RU2347064C2 - Hydraulic sucker-rod submersible pump drive - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil engineering and is duty for conventional pump jack in oil production. It provides lower metal consumption, height overall dimensions, ensures vertical axial stability and ecological safety of the device. The device contains plunger hydraulic cylinder forming under-plunger space and moving it upwards under excess pressure of working liquid and pulling it down under weight of pump rod column when pressure released in under-plunger space. Besides, the device accommodates lift string containing the specified executive section of the hydraulic drive, and working liquid feed pump under excess pressure. According to the invention executive section of the hydraulic drive is provided with central tube supplying working liquid into under-plunger space. As plunger pulled down, this working liquid is ejected through the same tube. Wellstream transportation channel represents annular gap between hydraulic cylinder and lift string. Moreover, vertical axial stability of executive section of the hydraulic drive is ensured with its arrangement on the wellhead below the hanger of downhole equipment.

EFFECT: lower metal consumption, height overall dimensions, ensures vertical axial stability and ecological safety of the device.

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Description

The invention relates to the field of petroleum engineering and is intended to drive a sucker rod pump instead of a rocking machine during oil production.

The aim of the invention is to reduce the metal consumption, height dimension, the creation of vertical axial stability and the preservation of environmental cleanliness.

Known deep-well pumping unit operating from a hydraulic drive [1], in which the actuator is located above the wellhead. A hydraulic actuator, trapped in the lower part and free above, in the form of a tube arrangement undergoes vibration during the operation of the pump unit, which drastically reduces the overhaul period of its operation. This drawback, supplemented by the presence of stuffing boxes or rubber seals, practically makes the hydraulic drive inoperative.

The closest in technical solution to the proposed hydraulic drive is a downhole hydraulic pump installation [2]. It consists of a submersible unit installed in the lifting pipes, and includes two cylinders of different diameters and two plungers connected by a hollow rod and installed in the cylinders with the formation of a superplunger space in the cavity of the lifting pipes, disconnected from the annular space. A load is connected to the plungers, which equalizes the hydrostatic pressure in the lifting pipes with the hydrostatic pressure in the annular space. The installation operates from a hydraulic drive in the form of a power pump connected to an annular space.

The device has the following disadvantages. As a cargo, as a rule, a tubing string is used and it has a length of several hundred meters. When picking cargo from sucker rods, the length will increase by a factor. In directional wells, the movement of such a column during an upward run will complicate the operation of the installation until it is jammed. Reducing the mass of the load will lead to the need to increase the pressure of the power pump, which is also unacceptable due to the action of high pressure on the casing. Given this circumstance, two pipe columns are used in the invention, which greatly increases the metal consumption of the installation.

The technical result of the invention is to reduce the metal consumption, height dimension, the creation of vertical axial stability and the preservation of environmental cleanliness.

The technical result is achieved by the fact that the hydraulic actuator of the sucker rod pump includes

a hydraulic cylinder with a plunger installed with the formation of a sub-plunger space, the ability to move the plunger up under the action of overpressure of the working fluid and lower the said plunger down under the weight of the pump rod string when bleeding pressure in the sub-plunger cavity;

a lifting column, in which said hydraulic actuator executive part is located, and a pump for supplying the working fluid under excessive pressure, the hydraulic actuator having a central channel for supplying the working fluid to the subplunger cavity and forcing this fluid out through the same channel when lowering the plunger down, as The annular gap formed between the hydraulic cylinder and the lifting column serves as the transport channel for the production of the well, while ensuring vertical axial stability. the flax part of the hydraulic drive by placing it on the wellhead below the suspension of the downhole equipment.

The hydraulic actuator consists of the following elements (see drawing). The Executive part of the hydraulic actuator includes two cylinders 1 and 2 of different diameters and a plunger with steps 3 and 4, mounted in the cylinder with the formation of the sub-plunger cavity 5, in communication with the high-pressure region through the hole 6.

The power unit with its control elements consists of a pump 7, a control valve 8, a safety valve 9, a reservoir for the working fluid 10 and a discharge line 11. The plunger part 12 also has a drain line 13. The hydraulic actuator plunger is connected to the borehole pump (not shown) through sucker rod string 14.

An annular gap 15 formed between the hydraulic cylinder 1 and the lifting column 16 serves as a transport channel for the production of wells. The check valve 17 and the gate valve 18 are standard elements of an oil producing well.

The stuffing box device 19 is not designed for a large pressure drop, it is light type and performs only the function of protecting the internal cavity of the hydraulic cylinder from the effects of atmospheric precipitation.

Plunger 3 has a kinematic connection with the control valve 8, which controls an adjustable safety valve, opens and closes it when the piston is raised to the top and bottom dead points.

The hydraulic actuator operates as follows. The pump 7 in the Central channel delivers the working fluid under excess pressure, which is transmitted through the holes 6 in the sub-plunger chamber 5. Upon reaching sufficient force, the plunger assembly begins to move up. When the plunger group reaches the upper position, the working fluid switches to the adjacent pump unit. After bleeding off the pressure from the subplunger cavity, the rod string 14, and with it the plunger 3, spontaneously move downward under their own weight.

In this case, the working fluid from the sub-plunger chamber 5 is displaced into the working tank through the pipe 11. Minor volumes of leakage of the working fluid, if any, without creating a pressure differential at the ends of the upper stage plunger pair along the drain line 13 will be poured into the tank 10.

The produced fluid through the annular gap 15, the check valve 16 with the open valve 17 is fed into the collection system. The overflow clutch 20 pits the gas from the annulus into the pipe by-pass it as its pressure increases.

A positive technical result is achieved due to the absence of the mass of the cargo, the second column for supplying the working fluid to the hydraulic actuator located at the bottom of the well. Most importantly, the hydraulic actuator is located in the wellhead and the power cylinders are below the suspension point of the downhole equipment, which ensures the axial stability of the hydraulic actuator and its vibration-free operation.

Literature

1. Copyright certificate SU No. 245559. IPC Cl. 6 F04B 47/04. Publ. 10/07/1971, bull. No. 10.

2. Copyright certificate RU No. 2107188. IPC Cl. F04B 47/04. Publ. 03/20/1998.

Claims (1)

Hydraulic drive sucker rod pump, including:
a hydraulic cylinder with a plunger installed with the formation of a sub-plunger space, the ability to move the plunger up under the action of overpressure of the working fluid and lower the said plunger down under the weight of the pump rod string when bleeding pressure in the sub-plunger cavity;
a lifting column in which said actuating part of the hydraulic actuator is located;
a pump for supplying the working fluid under excess pressure, characterized in that the hydraulic actuator has a central channel for supplying the working fluid to the subplunger cavity and displacing this fluid through the same channel when the plunger is lowered down, an annular gap serves as a transport channel for producing the well, formed between the hydraulic cylinder and the lifting column, while ensuring vertical axial stability of the Executive part of the hydraulic actuator by placing it at the wellhead below the bottom ski downhole equipment.