A reciprocating rod pump relay load reduction deep pumping device

Abstract

The utility model relates to a reciprocating rod pump relay load reduction deep pumping device, the outer diameter of upper hollow piston rod is less than the outer diameter of lower hollow piston, upper pump cylinder is installed on breathing joint, the lower part of upper hollow piston rod is connected with the upper part of lower hollow piston, the inner hole of upper hollow piston rod and lower hollow piston is drainage channel, upper pump cylinder and breathing joint are sleeved on upper hollow piston rod, lower hollow piston is put into lower pump cylinder, breathing joint is installed on the upper part of lower pump cylinder, the lateral wall of breathing joint has breathing hole, hydraulic feedback pump is composed of mover and stator, the mover is in the stator, the mover can reciprocate in the stator, the lower part of lower hollow piston is combined into an organic whole with the upper part of the mover of hydraulic feedback pump, the lower part of lower pump cylinder is combined into an organic whole with the upper part of the stator of hydraulic feedback pump, lower pump cylinder and hydraulic feedback pump are put into outer pipe, breathing joint is connected in the upper part of outer pipe, the breathing hole is in outer pipe, annular channel is formed between outer pipe and lower pump cylinder and hydraulic feedback pump.

Description

Technical Field

[0001] This invention relates to an oilfield pumping device, specifically a reciprocating rod pump relay unloading deep pumping device. Background Technology

[0002] Reciprocating rod pump oil extraction systems used in oilfields include a pumping unit, sucker rod, pump, and tubing. The pumping unit is installed on the surface, while the sucker rod, pump, and tubing are installed in the wellbore. The pumping unit drives the pump to reciprocate, drawing crude oil from the well to the surface. In deep and ultra-deep wells where reciprocating rod pumps are often used (deep and ultra-deep refer to pumping oil at depths of thousands of meters), the pumping unit, sucker rod, pump, and tubing bear heavy loads. The stroke loss caused by the elastic expansion and contraction of the sucker rod and tubing is significant, as is the leakage between the pump piston and the pump barrel. This results in low pump efficiency and overall system efficiency. Furthermore, problems such as breakage and uneven wear caused by the instability and bending of the lower sucker rod are prominent, and the lifespan of the lower tubing, sucker rod, and pump is short.

[0003] To address this, technicians researched a reciprocating rod pump segmented pumping device. This device installs a hydraulic feedback pump on the tubing and sucker rod between the wellhead and the pumping unit. Well fluid is pumped from the pumping unit to the hydraulic feedback pump, and then from there to the surface. This separates the pressure within the tubing between the wellhead and the pumping unit into two pressure systems. The hydraulic column pressure and load on the tubing, sucker rod, and pumping unit below the hydraulic feedback pump installation position are reduced. During the downstroke, the thrust of the well fluid on the bottom of the sucker rod string is reduced, minimizing stroke loss caused by the elastic expansion and contraction of the sucker rod and tubing below the hydraulic feedback pump installation position. It also reduces the leakage of the pumping unit installed at the bottom of the tubing string, thereby improving pump efficiency and overall pumping system efficiency. Furthermore, it extends the service life of the tubing, sucker rod, and pumping unit below the hydraulic feedback pump installation position. However, this technology requires the theoretical displacement of the hydraulic feedback pump to be greater than that of the oil pump installed at the bottom of the tubing to achieve the above purpose. Therefore, the piston diameter of the hydraulic feedback pump needs to be larger than that of the oil pump, which increases the load on the sucker rod above the hydraulic feedback pump installation position, thus producing adverse effects.

[0004] While the increased load can be mitigated by installing a sucker rod unloading device (such as the sucker rod unloading device in Chinese Patent 2012202957131) on a reciprocating rod pump segmented pumping unit, reducing the load on the sucker rod and pumping unit above its installation location, leakage between the two sets of pistons and the pump barrel in the sucker rod unloading device will reduce well production. Furthermore, the unloading effect of existing sucker rod unloading devices is affected by casing pressure. When the casing fluid level is high, the unloading effect is poor and cannot completely compensate for the increased load. For example, when the casing pressure is at the wellhead (which occurs when the casing is diluted), there is no unloading effect, and the increased load is not compensated for. Summary of the Invention

[0005] The purpose of this invention is to design a reciprocating rod pump relay load reduction deep pumping device, which can reduce the load on the sucker rod above its installation position, overcome the problems existing after installing a reciprocating rod pump segmented pumping device on the tubing string, and reduce the liquid column pressure and liquid column load borne by the tubing, sucker rod and pump below its installation position.

