Hydraulic drive for sucker rod pump (variants)

Abstract

A hydraulic drive for a sucker rod pump comprises an oil station, and a single-acting hydraulic cylinder having a hollow piston and a hollow rod which together form a medium separator, the lower part of the rod containing at least one hole and being designed to be connectable to a rod string.

Description

[0001] F04B 47 / 04

[0002] Hydraulic drive of the sucker rod pump (options)

[0003] The invention relates to oil production equipment and is intended to drive a sucker rod pump used for extracting formation fluid from wells.

[0004] A known oil production device is equipped with a pumping unit (see patent RU2672241, dated November 12, 2018). It includes a frame, a thrust support connected to the base, a hydraulic cylinder, an oil pump, articulated crossbars, and a control station. Disadvantages include complexity and low operational reliability, bulkiness, high metal requirements, and labor-intensive installation.

[0005] A device in the form of a hydraulic drive for a sucker rod pump (see patent RU133572, dated October 20, 2013) is known. It comprises a hydraulic cylinder, piston, piston rod, hydraulic tank, electric motor, pump-motor, control system, and an internal combustion engine. This known solution offers good functionality, allowing the sucker rod pump to operate during power outages and to heat the shelter using exhaust gases from the internal combustion engine. Disadvantages of this known technical solution include its non-environmental design due to the presence of an internal combustion engine, the potential for oil contamination of the ground surface in the event of a leak, and the increased metal consumption.

[0006] The closest technical solution is the Geyser-type sucker-rod pump hydraulic drive (see Engineering Practice magazine, issue No. 04 / 2015, June 29, 2015, article "Hydraulic Drives for Sucker-Rod Well Pumps," pp. 42-47), which comprises a support mast, a hydraulic cylinder with a piston and rod, and an oil station with an electronic control system. The disadvantages of this known solution, the design of which is used as a prototype in this application, include bulkiness, high metal consumption, increased labor costs during installation and subsequent maintenance, and low efficiency.

[0007] The objectives of the proposed technical solution are to eliminate the shortcomings of known technical solutions, improve operational characteristics such as efficiency and environmental friendliness, reduce weight and size indicators, increase the reliability of the design, and enable application for various types and operating conditions.

[0008] The stated problem is solved by creating a hydraulic drive for a sucker-rod pump containing an oil station, a single-acting hydraulic cylinder including a piston with a rod, the hydraulic cylinder contains upper and lower covers, wherein in order to form a separator separating oil and petroleum, the piston and rod are made hollow with the possibility of oil passage, the rod cavity of the hydraulic cylinder is connected to the oil station, between the hollow piston and the wall of the hydraulic cylinder, and also between the lower cover and the hollow rod, oil scraper elements are located, wherein the lower part of the rod contains at least one hole and is made with the possibility of connection with a column of rods.

[0009] A hydraulic drive for a sucker rod pump in which the lower part of the rod contains a perforated section.

[0010] The stated problem is also solved by creating a hydraulic drive for a sucker-rod pump containing a programmable oil station, a single-acting hydraulic cylinder with a piston and a rod, the hydraulic cylinder contains upper and lower covers, while in order to form a separator separating oil and petroleum, the piston and rod are made hollow with the ability to pass oil, the rod cavity of the hydraulic cylinder is connected to the oil station, between the hollow piston and the wall of the hydraulic cylinder, and also between the lower cover and the hollow rod, oil scraper elements are located, and the lower part of the rod contains a perforated section, as well as a thread at the end for connection to the rod column.

[0011] The hydraulic drive of the sucker rod pump contains a power branch pipe located in the upper part of the hydraulic cylinder.

[0012] The hydraulic drive of the sucker rod pump contains a check valve built into the top cover of the hydraulic cylinder.

[0013] The essence of the invention is revealed in the figures and in the description.

[0014] Fig. 1 - Hydraulic drive of a sucker rod pump with a lower piston position in an external design;

[0015] Fig. 2 - Hydraulic drive of a sucker rod pump with an upper piston position in an external design;

[0016] Fig. 3 - Hydraulic drive of a sucker rod pump with a lower piston position in an internal design;

