RU2405925C1 - Oil well pumping unit for simultaneous separate operation of two reservoirs - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: oil well pumping unit for simultaneous separate operation of two reservoirs comprises flow column, cable, packer installed between reservoirs, by-pass, upper jacket-enclosed pump - plunger one with stem, and lower pump communicated with below-packer space, electric submersible one, with electric motor, for pumping of products from appropriate reservoirs, unit of cable sealing. Discharge of electric submersible pump is communicated by nozzle to upper jacket, which is on top communicated to flow column and is equipped with side channel, communicating intake of upper pump to above-packer space. Nozzle communicating discharge of lower pump to flow column is equipped with additional check valve. Plunger pump is arranged as insert with the possibility of tight interaction with inner surface of process nozzle of upper jacket. Pressure of packer fit is less than the rated one for controlled valves of check valve.

EFFECT: feature of alternate pumps operation, possibility to use insert plunger pump, elimination of liquid leak in process of pumps lifting, possibility to pump reagents into lower reservoir and flushing of tube side below packer without withdrawal of plant from well.

2 dwg

Description

The proposal relates to the oil industry, in particular to downhole pumping units for the simultaneous separate operation of two reservoirs.

A well-known sucker rod pumping unit for the simultaneous operation of two layers in a well containing a column of elevator pipes, a column of rods, a packer, a liner and a differential pump. Moreover, the suction and discharge valves of the upper section of the pump are installed on the side of the cylinder, and a self-sealing packer is placed between them (Simultaneous separate operation of multilayer oil fields. / R.A. Maksutov, B.E.Dobroskok, Yu.V. Zaitsev. - M: Nedra , 1974. - Page 89, Fig. 54). This installation produces a separate rise in the production of formations: the bottom - along the string of elevator pipes, the top - along the production casing of the well.

The disadvantages of the installation are the complex design, the inability to study the reservoirs during operation (determination of bottomhole and reservoir pressures), if it is necessary to remove the pump, it rises together with the upper packer, which contributes to its wear and decrease the reliability of the installation, in addition, as a result of the “piston” effect created by the packer during the rise, the product spills from the production casing of the well. The location of the suction valve of the upper section of the pump under the packer, and the discharge valve above the packer increases the harmful space of the pump, which reduces its performance. In addition, the installation has low productivity for pumping out the products of the lower layer due to limitations in the diameter of the plunger of the lower section, which, based on the principle of the differential pump, must have a diameter smaller than the diameter of the plunger of the upper section. Another disadvantage of the installation is that the differential pump is driven by one column of rods and there is no possibility of separate regulation of the performance of the lower and upper sections of the pump.

Also known is a downhole pumping unit for the simultaneous operation of two layers in a well, comprising a column of elevator pipes, a packer, a liner and two separate electric centrifugal pumps with separate cables supplying the products of the upper and lower layers to one column of elevator pipes, through which it is supplied to the surface, production of the lower reservoir is fed by the lower pump to the column of elevator pipes along the circumferential casing, in which a channel is made for communicating the reception of the upper pump with the over-pack space of the well (One Modern separate exploitation of multilayer oil fields. / R.A. Maksutov, B.E. Dobroskok, Yu.V. Zaitsev. - M .: Nedra, 1974. - Pages 106-107, Fig. 63a).

The disadvantage of the installation is that it does not allow a separate rise and measurement of the production rate of each of the layers. Other disadvantages of the installation are the complexity of installation at the well, the bulkiness of the equipment (the total length of the installation can reach 30-35 m), the difficulty of lowering two cables simultaneously into the well, in addition, due to the presence of two cables, the probability of insulation failure and failure of the installation increases, The issues of studying separated formations have not been resolved. Also, this installation does not allow the use of various combinations of electric motors and pumps, since their standard sizes are incorporated in the manufacture.

Closest to the technical nature of the proposed installation is a "Pump installation for simultaneous separate operation of two layers in the well" (patent RU No. 2291953, IPC ЕВВ 43/14, 47/00, publ. 20.01.2007. Bull. No. 2), containing a column of elevator pipes, a cable, a packer, a liner and two separate pumps for pumping out the formation products, which are enclosed in the upper and lower shells, the pump for pumping out the products of the lower layer being made electric submersible, while the lower casing of the electric submersible pump is equipped with a cable sealing unit and a message n from the bottom with the under-packer space through the liner, which is above the packer equipped with a bypass device capable of providing hydraulic communication between the over-packer space of the well and its under-packer space through the liner when the pressure of the bypass device is reached in the well, the outlet of the electric submersible pump communicating with the upper casing with a column of elevator pipes and provided with a lateral channel, while the upper pump is made by a rod, the column of rods of which is made polo and sealingly connected with plunger sucker rod pump, the intake of the pump through a side channel in communication with the space nadpakernym and submersible pump from the bottom it may be equipped with a pressure sensor adapted to transmit via cable submersible pump information.