[0006] The objective of this invention is achieved as follows: It includes an upper pump cylinder, an upper hollow piston rod, a breather connector, a lower pump cylinder, a lower hollow piston, and a hydraulic feedback pump. The outer diameter of the upper hollow piston rod is smaller than the outer diameter of the lower hollow piston. The upper pump cylinder is mounted on the breather connector. The lower part of the upper hollow piston rod is connected to the upper part of the lower hollow piston. The inner holes of the upper hollow piston rod and the lower hollow piston are drainage channels. The upper pump cylinder and the breather connector are fitted onto the upper hollow piston rod, and the upper hollow piston rod and the upper pump cylinder cooperate and seal. The lower hollow piston is placed inside the lower pump cylinder, and the lower hollow piston and the lower pump cylinder cooperate and seal. The breather connector is mounted on the upper part of the lower pump cylinder, and the side wall of the breather connector has a breather hole. The breather hole is connected to the lower end of the upper pump barrel and the upper end of the lower pump barrel. The hydraulic feedback pump consists of a mover and a stator. The mover is inside the stator and can reciprocate within the stator. The lower part of the lower hollow piston is integrated with the upper part of the mover of the hydraulic feedback pump. The lower part of the lower pump barrel is integrated with the upper part of the stator of the hydraulic feedback pump. It also includes an outer tube. The lower pump barrel and the hydraulic feedback pump are placed inside the outer tube. The breather connector is connected to the upper part of the outer tube. The breather hole is inside the outer tube. An annular channel is formed between the outer tube, the lower pump barrel, and the hydraulic feedback pump. The upper part of the annular channel is connected to the breather hole, and the lower part of the annular channel is connected to the inlet of the hydraulic feedback pump.

[0007] The beneficial effects of this invention are as follows: This invention is installed on the tubing and sucker rod between the wellhead and the pump. The well fluid is pumped from the pump to this invention, and then pumped to the surface by this invention. The hydraulic feedback pump separates the pressure in the tubing between the wellhead and the pump into two pressure systems, reducing the liquid column pressure and load on the tubing, sucker rod, and pump below the hydraulic feedback pump. During the downstroke, the thrust of the well fluid on the bottom of the sucker rod string is reduced, which can reduce the stroke loss and clearance leakage of the pump installed below this invention, improve pump efficiency and system efficiency, reduce the breakage and uneven wear problems caused by the instability and bending of the lower sucker rod, and improve the service life of the tubing, sucker rod, and pump below this invention. This invention combines a hydraulic feedback pump with a sucker rod unloading device, overcoming the drawback of increased sucker rod load above the hydraulic feedback pump installation point in the tubing string. The installed outer tube allows leakage fluid from the unloading device to be recovered by the hydraulic feedback pump, and isolates the inside of the unloading device from the casing, eliminating the problems of production loss and unloading effect being affected by casing pressure in existing sucker rod unloading devices. Therefore, this invention offers significant economic benefits for deep well pumping. Attached Figure Description

[0008] Figure 1 This is an assembly diagram of an embodiment of the present invention. Implementation

[0009] The following is combined with Figure 1 Embodiments of the present invention will be described.