[0017] Fig. 4 - Hydraulic drive of a sucker rod pump with an upper piston position in an internal design. Fig. 1 shows a hydraulic drive of a sucker-rod pump with a lower position of piston 3, containing an oil station 1, a single-acting hydraulic cylinder 2, a hollow piston 3, a hollow rod 4, holes 5 forming a perforated section and formed in the wall of the hollow rod 4. The hydraulic cylinder 2 contains an upper cover 6 and a lower cover 7. A check valve 8 is built into the upper cover 6. The hollow rod 4 passes through the lower cover of the hydraulic cylinder 7. The hydraulic cylinder 2 is divided by the hollow piston 3 into two cavities - rod cavity 9 and piston cavity 11, the volume of which can change depending on the working position of the hollow piston 3. Rod cavity 9 of the hydraulic cylinder 2 is connected by means of an oil pipeline 10 to the oil station 1, which supplies oil under pressure into rod cavity 9 to move the hollow piston 3 to the top position.The piston cavity 11 of the hydraulic cylinder 2 is connected on one side with the cavity 12 of the hollow rod 4, and on the other side through the check valve 8 by means of the power branch pipe 13 with the oil collection manifold 14. The piston cavity 11 of the hydraulic cylinder 2 is filled with oil during the working cycle. In the lower position of the hollow piston 3, the volume of the rod cavity 9 of the hydraulic cylinder 2 is less than the volume of the piston cavity 11. The hollow rod 4, for example, by means of a threaded connection, is connected to the string of rods 15, on which the sucker rod pump 16 is mounted. The string of rods 15 is placed in the cavity 17 of the tubing pipes 18, which are enclosed in the casing production string 19 located in the well. To tie the wellhead in order to seal the connections, as well as to suspend the casing columns on the ground surface, a column head 20 is installed.For vertical fixation of hydraulic cylinder 2 and hollow rod 4, crosspiece of column head 21 and upper flange 22 installed on column head 20 are used. Between hollow piston 3 and wall of hydraulic cylinder 2, as well as between lower cover 7 and wall of hollow rod 4, oil scraper elements 23 are located, preventing oil from entering from rod cavity 9 into piston cavity 11 and into cavity 17 of tubing 18. The shown arrangement is used with external placement of hydraulic drive, in which all its elements are located at the wellhead and are easily accessible for maintenance. At great oil depths, where electric driven centrifugal pumps and pumping units are ineffective, by increasing the piston diameter it is possible to increase the power of hydraulic drive several times, which will allow production from great depths (up to 8000 meters).

[0018] Fig. 2 shows the hydraulic drive of a sucker-rod pump with the hollow piston 3 in the upper position. Due to the pressure created by the oil station 1 on the hollow piston 3, the hollow rod 4, the rod string 15 connected to it by a threaded connection, and the sucker-rod pump 16 are in the upper position. The volume of the rod cavity 9 of the hydraulic cylinder 2 is completely filled with oil. The check valve 8 is in the open position.

[0019] Fig. 3 shows the internal arrangement of the hydraulic drive of a sucker rod pump containing an oil station 1, a single-acting hydraulic cylinder 2, a hollow piston 3, a hollow rod 4, holes 5 that form a perforated section and are formed in the wall of the hollow rod 4. The hydraulic cylinder 2 contains an upper cover 6 and a lower cover 7. A check valve 8 is built into the upper cover 6. The hydraulic cylinder 2 is divided by the hollow piston 3 into two cavities: a rod cavity 9 and a piston cavity 11, the volume of which can change depending on the operating position of the piston 3. The oil station 1 is connected to the rod cavity 9 by means of an oil pipeline 10, wherein part of the oil pipeline 10 is made in the form of a jacket 24, which is a chamber surrounding the hydraulic cylinder 2. The jacket 24 is connected to the rod cavity 9 by means of holes in the body of the hydraulic cylinder 2.The illustrated arrangement is used for internal hydraulic drive placement, in which the hydraulic cylinder 2, hollow piston 3, and hollow rod 4 are housed within the column head 20, which protects the hydraulic drive components from external influences, such as sea currents when the unit is installed offshore. Furthermore, in the event of an emergency caused by failure of structural components, no oil spill or pollution occurs; the oil flows back into the well, enhancing the environmental friendliness of this hydraulic drive design. Another advantage of the illustrated arrangement is the lack of additional structures to secure the unit, reducing labor costs during installation during offshore field development.

[0020] Fig. 4 shows the internal arrangement of the hydraulic drive of the sucker rod pump with the upper position of the hollow piston 3. Due to the pressure created by the oil station 1 on the hollow piston 3, the hollow rod 4, the column of rods 15 are in the upper position as close as possible to the upper cover 6 of the hydraulic cylinder 2. The check valve 8 is in the open position.

