black, or talc, or aerosil, or perlite is used.  5. The method according to claim 1, characterized in that the distillate, or white spirit, or acetone, or gasoline, or kerosene, or petroleum ether, or hexane is used as an organic solvent.

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