[0010] like Figure 1 As shown, an embodiment of the present invention includes an upper sucker rod connector 1, an upper oil pipe 2, an upper pump barrel 3, an upper hollow piston rod 4, a breather connector 5, a lower pump barrel 7, a lower hollow piston 8, a hydraulic feedback pump 9, a pump upper sucker rod 10, and a pump upper oil pipe 11. The outer diameter of the upper hollow piston rod 4 is smaller than the outer diameter of the lower hollow piston 8. The upper pump barrel 3 is mounted on the breather connector 5. The lower part of the upper hollow piston rod 4 is connected to the upper part of the lower hollow piston 8. The inner holes of the upper hollow piston rod 4 and the lower hollow piston 8 are drainage channels. The upper hollow piston cylinder 3 and the breather connector 5 are fitted onto the upper hollow piston rod 4. The upper hollow piston rod 4 and the upper pump cylinder 3 are sealed together. The lower hollow piston 8 is placed inside the lower pump cylinder 7. The lower hollow piston 8 and the lower pump cylinder 7 are sealed together. The breather connector 5 is installed on the upper part of the lower pump cylinder 7. The side wall of the breather connector 5 has a breather hole 5-1. The breather hole 5-1 communicates with the lower end of the upper pump cylinder 3 and the upper end of the lower pump cylinder 7. The hydraulic feedback pump 9 consists of a mover and a stator. The mover is inside the stator and can reciprocate within the stator. The lower hollow piston 8 is installed on the upper part of the lower pump cylinder 7. The lower part of the piston 8 is integrated with the upper part of the mover of the hydraulic feedback pump 9, and the lower part of the pump cylinder 7 is integrated with the upper part of the stator of the hydraulic feedback pump 9. It also includes an outer tube 6. The lower pump cylinder 7 and the hydraulic feedback pump 9 are placed inside the outer tube 6. A breathing connector 5 is connected to the upper part of the outer tube 6. The breathing hole 5-1 is inside the outer tube 6. An annular channel 6-1 is formed between the outer tube 6, the lower pump cylinder 7, and the hydraulic feedback pump 9. The upper part of the annular channel 6-1 communicates with the breathing hole 5-1. The lower part of the annular channel 6-1 is connected to the inlet of the hydraulic feedback pump 9. The upper part of the upper hollow piston rod 4 is connected to the upper sucker rod connector 1. The upper sucker rod connector 1 has a liquid outlet groove. The lower part of the mover is connected to the upper part of the upper sucker rod 10 connected to the pump pump. The lower part of the outer tube 6 is connected to the upper part of the upper oil pipe 11 connected to the pump pump. The upper outer part of the present invention is connected to the lower part of the upper oil pipe 2. The upper part of the upper oil pipe 2 is connected to the wellhead. The upper sucker rod is connected to the wellhead above the upper sucker rod connector 1.

[0011] The sucker rod unloading device is mainly composed of an upper pump cylinder 3, an upper hollow piston rod 4, a breather connector 5, a lower pump cylinder 7, and a lower hollow piston 8.

[0012] The structure of the hydraulic feedback pump 9 is as shown in Figure 2-10 on page 106 of the book "Oil Pumps" published by Petroleum Industry Press in July 1994 (it has two pump barrels with different diameters, two pistons that cooperate with the pump barrels, an inlet valve, and an outlet valve), but it is not limited to this structure. The current application of hydraulic feedback pumps is in pumping oil in heavy oil wells. In this invention, its purpose is to reduce the liquid column pressure and load borne by the tubing, sucker rod, and pump below its installation position. With technological advancements, engineers have designed various hydraulic feedback pumps, such as the rod-type heavy oil pump described in Chinese patent application 200510020054.5, which can also be used in this invention. Hydraulic feedback pumps consisting of two single-flow piston assemblies of different diameters connected in series (with an upper sucker rod joint and a lower sucker rod joint) can also be used in this invention.

[0013] The mover of the hydraulic feedback pump 9 refers to the part that moves synchronously with the sucker rod during oil extraction. It mainly includes two pistons of different diameters, an inlet valve, and a outlet valve (one of the pistons can be the lower hollow piston 8 on the sucker rod unloading device). The stator of the hydraulic feedback pump 9 refers to the stationary part mounted on the tubing, mainly consisting of two pump barrels of different diameters and other connecting parts (one of the pump barrels can be the lower pump barrel 7 on the sucker rod unloading device). In some hydraulic feedback pumps, the inlet and outlet valves are not entirely mounted on the mover; some are mounted on the mover and some on the stator. These types of outlet and inlet valves are generally mechanical valves (opening or closing according to the direction of sucker rod movement).

[0014] When the lower hollow piston 8 of the sucker rod unloading device is combined with the hydraulic feedback pump 9, the lower hollow piston 8 can be a component of the hydraulic feedback pump 9, and a component of the hydraulic feedback pump 9 can also be the lower hollow piston 8. That is, the sucker rod unloading device and the hydraulic feedback pump 9 can share the lower hollow piston 8. When the lower pump cylinder 7 of the sucker rod unloading device is combined with the hydraulic feedback pump 9, the lower pump cylinder 7 can be a component of the hydraulic feedback pump 9, and a component of the hydraulic feedback pump 9 can also be the lower pump cylinder 7. That is, the sucker rod unloading device and the hydraulic feedback pump 9 can share the lower pump cylinder 7.