The disadvantages of this installation are:

- the constructive impossibility of using an plug-in plunger pump, which complicates the process of extracting and repairing this pump (this is possible only with a column of elevator pipes);

- the lifting of hollow rods and columns of elevator pipes cannot be carried out without spilling the liquids contained in them, which worsens the working conditions of the service crews;

- the impossibility of pumping reagents into the lower layer and flushing the annulus under the packer without removing the installation from the well.

The technical task of the invention is to provide the possibility of alternating operation of the pumps and the possibility of using an plug-in plunger pump due to the installation of valves in the side channel of the upper casing and between the column of elevator pipes and the outlet of the electric submersible pump to simplify installation and maintenance of the installation, as well as to exclude the possibility of spilling liquid when lifting pumps, providing preliminary drainage of fluid into the well, the expansion of functionality at the same time due to the possibility of reagent injection in the lower layer and flushing annulus under the packer without removing the installation from the well.

The technical problem is solved by a downhole pumping unit for simultaneous separate operation of two layers containing a lift pipe string, a cable, a packer installed between the beds, a transfer device, an upper one enclosed in a casing — a plunger with a rod string and a lower one communicating with the under-packer space — electric submersible with an electric motor, pumps for pumping the products of the corresponding layers, a cable sealing unit, while the output of the electric submersible pump is communicated by a pipe with an upper casing, which is on top communicated with the column of elevator pipes and provided with a side channel communicating the input of the upper pump with nadpakernym space.

New is that the upper casing is made in the form of a sleeve with an additional longitudinal channel, equipped with a technological pipe mounted on top of the upper casing and communicated from above with an elevator pipe string, and from the bottom with a side channel that is equipped with a safety non-return valve, and a pipe communicating the outlet the lower pump with a column of elevator pipes through the longitudinal channel of the upper casing, is also equipped with an additional check valve, above which a bypass device and a packer with a hermet assembly are placed in series cable, and the plunger pump is made plug-in with the possibility of tight interaction with the inner surface of the technological pipe of the upper casing, and the additional valve is equipped with side bypass channels with adjustable valves that open when the pressure in the check valve is higher than the set pressure, while the packer is set below the set pressure for adjustable check valve valves.

Figure 1 - the upper part of the installation with the upper layer.

Figure 2 - the lower part of the installation with the lower layer and the packer.

A downhole pump installation for simultaneous separate operation of two layers, containing a column of elevator pipes 1 (Fig. 1), cable 2, packer 3 (Fig. 2) with a sealing unit 4 of cable 2 (shown in Fig. 2 conventionally) installed between the upper 5 (Fig. 1) and lower 6 (Fig. 2) layers, a bypass device 7 (for example, in the form of a knock-off valve or pressure-destructible membrane not shown in the drawing), the upper 8 (Fig. 1) enclosed in a casing 9, - plunger with a column of rods 10 and lower 11 (figure 2), communicated with the under-packer space 12, - electric submersible with electric pump 13 for pumping the products of the corresponding layers 5 (Fig. 1) and 6 (Fig. 2), the output of the electric submersible pump 12 is communicated by a pipe 14 with an upper casing 9 (Fig. 1), which is connected from above to the column of elevator pipes 1 and equipped with a side channel 15, which communicates the input of the upper pump with puffer space 16. The upper casing 9 (Fig. 1) is made in the form of a sleeve with a side 15 and longitudinal 17 channels, equipped with a process pipe 18 fixed on top of the upper casing 9 and communicated from above with the lift column pipes 1, and bottom with side channel ohm 15, which is equipped with a safety non-return valve 19. A pipe 14 communicating the output of the lower pump 11 (Fig. 2) with a column of elevator pipes 1 (Fig. 1) through the longitudinal channel 17 of the upper casing 9 is also equipped with an additional non-return valve 20 (Fig. 2) , above which the bypass device 7 and the packer 3 with the sealing unit 4 of the cable 2 are placed. The plunger pump 8 (FIG. 1) is made plug-in with the possibility of tight interaction with the inner surface of the technological pipe 18 of the upper casing 9. The additional valve 20 (FIG. 2) is equipped side p repusknymi channels 21 with adjustable valves (for example, spring-loaded valves with adjustable spring - not shown) which open when the pressure in the check valve 20 installed above. Packer 3 set pressure is lower than that set for check valves 20.

