RU2649158C2 - Borehole electrohydraulic pump unit - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: installation includes a kinematically connected submersible electric motor, a drive pump and a hydraulic motor, and a working pump with a discharge and suction valves. Additionally contains a flow divider and a mechanical switch. The drive pump, the flow distributor, the flow divider, the mechanical switch linked with the hydraulic cylinder rod, and all of these units are located in a cylindrical housing filled with oil. The submersible motor is connected to the drive pump by means of a coupling and has a common oil system with hydraulic protection.

EFFECT: higher efficiency of the low-yield submersible electrohydraulic drive pump unit.

3 cl, 1 dwg

Description

Technical field

The invention relates to pumping systems for oil production from wells, in particular to a reciprocating device having a submersible electric motor (PED) as a drive, and more particularly, to a borehole electro-hydraulic pump installation.

State of the art

In the prior art, a large number of structural designs of pumping units.

From the patent document RU 2105193 C1 of 06/20/1996, a hydraulic drive pump is known, comprising a housing with sealing systems and placed in its cavity with the possibility of reciprocating movement by the working body, as well as lids attached to the ends of the housing, in one of which at least one hole for connecting to the drive hydraulic system, and in the second at least one hole for connecting to the suction and discharge lines, while the pump housing is prefabricated, and the working body represents oboj disc attached to its ends by plungers.

The disadvantages of this design of the pump is the complexity of its manufacture and operation, which is typical for piston pumps. This leads to high cost and a small resource of work. The absence of shock absorbers between the periodically contacting elements of the pump reduces the reliability of its operation. In addition, the device has limited operational capabilities, since its design does not allow the pump to be readjusted to other operating conditions (for example, for supply and pressure).

From the patent document RU 2116512 C1 of 07.27.1998 a well-known electrohydraulic drive pump unit is known containing kinematically connected to each other a submersible electric motor and a drive pump, as well as a working pump with suction and discharge valves, while it is equipped with a hydraulic motor, and the hydraulic motor and working pump each is made in the form of a cylinder and a plunger with a rod, the rods of the plungers are connected to each other, the cavity of the cylinder of the hydraulic motor are connected through the distributor to the input and output of the drive pump, the suction The inlet valve is located in the plunger, and the discharge valve in the upper part of the working pump cylinder, the cylinder and the working pump plunger have openings for receiving the produced fluid, and the unit is equipped with a tank having a volume compensator and connected to the input of the drive pump.

The disadvantage of this device design is that it has a low efficiency characteristic of diaphragm electric pumps, and low reliability due to the frequent failure of the kinematics elements.

As a prototype, the technical solution was selected according to patent document RU 2166668 C1 of 05/10/2001, from which a well-known electro-hydraulic pump unit is known, which contains a kinematically coupled submersible electric motor and a drive pump, a working pump with suction and discharge valves, driven by a hydraulic motor, the cavity of the cylinder of which is connected through the distributor to the inlet and through the safety valve to the output of the drive pump, while the hydraulic motor rod through the tread It is connected with the rod of the working pump, and its body contains front and rear covers, while the unit is equipped with a tank having a volume compensator, in one of the sections of which there is an overflow valve, a flow regulator and a filter, while the tread is made in the form of a flexible sleeve, one the end of which is rigidly fixed on the stem of the hydraulic motor, and the other on its front cover, the hydraulic motor is equipped with a hydraulic brake located in its rear cover and a rod rotation limiter located inside the working body of the hydraulic motor and rigidly fixed on its back cover, the sleeve cavity being connected via a pipeline to the tank.

A disadvantage of the known design is the low efficiency characteristic of diaphragm electric pumps, and low reliability, due to the frequent failure of the kinematics elements.

Disclosure of invention

The purpose of the invention is the creation of a submersible borehole pumping unit with reciprocating action, with higher efficiency relative to installations for wells with low flow rate, as well as improving reliability, increasing the resource and operational capabilities of low-rate submersible electrical installations.

