RU2334079C1 - Well pump facility for oil production and water injection to stratum - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: production facility includes plunger pumps that can be positioned in a well in sequence. Well head pump drive is capable of reciprocating. Each of the plunger pumps has inlet and outlet devices with coupling rods. The facility also includes packer that can be positioned between strata, the upper stratum being a water-encroached productive formation for water, oil and gas mix production, and the lower one serving for water intake. Inlet hole is placed below the upper pump and made in the form of cylindrical vessel with water-repellent coating inside, upper side orifice and upper pump inlet jet inserted inside hermetically from above. The lower pump represents a cylinder inserted hermetically to channel of the packer with hollow plunger, the coupling rod of which is hollow and is rigidly connected to the cylindrical vessel. Inlet orifice of the lower pump includes two devices, the first being a channel connecting hollow coupling rod to the vessel, and the second a jet stopped from above with a side channel in the upper part to connect the hollow coupling rod to the inlet jet of the upper pump above the vessel. Ring section area between the inlet jet and the vessel is selected in such a manner that maximum speed of water oil mix flowing down at this section exceeds oil floating speed not more than by the factor of two, and minimal inlet jet volume between the side channel of stopped jet and the upper pump comprises at least half a volume of fluid supplied to the upper pump by suction.

EFFECT: improved quality of well separation of water, oil and gas mix into liquid phases and reduced cost of power with possibility of adjustable oil withdrawal from well.

1 dwg

Description

The invention relates to the oil and gas industry and can be used for oil production and disposal of produced water.

A device for producing oil from an irrigated reservoir is known (patent RU No. 2190094, IPC 7 ЕВВ 43/38, С02F 1/48, published in Bulletin No. 27 of 09/27/2002), containing two tubing strings screw pumps with a common shaft, a receiving chamber located opposite the production interval, a packer isolating the reservoir, the device is equipped with magnetizers installed in the receiving chamber, where the gas-oil mixture from the reservoir is supplied, while the common shaft of the screw pumps is made magnetic, while omagni Ateliers of screw pumps have different magnetic properties, for which they are made with a stepped inner surface and are installed on the upper pump with the extended part up, and on the lower pump with the expanded part down, with each magnetizer installed with the possibility of limited axial movement and fixing relative to the pump intake, moreover, the length of the input magnetizer selected at least the length of the perforated part of the casing.

The closest in technical essence is a downhole pumping unit for oil production and water injection into the reservoir (patent RU No. 2284410, IPC 7 ЕВВ 43/40, 43/14, published in bulletin No. 27 dated 09/27/2006), containing pumps with the possibility of their sequential location in the well and having input and output devices, a pump drive and a packer having the ability to be located between the layers in the well, one of which is with a water-oil mixture, and the other, the lower one, is for receiving water, while the downhole pumping unit contains screw pumps with their drive on Surfaces and a polished rod with an oil seal connecting the worm shaft of the upper pump with the worm shaft of the lower pump, the input device of which has radial holes for the aqueous phase from the oil-water mixture, and grooves, while the lower pump has a casing forming a channel for pumping water into the lower layer through this channel, and the grooves of the input device of the lower pump with the same rotation of the worm shaft.

Both analog and prototype have, to one degree or another, common flaws:

firstly, it is necessary to pre-select the ratio of the flow of screw pumps, which are not regulated during operation, depending on the ratio of the shares of oil and water in the reservoir fluid, which change during operation, and this does not allow efficient selection of products, i.e., in produced oil there may be water and, conversely, in the water that is pumped into the reservoir, there may be oil;

secondly, the low degree of borehole separation of the gas-oil mixture, which occurs only in the annulus of the well at the pump intake, which does not allow a high-quality separation of the gas-oil mixture into light (oil) and heavy (water) liquid phases;

thirdly, high electricity consumption by screw pumps.

An object of the invention is to improve the quality of downhole separation of the gas-oil mixture into liquid phases, as well as reducing the cost of electricity consumed with the possibility of controlled selection of oil from the well.

The stated technical problem is solved by a borehole pumping unit for oil production and water injection into a formation containing pumps with the possibility of their sequential location in the well and having input and output devices, a wellhead pump drive connected by rods to them, and a packer having the ability to be located between the layers in well, one of which is with a water-oil mixture, and the other, the lower one, is for receiving water, while the input device is located below the upper pump, and the output device of the lower pump is made in de channel passing through the packer to inject water into the lower layer.

