RU2108449C1 - Method for development of oil deposit - Google Patents

Abstract

FIELD: oil production industry. SUBSTANCE: according to method, oil is recovered through producing wells. Working agent is injected through injection wells in cyclic mode. Inflow zone is subjected to seismic-acousting treatment. Undertaken in producing well located in zone of seismic-acoustic operation is forced recovery of liquids. Transfer to forced mode of operation is effected by step-by-step increase of well output. EFFECT: higher efficiency.

Description

 The invention relates to the oil industry and may find application in the development of an oil reservoir with a low permeability reservoir.

 A known method for the development of oil deposits, including the injection of a working agent through injection wells and the selection of oil through production wells [1].

 The known method does not allow to develop an oil reservoir with the achievement of high oil recovery.

 A known method of developing an oil reservoir, including the injection of a working agent through injection wells, oil extraction through production wells and forced selection of liquid on the part of production wells [2].

 The known method allows to increase oil production, however, a significant part of the oil reserves remains in the reservoir.

 Closest to the invention in technical essence is a method of developing an oil reservoir, which includes taking oil through production wells, pumping a working agent through injection wells in a cyclic mode, and conducting seismic and acoustic effects on the reservoir site [3].

 The known method allows you to limit the flow of water, increase the current oil production and the final oil recovery of the reservoir, however, some of the reserves remain in the reservoir, especially in reservoirs with low permeability reservoirs.

 The proposed invention solves the problem of increasing oil recovery deposits.

 The problem is solved in that in the method of developing an oil deposit, including oil extraction through production wells, pumping a working agent through injection wells in a cyclic mode and conducting seismic acoustic stimulation in the contraction zone, according to the invention, forced extraction is carried out in a production well located in the seismic acoustic impact zone liquids, while access to the forced mode is carried out by a stepwise increase in the flow rate of the well.

The essential features of the invention are:
1. The selection of oil through production wells;
2. Injection of a working agent through injection wells in a cyclic mode;
3. Conducting seismic-acoustic effects in the contraction zone;
4. Conducting forced selection of fluids in the producing well;
5. The location of the producing well - in the zone of seismic acoustic impact;
6. The implementation of access to the forced mode stepwise increase in the flow rate of the well.

 Signs 1-3 are common with the prototype, signs 4-6 are the salient features of the invention.

 Known methods for developing oil deposits make it possible to select the main oil reserves from the reservoir, however, some of the reserves remain in the reservoir, especially in reservoirs with low permeability reservoirs, which reduces the oil recovery of the reservoir. The proposed invention solves the problem of increasing oil recovery deposits. The problem is solved by the following set of operations.

 Wells are placed in the deposits according to the in-line development system and oil is extracted through production wells and the working agent is pumped through injection wells in a cyclic mode. At the same time, seismic-acoustic impact is carried out on the deposits in the contraction zone. As practice shows, seismic-acoustic impact through production wells has a range of about 2 km. In a production well located in the zone of seismic-acoustic impact and in the zone of contraction, forced selection of liquids is carried out. Around such a well there is a forced selection zone. Bringing the well to the forced fluid withdrawal mode is carried out by a stepwise increase in the well production rate each time by approximately 30% compared with the previous production rate until the bottomhole pressure is reached.

 With a decrease in bottomhole pressure, a proportional increase in the flow rate of the well occurs until the optimum bottomhole pressure is reached. After this, with a further decrease in bottomhole pressure, a sharp deceleration of the flow rate growth occurs, and then its decrease. This effect is explained by the beginning of the filtration of carbonated fluid and the closure of the pores of the formation in the bottomhole zone of the well. The step-by-step conclusion of the well to the forced selection mode allows the formation of forced fluid flows without sharp hydrodynamic loads on the formation, which helps to maintain the permeability of the formation and increase the flow rate of the wells.

 A special effect on the increase in oil production occurs when combining zones of seismic-acoustic effects, zones of contraction and zone of forced selection of liquids.

 The combined use of the above actions improves the oil recovery of the reservoir.

Example. An oil reservoir of the Romashkinskoye field is being developed with the following characteristics: porosity 11.9% permeability 0.029 μm ² , oil saturation 61.1%, absolute mark of water-oil contact 870 m, average oil saturated thickness 4 m, initial reservoir pressure 11 MPa, reservoir temperature 25 ^o С, reservoir oil parameters: density 930 kg / m ³ , viscosity 46 MPa • s, saturation pressure 1.8 MPa, gas content 15.2 m ³ / t, sulfur content 3.64%.

Wells are placed on the deposits in a row water flooding system with 2 rows of injection wells and 5 rows of production wells. The middle rows of producing wells form a contraction zone. Oil is taken through production wells and the working agent is injected through injection wells in a cyclic mode: through 1 row, the working agent is pumped - highly mineralized water from a lower horizon with a density of 1180-1200 kg / m ³ , for 15 days, 2 rows are stopped for 15 days, then in the next 15 days the functions of the series are changed to the opposite. At the same time, seismic-acoustic impact is carried out on the deposits in the contraction zone through the first production well located in the contraction zone. To create a seismic-acoustic impact, an electrohydrodynamic emitter with an energy of 1 kJ, a signal frequency of 200 to 3000 Hz, a signal send frequency of 1 in 10 s for 14 days is used. As practice shows, seismic-acoustic impact through production wells has a range of about 2 km. In the second production well, located at a distance of 500 m from the first, that is, in the zone of seismic-acoustic impact and in the zone of contraction, forced selection of liquids is carried out. Bringing a well to the forced fluid withdrawal mode is carried out by incrementally increasing the flow rate of the well each time by approximately 30% compared to the previous flow rate until the optimum bottomhole pressure is reached, i.e. from a flow rate of 20 m ³ / day at a bottomhole pressure of 13 MPa to a flow rate of 80 m ³ / day at bottomhole pressure of 8 MPa through an increase in flow rate to 26, 35, 46, 60, 80 m ³ / day.

 As a result of development, the oil recovery coefficient of the development area increased by 7% and amounted to 0.55%.

 The application of the proposed method will improve oil recovery of oil deposits with low permeability reservoirs.

Claims (1)

 A method of developing an oil reservoir, including oil extraction through production wells, pumping a working agent through injection wells in a cyclic mode, and conducting seismic and acoustic effects in the contraction zone, characterized in that forced extraction of liquids is carried out in the production well located in the seismic and acoustic zone, access to the forced mode is carried out by a stepwise increase in the flow rate of the well.