[0021] The hydraulic drive of the sucker rod pump operates cyclically. Oil station 1 supplies oil through oil line 10 to rod cavity 9 of hydraulic cylinder 2 under the pressure necessary to move hollow piston 3 to the upper position. Hollow piston 3, rising upward, pulls hollow rod 4 and the string of rods 15 fixed to it, activating sucker rod pump 16. Sucker rod pump 16, moving upward, takes a certain amount of oil from the oil reservoir, which enters cavity 17 of tubing 18. After piston 3 reaches the upper position, oil station 1 reduces the oil pressure in oil line 10 to a value at which piston 3 begins to descend under the weight of the rods to its lower position. In this case, oil is displaced from cavity 9 back into the hydraulic tank of oil station 1. Then the cycle is repeated.Oil rises through cavity 17 and after a certain number of cycles reaches holes 5 made in a circular shape and forming a perforated section in the hollow rod 4 and passing through them enters cavity 12 of the hollow rod 4, passes the hollow piston 3, after which it enters the piston cavity 11 of the hydraulic cylinder 2, from which through the open check valve 8 and the power branch pipe 13 it enters the oil collection manifold 14. Thus, in the process of pumping from the oil reservoir to the manifold, oil passes through a separator formed by the hollow piston 3 and the hollow rod 4 with holes 5 forming a perforated section located in the lower part of the hollow rod 4. The lower part of the hollow rod 4 made in the form of a perforated section uniformly passes oil through itself, which improves its passage from the cavity of the tubing 17 into the cavity 12 hollow rod 4.At the moment of movement of the hollow piston 3 downwards, the check valve 8 is closed, thus the oil located in the power pipe 13 and the oil collection manifold 14 does not flow back into the cavity 11 of the hydraulic cylinder 2, which increases the efficiency of the hydraulic drive and the speed of oil pumping.

[0022] The proposed technical solution differs structurally from known technical solutions in that it uses a separator consisting of a hollow piston 3 and a hollow rod 4 with holes 5 forming a perforated section, allowing the produced oil to pass through the hydraulic cylinder. This solution reduces metal consumption and lowers the cost of the design. The proposed design is more environmentally friendly because the oil flow is contained within the cylinder. In the event of piston seal failure, the oil will flow back into the well rather than spilling onto the surface. The hydraulic drive of the proposed design can be mounted either inside the well or externally, at the wellhead, preventing environmental degradation and eliminating oil and grease spills.

[0023] The software control of oil station 1 allows you to set the operating parameters of the hydraulic drive of the sucker rod pump, for example, the operating speed and the stroke and number of oscillations of the hollow piston 3.

[0024] The proposed sucker rod pump drive has a relatively simple design, simplifying maintenance and repair. It can be used in various climatic conditions, under strong wind loads, and offshore due to the ability to house the main drive components within the column head.

[0025] Thus, the proposed hydraulic drive for sucker rod pumps meets modern requirements:

[0026] - has a simple design,

[0027] - has high reliability,

[0028] - has a low mass while producing high lift,

[0029] - does not require a special foundation,

[0030] - ensures easy installation and maintenance.

Claims

Formula 1. A hydraulic drive for a sucker-rod pump, comprising an oil station, a single-acting hydraulic cylinder including a piston with a rod, characterized in that the hydraulic cylinder comprises an upper and lower cover, wherein in order to form a separator separating oil and petroleum, the piston and rod are made hollow with the ability to pass oil, the rod cavity of the hydraulic cylinder is connected to the oil station, oil scraper elements are located between the hollow piston and the wall of the hydraulic cylinder, as well as between the lower cover and the hollow rod, wherein the lower part of the rod contains at least one opening and is made with the ability to connect to a column of rods.

2. A hydraulic drive for a sucker rod pump according to claim 1, characterized in that the lower part of the rod contains openings that form a perforated section.

3. A hydraulic drive for a sucker-rod pump, comprising a programmable oil station, a single-acting hydraulic cylinder including a piston with a rod, characterized in that the hydraulic cylinder comprises an upper and lower cover, wherein in order to form a separator separating oil and petroleum, the piston and rod are made hollow with the ability to pass oil, the rod cavity of the hydraulic cylinder is connected to the oil station, between the hollow piston and the wall of the hydraulic cylinder, and also between the lower cover and the hollow rod, oil scraper elements are located, wherein the lower part of the rod contains a perforated section, as well as a thread at the end for connection to a column of rods.

4. A hydraulic drive for a sucker rod pump according to paragraphs 1 or 3, characterized in that it contains a power branch pipe located in the upper part of the hydraulic cylinder.

5. A hydraulic drive for a sucker rod pump according to paragraphs 1 or 3, characterized in that it contains a check valve built into the upper cover of the hydraulic cylinder."

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