The technical result of the claimed invention is to increase the efficiency of low-rate submersible electro-hydraulic pumping units.

The claimed technical result is achieved due to the fact that the borehole electrohydraulic pumping unit includes kinematically interconnected submersible electric motor (PED) with hydraulic protection, a drive pump and a hydraulic motor, as well as a working pump with discharge and suction valves, characterized in that it additionally contains a flow divider and a mechanical switch, and a drive pump, a flow distributor, a flow divider, a mechanical switch associated with the rod Tehnological cylinder, and all the nodes are arranged in a cylindrical housing filled with oil, wherein the submersible motor pump is connected to a drive via a clutch and a hydraulic oil system overall protection.

The coupling is slotted. The case is a tank.

The cylinder and plunger of the working pump have a suction and discharge / safety valves.

The pump unit has a tank with an oil volume and pressure compensator, which is connected to the input of the drive gear pump.

The drawing shows a General view of a borehole electrohydraulic pumping unit,

Where

1 - submersible electric motor (SEM) with hydraulic protection (G / Z)

2 - drive pump

3 - distributor of a stream of a working fluid

4 - flow divider

5 - mechanical switch

6 - technological hydraulic cylinder (TGC)

7 - working plunger pump

8 - tank

9 - discharge pipe

10 safety / discharge valve

11 - suction valve

A volumetric drive pump (for example, a gear pump) ensures uninterrupted operation of the pump unit.

The flow divider provides the alignment of the speed of the rod of the technological cylinder, both in forward and reverse motion.

A mechanical switch is required to redirect the flow of working fluid through the dispenser.

The process hydraulic cylinder (TGC) serves as a double-stroke hydraulic lift.

A working plunger pump provides the rise of well fluid along the tubing string (tubing), on which the entire electric drive pumping unit is suspended.

A submersible electric motor PED (1) is connected by a spline coupling to a drive pump (2). Submersible electric motor (SEM) with hydraulic protection have a common oil system, which is filled with synthetic oil directly designed for these engines.

Hydraulic protection is designed to protect against penetration of formation fluid into the internal cavity of submersible asynchronous oil-filled electric motors, to compensate for oil leaks and thermal changes in its volume during operation and shutdowns, as well as to transmit torque of the motor shaft to the pump shaft.

Protectors of the PA type are single-case hydroprotection without compensation and are intended for the assembly of motors of the PED series with housing diameters of 103, 117, 130 mm, with right and left rotation of the shaft, manufactured according to TU 3381-001-93436026-2006, and other electric motors with the corresponding overall , connecting dimensions and technical specifications.

Surfactant-type protectors are double-case hydroprotections, consisting of a surfactant protector and KAV compensator, and are intended for the assembly of engines of the PEDV series with a housing diameter of 103, 117, 130 mm, with left-hand rotation of the shaft, manufactured according to TU 3381-001-93436026-2006, designed for individual mechanized pumping of water from reservoir to reservoir (inverted type plants).

PAD type protectors are single-case hydroprotections designed to complete the engines of the PEDD series (with two-sided shaft output) with a housing diameter of 103, 117, 130 mm, with right and left shaft rotation, manufactured according to TU 3381-001-93436026-2006, designed for installations with two pumps. With this configuration, the torque to the main pump (located above the electric motor) is transmitted through the protector type PA, the torque to the booster pump (located below the electric motor) is transmitted through the protector type.

Above the drive pump (2) there is a distributor of the working fluid flow (3), a flow divider (4), a mechanical switch 5 kinematically connected to the rod of the process cylinder (6), and all of the above structural units are placed in a cylindrical body (pipe) with a diameter of 103 mm , which is a tank 8, filled with oil having the highest viscosity, for operation in conditions of high temperature of the well (up to + 230 ° C). The output link of the electro-hydraulic pumping unit is a THC rod with a stroke length of 1200 mm.