Downhole pumping unit for simultaneous separate operation of two layers works as follows.

When assembling the installation, depending on the productivity and depth of the lower formation 6 (Fig. 2), the pump 11 is selected (the higher the productivity of the formation, the more productive the pump 11 should be) and its electric motor 13 (the deeper the interval of occurrence of the formation 5, the more powerful it should be an electric motor 13). After that, the selected pump 11 with the electric motor 13 and cable 2, the installation is assembled sequentially, lowering into the well 22, while cable 2 is passed through the sealing unit 4 of the packer 3 with subsequent insulation (for example, using an elastic sleeve clamped by a hollow nut - in FIG. 2 not shown).

The assembly without the plunger pump 8 is lowered down the pipe string 1 into the well 22 until the packer 3 is placed with the sealing unit 4 and the anchor unit 23 (for example, P-EGM-188/122 with a landing pressure of 8 MPa, manufactured by NPO Packer, Oktyabrsky) between layers 5 (figure 1) and 6 (figure 2). To install the packer 3 in the column of elevator pipes, landing pressure is created due to the retention of pressure in the check valve 20 (for example, KOT-93, manufactured by NPO Packer, Oktyabrsky, with a pressure set to open the adjustable valves 9.0-15.0 MPa bypass channels 21, which is higher than the packer landing pressure 3). Then, the installation is unloaded to the packer 3, additionally compressing the packer 3 and jamming the anchor 23. Then, the plug-in plunger pump 8 is lowered into the column of lift pipes 1 (Fig. 1) on the column of rods 10 until it tightly interacts with the inner surface of the process pipe 18. Then the mouth equipped with wellhead fittings (not shown) with sealing of the cable outlet and with the possibility of longitudinal movement of the column of rods 10. The column of rods 10 is attached to the wellhead drive (for example, a rocking machine - not shown in figure 1), and cable 2 to -governing substation (not shown in the drawing).

To start the installation, a voltage is applied via cable 2, under the action of which the electric motor 13 (FIG. 2) is driven, the rotor of the pump 11 is rotated. As a result, the products of the lower layer 6 from the sub-packer space 12 are fed to the input of the lower pump 11, which pumps the incoming products through the pipe 14 through an additional valve 20 and a longitudinal channel 17 (Fig. 1) of the upper casing 9 into the lift pipe string 1.

In this case, the column of rods 10 with the help of the drive give a reciprocating movement, which is transmitted to the plunger 24 of the upper pump 8. As a result, the production of the upper layer 5 from the over-packer space 16 through the side channel 15 and the safety valve 19 enters the process pipe 18 and the input of the upper pump 8, which pumps this product into the column of elevator pipes 1, where it is mixed with the products of the lower layer 6 (figure 2).

According to the tubing string 1 (FIG. 1), the production of the layers 5 and 6 (FIG. 2) by means of the corresponding pumps 8 (FIG. 1) and 11 (FIG. 2) is understood to the surface.

When starting the installation, it is recommended to first start the lower pump 11 to raise the liquid level inside the column of lift pipes 1 (Fig. 1), to create a pressure differential with the over-pack space 16 of the well 22, which additionally fixes the upper pump 8 in the process pipe 18.

In cases of failure (unauthorized removal) of the upper pump 8 (Fig. 1) from the process pipe 18 or when removing the upper pump 8 for prevention, repair or replacement (so, the life of the plunger pumps is lower than the electric submersible ones), the safety valve 19 eliminates the ingress (crushing) of liquid from the columns of the lift pipes 1 through the lateral channel 15 and the over-packer space 16 into the upper layer 5, since in the column of the lift pipes 1 the liquid level supported by the pumps 8 and 11 (FIG. 2) is higher than the hydrostatic pressure of the upper layer 5 (FIG. 1). In this case, the production of the lower formation 6 (Fig.2) by the lower pump 10 can continue after sealing the wellhead 22.

To clean the annular - nadpakerny space 16 (figure 1) of the well 22 and pumping the reagents into the upper layer 5, the pumps 8 and 11 (figure 2) are previously stopped. Then, to clean the over-packer space 16 (Fig. 1), the plunger pump 8 on the rod string 10 is lifted up to exit the process pipe 8, a liquid is pumped through the annular space 16, which, circulating through the safety check valve 19 and the lift pipe string 1, cleans the over-packer space 16, and for the injection of reagents into the formation 5, the column of elevator pipes 1 is sealed and the reagents are pumped through the annulus 16 directly into the upper formation 5.