What is new is that the pumps are plunger-driven, the drive is capable of reciprocating movement, and the input device of the upper pump is made in the form of a cylindrical tank with a water-repellent coating from the inside, the upper side opening and the inlet pipe of the upper pump sealed inwardly from above, while the lower the pump is made in the form of a cylinder, hermetically inserted into the channel of the packer, with a hollow plunger, the hollow rod of which is rigidly connected to the tank, and the input device is lower about the pump is made of two devices, the first of which is made in the form of a channel communicating a hollow rod with a tank, and the second is in the form of a pipe muffled from above with a side channel at the top communicating a hollow rod with an inlet pipe of the upper pump above the tank, while the annular cross-sectional area between the inlet pipe and the tank is selected in such a way that the maximum flow rate of the oil-water mixture down in this section exceeds the rate of rise of oil in water by no more than two times, and the minimum volume of the inlet pipe between the sides m channel of the plugged pipe and the upper pump must be at least half the volume of fluid entering the pump during suction.

The drawing schematically shows the design of the proposed downhole pumping unit for oil production and water injection into the reservoir.

The downhole pumping unit for oil production and water injection into the formation contains pumps 1 and 2, made plunger with the possibility of their sequential location in the well 3, and wellhead drive (not shown) of pumps 1 and 2 is made with the possibility of reciprocating movement.

Each of the plunger pumps 1 and 2 has input 4 and 5, as well as output 6 and 7 devices, respectively, as well as rods 8 and 9, respectively. The installation also contains a packer 10, which can be positioned between formations 11 and 12, with the top 11 being a waterlogged producing formation, from which the gas-oil mixture is produced, and the bottom 12 is a formation for receiving water.

The inlet device 4 is located below the upper pump 1 and is made in the form of a cylindrical tank with a water-repellent coating 13 from the inside and the upper side hole 14 and the inlet pipe 15 of the upper pump 1 sealed inwardly from above, that is, the lower part of the inlet pipe is part of the cylinder tank 4 and is also covered outside with a water-repellent coating.

The internal water-repellent coating 13 of the cylindrical tank 4 accelerates the separation of the gas-oil mixture into fractions (gas, water, oil).

The lower pump 2 is made in the form of a cylinder 16, hermetically inserted into the channel 17 of the packer 10 with a hollow plunger 18, the rod 9 of which is hollow and rigidly connected to the cylindrical tank 4. The input device 5 of the lower pump 2 is made of two devices, the first of which is made in the form of a channel 19, communicating a hollow rod 9 with a cylindrical tank 4, and the second in the form of a pipe 20 blanked from above with a side channel 21 at the top, communicating a hollow rod 9 with an inlet pipe 14 of the upper pump 1 above the tank 4.

The device operates as follows.

First, a cylinder 16 of the lower pump 2 is lowered into the well 3, for example, on a tubing string (not shown), on the outer surface of which the packer 10 is hermetically and rigidly fixed, and it is installed between the reservoir 11 from which the water-cut product is pumped out ( water-gas mixture), and reservoir 12, which produce the injection of water (for example, absorbing). After that, the packer 10 is planted and packaged, after which the tubing casing is removed from the well 3.

Next, the remaining part of the device is lowered into the well 3 on the tubing string 22 until the hollow plunger 18 of the lower pump 2 seals tightly into the cylinder 15 of the lower pump 2 and abuts against its upper end 23 of the packer 10.

The device is put into operation, while conventional plunger deep-well pumps (SHG) of any known design are used as plunger pumps 1 and 2, and the plunger (not shown) of the upper pump 1, connected to the rod 8, undergoes an axial reciprocating movement .

The hollow plunger 17 of the lower pump 2 is rigidly connected to the tubing string 22 by means of the hollow rod 9, the reservoir 4 and the inlet pipe 14 with the upper pump housing 1 and performs axial reciprocating movement due to tension-compression of the tubing string 22, resulting from the operation of the device, while the cylinder 16 of the lower pump 2 remains stationary thanks to the packer 10, which is packaged in the well 3.

During the operation of the device, the gas-oil mixture from the flooded productive formation 11 enters the downhole space 24 of the well 3, where, under the influence of gravity, the gas-oil mixture is divided into liquid phases and gas. Gas in the downhole space 24 between the tubing string 22 and the well 3 rises to the surface.

The liquid phases are separated, with the heavier liquid phase (water) settling down, and the lighter (oil) rising up. Oil, together with the remaining water that is not separated from the oil, in the downhole space 24 through the upper side hole 14 enters the tank 4 and the annular cross section s between the outer wall of the tank 4, made with a water-repellent coating 13 from the inside, and the inlet pipe 15 of the upper pump 1 is lowered while water-repellent (hydrophobic) coating 13 repels water, which improves the process of separation of the gas-oil mixture. At the same time, part of the heavy fraction (water) separated from the gas-oil mixture in an annular section s between the outer wall of the tank 4, made with a water-repellent coating 13 from the inside, and the lower part of the inlet pipe 15, the outer part of which is also covered with a water-repellent coating 13, goes down and through channel 19 enters the input device 5 of the lower pump 2.