The inlet of the drive pump is located directly in the tank housing, which ensures unhindered oil supply. The discharge pipe (9) passes inside the tank housing from the drive pump (2) to the distributor of the working fluid flow (3) and is connected to the safety valve (10), the outlet opening of which goes into the oil-filled cavity of the tank housing.

The distributor of the flow of the working fluid (3) is connected via pipelines to the upper and lower cavities of the THC (6), and the pipeline going to the upper cavity of the THC (6) passes through the flow divider 4.

The stem of the TCC 6 at the outlet is mechanically connected to the plunger of the working pump (7), which has a suction valve in the movable part of the plunger and a discharge valve in the upper part of the pump. The plunger of the working pump is located in the cylinder, in the lower part of which there are openings for receiving the produced fluid. A suction valve is installed inside the plunger, and a discharge valve is installed at the top of the cylinder.

The electro-hydraulic pumping unit is connected by screwing to the tubing, on which the equipment is lowered into the well.

Electrical support for the SEM occurs through a cable (type KPBP), the coupling of which is directly hermetically connected to the electric motor of the SEM, and the cable lowered with the installation is attached to the tubing string using clamps (not shown).

Electrohydraulic pumping unit operates as follows.

When the pump unit is immersed in the well, the formation fluid fills the lower cavity of the working plunger pump (7) through the inlet openings. As the unit is lowered into the working zone of the well, the hydrostatic pressure in the lower part of the working plunger pump (7) increases and under its action both suction and pressure valves open and the formation fluid fills not only the cavity of the working pump (7), but also the pump compressor pipes (tubing) to a level directly proportional to the pressure of the wellbore.

When the PED electric motor (1) is started, the drive pump (2) starts to work, which through the distributor (3) delivers the oil under high pressure to the lower cavity of the THC (6). The THC piston (6) begins to move upward, displacing the oil from its upper cavity; oil through the pipeline through the distributor (3) enters the casing-tank of the installation and then directly to the inlet of the drive pump (2). The difference between the volumes of oil injected and displaced in the THC is determined by the presence of a rod of a larger diameter than in the lower part, and is compensated by a flow divider (4).

Moving the piston TGC 6 upwards forces the plunger of the working pump 7 to move upward through a mechanically connected rod of one and the other pumps, while the formation fluid is injected from the upper cavity of the working pump 7 through the discharge valve into the tubing, while the lower cavity of the working pump is filled formation fluid through a suction valve.

When the THC piston (6) reaches its upper point, the flow distributor (3) switches over with a mechanical switch (5) and the mechanically connected plunger of the working pump (7) and the THC piston (6) return. When the piston ТГЦ (6) reaches its lower position, the distributor (4) switches back and the duty cycle is repeated.

The claimed downhole electric hydraulic pumping unit can be used in the oil industry for lifting oil from vertical and directional wells with complicated operating conditions.

To work at high temperatures in "hot" wells up to 230 ° C, the oil used to lubricate the hydraulic cylinders driven by steam was chosen as the working fluid. The kinematic viscosity of this oil according to the data is 60-70 cSts (centistokes) at 100 ° C. No analogue of him or superior to him in kinematic viscosity was found.

The borehole electro-hydraulic pumping unit meets the requirements of safety and industrial sanitation, as its operation is carried out at a depth in the well away from the staff.

Claims (3)

1. A borehole electrohydraulic drive pump installation, including a kinematically interconnected submersible electric motor (PED) with hydraulic protection, a drive pump and a hydraulic motor, as well as a working pump with discharge and suction valves, characterized in that it further comprises a flow divider and a mechanical switch, and a drive pump, a flow distributor, a flow divider, a mechanical switch associated with the rod of the process hydraulic cylinder, and all of these nodes are located in an oil-filled cylindrical housing, wherein the submersible motor is connected to the drive pump by means of a coupling and has a common oil system with hydraulic protection. 2. Installation according to claim 1, characterized in that the clutch is spline. 3. Installation according to claim 1, characterized in that the housing is a tank.

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