To clean the annular - under-packer space 12 (FIG. 2) of the well 22 and pump the reagents into the lower layer 6, the pumps 8 (FIG. 1) and 11 are previously stopped. Then, for injection of reagents into the lower layer 6 (Fig. 2), they are supplied through the column of elevator pipes 1 (Fig. 1) under a pressure higher than that set for opening the adjustable valves of the bypass channels 21 (Fig. 2) of the non-return valve 20. Thus, the reagents are pumped along the under-packer space 12 directly into the lower formation 6, and for cleaning the under-packer space 12, the injection of fluid is alternated similarly to the injection of reagents into the formation 6 and its pumping out by the lower pump 11.

During operation, if necessary, any of the pumps 8 (figure 1) or 11 (figure 2) can be stopped, while the other pump 11 or 8 (figure 1) can work in normal mode, due to the presence of check valves 19 and 20 (figure 2).

To remove the installation from the well 22 (Fig. 1), the plunger pump 8 is first removed on the rod string 10, then the lift pipe string 1 is pulled upwards, depressurizing the packer 3 (Fig. 2) and releasing the anchor 23, which is equipped with a load. By removing the anchor, the cargo is released and destroys the relief valve of the bypass device 7 for draining the liquid from the column of elevator pipes 1 (Fig. 1) when lifting the unit from the well 22. If the bypass device 7 (Fig. 2) is made with a membrane (not shown in the drawing), then the column of elevator pipes 1 (Fig. 1) is sealed, and pressure is created in its annulus destroying the membrane 7 for draining the liquid from the column of elevator pipes 1 (Fig. 1) when the installation is lifted from the well 22.

In cases where emergency situations are possible when removing the packer 3, the pipe above the packer 3 is equipped with a detachable sleeve 24 (Fig. 2), disconnected by pressure (for example, MRG-89 with a disconnection pressure of 5.0 MPa after discharge from the ball mouth, produced NPO "Packer", Oktyabrsky) or with the help of a load (for example, in the form of telescopic tubes fixed with a shear element designed for a load of 100-120 kN failure - not shown in the drawing). After disconnecting the clutch 24, the load is discharged, which destroys the relief valve of the bypass device 7. Then a fishing device (not shown) is lowered to remove the packer 3 with pump 11 from the well 22.

Between the electric motor 13 and the pump 11, it is possible to install a hydraulic protection 25 (Fig. 2 is shown conventionally).

To equalize the pressure inside and outside the nozzle 14 (Fig. 2) during depressurization of the packer 3 above the packer 3, a balancing valve can be installed on the nozzle 14 (for example, KUM-112 with an operating load of 1-6 tons, manufactured by NPO Packer, Oktyabrsky - not shown in Fig. 2), opening with a tensile force less than the removal force of the packer 3.

The proposed design of the well installation provides the possibility of alternating operation of the pumps and the possibility of using an plug-in plunger pump due to the installation of valves in the side channel of the upper casing and between the column of elevator pipes and the outlet of the electric submersible pump to simplify installation and maintenance of the installation, as well as to exclude the possibility of liquid outflow when lifting the pumps, providing preliminary drainage of fluid into the well, while expanding functional capabilities due to the possibility of reagent injection the lower layer and washing the annulus below the packer from the well without removing the installation.

Claims (1)

A downhole pumping unit for simultaneous separate operation of two layers, comprising a column of elevator pipes, a cable, a packer installed between the layers, a transfer device, an upper plunger enclosed with a casing of rods and a lower pump submersible with an electric motor for pumping out the products of the corresponding layers, cable sealing unit, while the output of the electric submersible pump is communicated by a pipe with an upper casing, which is connected to the column of elevator pipes from above and equipped with a side channel that communicates the input of the upper pump with puffer space, characterized in that the upper casing is made in the form of a sleeve with an additional longitudinal channel, equipped with a process pipe mounted on top of the upper casing and communicated from above with the pipe tubing, and from the bottom with the side channel, which is equipped with a safety non-return valve, and a pipe that communicates the output of the lower pump with the column of elevator pipes through the longitudinal channel of the upper casing is also equipped with an additional non-return valve above which a bypass device and a packer with a cable sealing assembly are arranged sequentially, the plunger pump being plug-in capable of tightly interacting with the inner surface of the technological pipe of the upper casing, and the additional valve is equipped with side bypass channels with adjustable valves that open when the pressure in the check valve rises above set, while the packer landing pressure is lower than that set for the non-return valve adjustable valves.

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