RU2190757C1 - Process of extraction of oil - Google Patents

Abstract

FIELD: oil and gas production, production of oil without burning of associated gas in flares. SUBSTANCE: process includes preliminary drilling in oil field of at least two interacting wells and running of one well as producing well and of the other well as injection well. Separator to separate associated gas from oil extracted from pool is set on producing well. Piston pump with mixing unit of cavitation type is mounted on injection well. Conduit terminates at pump and gas line is installed from above-mentioned separator to mixing unit. While producing well operates all associated gas is transformed with the aid of piston pump and mixing unit to stable water and gas dispersion with bubble size from 1 to 10 μm with ratio of volumes of water and gas in bounds from 1:1 to 1:10 correspondingly and pressure between 100 and 300 atm. Produced water and gas mixture is fed into poll through injection well. EFFECT: total utilization of associated gas, enhanced degree of extraction of oil from pool and improved ecology. 1 cl, 1 dwg

Description

 The invention relates to the oil industry and can be used for oil production without burning associated gas in flares.

 A known method of oil production, including the breakdown of the reservoir into groups of interacting wells and the operation of each well in the group in periodic mode. The operation of each well in the group is carried out in a periodic three-stage mode, while at the first stage the produced fluid is pumped into the oil and gas gathering system, at the second stage - into other wells of the group, and at the third stage the well is stopped and fluid is pumped into it from other wells of the group (see Patent of the Russian Federation 2081302 C1, IPC 6 E 21 B 43/00, 10.06.1997).

 Re-injection into the reservoir of part of the produced formation water causes the effect of maintaining reservoir pressure and reduces the cost of transporting, preparing and disposing of this water at the treatment point, but at the same time, the gas coming along with the produced oil is sent to the collection reservoir and for various reasons cannot be It is useful in the place of extraction, and burned in torches.

 A known method of operating gas lift wells, including the production of a gas-liquid mixture from oil wells, separating the gas phase in the separator and its subsequent injection into gas lift wells. Pre-group highly debit oil wells with high gas content and gas lift with a mode of operation that provides the highest total oil withdrawal (see patent of the Russian Federation 2157449 C2, IPC 7 E 21 V 43/00, 10.10.2000).

 However, with this method of oil production, formation pressure is not maintained, and therefore, it is impossible to effectively use the capabilities of the oil reservoir.

 Also known is the closest in technical essence gas-lift operation of wells by injecting a gas-liquid mixture into the annular space of a well using a booster pump installation (see U.S. Patent 4,711,306, IPC 7 E 21 B 43/00, 08/12/1987).

 The gas-liquid mixture is pumped by the booster pump unit into the annular space of the well between the production string and the tubing string, and their cavity and annular space are disconnected by the packer, and their connection for the gas-liquid mixture flow is through an opening located in the immediate vicinity of the packer.

 However, this method does not have the ability to maintain a given bottomhole pressure during the operation of the well and the full use of its capabilities, while not all associated gas is used for injection, and therefore, there remains the problem of using the remaining part of the gas.

 The objective of the invention is the complete utilization of associated gas and increasing the degree of extraction of oil from the reservoir, as well as improving the environment by eliminating gas flaring.

 The specified technical result is achieved in that the method of oil production includes pre-drilling at least two interacting wells on an oil field and operating one as a producer and the other as an injection, while a separator is installed on the production well for separating associated gas from the oil extracted from the formation and a piston pump with a cavitation-type mixing device is mounted on the injection well, while a water conduit is brought to the pump, and a gas supply to the mixing device from the specified separator, and during production well operation, all associated gas is converted into a stable water-gas dispersion with a piston pump with a mixing device with a gas bubble size of 1 to 10 microns (microns) in the ratio of water and gas volumes ranging from 1: 1 to 1 : 10, respectively, and a pressure of from 100 to 300 atm (atmospheres), and the resulting water-gas dispersion is fed into the reservoir through the injection well. Several production wells can be located around one injection well, and the ratio of water and gas volumes can be adjusted by changing the water supply and / or the number of connected production wells.

 The drawing shows a group of interacting wells 1 and 2 drilled into an oil reservoir 3. Wells 1 and 2 are equipped with production cores 4 and 5 and tubing strings 6 and 7, respectively. Well 1 is intended to be operated as production, and well 2 is injection. Well 1 is provided with a line 8 for supplying produced oil to a separator 9 installed in well 1, from which a line 10 for supplying oil to a main pipeline (not shown) and a gas line 11 connected to a mixing device 12 of the piston pump 13 mounted on the well 2. the device 12 is made of cavitation type, a water line 14 for supplying water is connected to the pump 13. The mixing device 12 is connected by a water-gas dispersion supply line 15 to a column 7 of tubing of an injection well 2. All lines are equipped with adjustable valves.

 The production method is as follows.

 When you turn on the production well 1, the oil extracted from it is fed through the supply line 8 to the separator 9 to separate associated gas from the oil. Oil is supplied through line 10 to the main pipeline, and all associated gas obtained through gas line 11 is supplied to a cavitation mixing device 12 of a piston pump 13, to which water is supplied via a water conduit 14. In the mixing device 12, by means of cavitation, the associated gas and water are converted into a stable water-gas dispersion (mixture) with a gas bubble size of 1 to 10 μm, a ratio of water and gas volumes ranging from 1: 1 to 1: 10 and a pressure of 100 to 300 atm, which provide adjustment of the pump 13 and valves. These parameters of the water-gas dispersion ensure its stable state over a long period of time. The resulting water-gas dispersion is fed through line 15 to column 7 of the tubing of injection well 2, and then the water-gas dispersion enters the reservoir of oil reservoir 3. Around injection well 2 (there may be several of them in reservoir 3), several production wells 1 can be located, and adjusting the ratio of the volumes of water and gas can be additionally carried out by changing the number of connected producing wells 1. Part of the gas injected into reservoir 3 remains pinched in the pores of reservoir 3, and the other part is secondary recovered through a production well 1 together with a new portion of the gas returns to the reservoir 3 reservoir.

 Thus, the problem of utilization of associated gas at the field is solved and at the same time the problem of increasing the degree of oil recovery from the reservoir of oil reservoir 3 is solved, while gas flares that violate the environment are eliminated.

 This method, compared with the method of oil production by injecting water into the reservoir, allows you to additionally extract 10 ... 20% of the volume of reservoir oil.

Claims (2)

 1. A method of oil production, including preliminary drilling on an oil field of at least two interacting wells and operating one as a producer and the other as an injection, while a separator is installed on the production well for separating associated gas from the oil extracted from the formation, and on the injection a piston pump with a cavitation-type mixing device is mounted in the well, while a water conduit is brought to the pump, and a gas line from the specified separator to the mixing device, and during operation With the help of a piston pump with a mixing device, all associated gas is converted into a stable water-gas dispersion with a gas bubble size of 1 to 10 μm, a ratio of water and gas volumes ranging from 1: 1 to 1:10, respectively, and a pressure of 100 to 300 atm and the resulting water-gas dispersion is fed into the reservoir through the injection well.  2. The method according to p. 1, characterized in that several producing wells are located around one injection well, and the ratio of the volumes of water and gas is adjusted by changing the water supply and / or the number of connected producing wells.