At a certain moment, the main flow of the oil-gas mixture separated in the cylindrical container 4 changes the direction of movement by 360 ° and enters the annular space between the lower part of the inlet pipe 15 and the pipe 20 which is muffled from above, which rises up until it leaves the tank 4 and will not get inside the inlet pipe 15 of the upper pump 1, while oil, as a lighter fraction, floats up and enters the intake of the upper pump 1, and water, as a heavier fraction, settles down and through the side channel 21, to which comes only from above, enters the pipe 20, which is muffled from above, through which it goes down and enters the input device 5 into the hollow rod 9 of the lower pump 2. From the hollow rod 9, the water goes down, fills the hollow plunger 18 and is received by the lower pump 2 The operation of the device continues, with the upper pump 1 pumping oil from the inlet pipe 15, which rises up the tubing string 22 to the surface, and the lower pump 2 pumping water from the hollow rod 9 into the plaz t 12.

During the stroke of the hollow plunger 18 upward relative to the cylinder 16 of the lower pump 2, its suction valve 25 is open, and the discharge valve 26 is closed. As a result, water from the hollow plunger 18 enters the cylinder 16 under the suction valve 25, that is, a cycle of "suction". When the hollow plunger 18 moves downward relative to the cylinder 16 of the lower pump 2, the suction valve 25 is closed and the discharge valve 26 is open. As a result, water from the cylinder 16 of the lower pump 2 through the discharge valve 26 enters the reservoir 12, which absorbs the pumped water. In the future, the cycle of the device is repeated.

Missing oil, as a lighter fraction, in channel 19 can be solved by installing at the inlet of the input device 5 a lower pump 2 of a check valve (not shown), the density of which is lower than the density of water, but higher than the density of oil, then when the water level drops to channel 19, the latter will be blocked.

Oil non-penetration into the side channel 21 of the plugged pipe 20 during the operation of the installation is ensured by the design dimensions of the installation, namely, the annular cross-sectional area s between the inlet pipe 15 and the capacity 4 is selected so that the maximum flow rate of the oil-water mixture downward in this section exceeds the oil ascent rate in water no more than twice, and the minimum volume of the inlet pipe 15 between the side channel 21 of the pipe 20 plugged at the top and the upper pump 1 should be at least half the volume of liquid V, p flowing into the upper pump 1 during suction.

In order to reduce the negative impact of water on the flooded reservoir 11, the cylindrical tank 4 should be below the flooded reservoir 11, from which the gas-oil mixture is produced.

Depending on the proportion of oil supplied to the intake of the upper pump 1, the stroke length of the upper pump 1 is controlled by a drive (for example, a rocking machine) installed at the wellhead, i.e., with an increase in the water content of the gas-oil mixture entering the downhole space 24, the length is reduced stroke of the rod 8 and, accordingly, the stroke of the plunger (not shown) of the upper pump 1 and vice versa.

The proposed device allows to increase the efficiency of downhole separation (separation) of the gas-oil mixture into liquid phases due to the possibility of separation in the input device of the upper pump, as well as reduce the cost of electricity consumed due to the use of plunger pumps. In addition, the installation allows you to adjust the selection of oil from the well by selecting the stroke length of the plunger of the upper pump at the wellhead depending on the proportion of oil in the reservoir fluid.

Claims (1)

A downhole pumping unit for oil production and water injection into a formation, comprising pumps with the possibility of their sequential location in the well and having input and output devices, a wellhead drive of the pumps connected by rods to them, and a packer having the ability to be located between the layers in the well, one of which with a water-oil mixture, and the other, lower one for receiving water, while the input device is located below the upper pump, and the output device of the lower pump is made in the form of a channel passing through the packer for heating melting water into the lower layer, characterized in that the pumps are plunger pumps, the drive is capable of reciprocating movement, the input device of the upper pump being made in the form of a cylindrical tank with a water-repellent coating from the inside, the upper side hole and the inlet pipe of the upper pump, while the lower pump is made in the form of a cylinder, hermetically inserted into the channel of the packer, with a hollow plunger, the hollow rod of which is rigidly connected to the tank, and the input device of the lower pump is made of two devices, the first of which is made in the form of a channel communicating a hollow rod with a tank, and the second is in the form of a pipe muffled from above with a side channel at the top communicating a hollow rod with an inlet pipe of the upper pump above the tank, and the area the annular section between the inlet pipe and the tank is selected so that the maximum flow rate of the oil-water mixture down in this section exceeds the rate of oil floating in the water by no more than two times, and the minimum volume of the inlet th nozzle side channel between the nozzle and the upper muffled pump must be at least half the volume of liquid entering the pump during suction.