[0015] In this invention, if the sucker rod unloading device and the hydraulic feedback pump 9 share the lower pump cylinder 7 and the lower hollow piston 8, the entire device consists of three pump cylinders and three pistons; if they only share the lower pump cylinder 7 and not the lower hollow piston 8, the entire device consists of three pump cylinders and four pistons; if they do not share the lower hollow piston 8 and the lower pump cylinder 7, the entire device consists of four pump cylinders and four pistons.

[0016] The "combination" in the phrase "the lower part of the hollow piston 8 and the upper part of the mover of the hydraulic feedback pump 9 are integrated" in this invention refers to two situations. In one situation, when the sucker rod unloading device and the hydraulic feedback pump 9 share the hollow piston 8, the sucker rod unloading device and the hydraulic feedback pump 9 are integrated, and this invention has three pistons. In the other situation, when the sucker rod unloading device and the hydraulic feedback pump 9 do not share the hollow piston 8, this invention has four pistons, in which case the hollow piston 8 and the upper piston of the hydraulic feedback pump 9 are connected as one unit through components.

[0017] The "integration" in the phrase "the lower part of the lower pump barrel 7 and the upper part of the stator of the hydraulic feedback pump 9 are integrated" in this invention refers to two situations. In one situation, when the sucker rod unloading device and the hydraulic feedback pump 9 share the lower pump barrel 7, the sucker rod unloading device and the hydraulic feedback pump 9 are integrated. In the other situation, when the sucker rod unloading device and the hydraulic feedback pump 9 do not share the lower pump barrel 7, and this invention has four pump barrels, the lower pump barrel 7 and the upper pump barrel of the hydraulic feedback pump 9 are connected as one unit.

[0018] This invention organically combines a sucker rod unloading device and a hydraulic feedback pump, which are installed on the tubing and sucker rod between the wellhead and the pump. The well fluid is pumped to this invention by the pump and then pumped to the surface by this invention for unloading.

[0019] The hydraulic feedback pump 9 divides the pressure in the tubing between the wellhead and the pump into two pressure systems, reducing the pressure and load on the tubing, sucker rod, and pump installed below the hydraulic feedback pump 9. During the downstroke, the thrust of the well fluid on the bottom of the sucker rod string is reduced, thereby reducing the stroke loss caused by the elastic expansion and contraction of the sucker rod and tubing under this invention, reducing leakage between the pump piston and the pump barrel, improving displacement, pump efficiency and system efficiency, reducing breakage and uneven wear problems caused by the instability and bending of the lower sucker rod, extending the service life of the tubing, sucker rod and pump under this invention, and reducing deep pumping costs.

[0020] With the installation of the outer pipe 6, the sucker rod unloading device connects the breather hole 5-1 to the inlet of the hydraulic feedback pump 9. Leakage from the gaps between the upper hollow piston rod 4 and the upper pump barrel 3, and between the lower hollow piston 8 and the lower pump barrel 7, flows back to the inlet of the hydraulic feedback pump 9 through the breather hole 5-1 and the annular channel 6-1. This avoids the displacement loss caused by leakage from the sucker rod unloading device flowing back to the casing, thus improving well discharge, pump efficiency, and system efficiency. The pressure at the inlet of the hydraulic feedback pump 9 is close to zero. The pressure on the upper end face of the connected lower hollow piston 6 is also close to zero, while the pressure on the upper end face of the upper hollow piston rod 4 and the lower end face of the lower hollow piston 6 is the fluid column pressure in the tubing above its installation position. The lower hollow piston 6 is subjected to the upward thrust of the well fluid, thereby reducing the load on the sucker rod and the pumping unit above its installation position, extending its service life, improving the efficiency of the pumping unit, and eliminating the influence of casing pressure on the load reduction effect of the sucker rod unloading pumping device. The unloading effect is good, and it has a constant unloading effect in pumping wells with high casing fluid level and casing pressure. During the casing dilution and viscosity reduction process, although the added thin oil fills the casing and increases the casing pressure, the added thin oil does not enter the annular channel 6-1 and will not affect the unloading effect of the unloading device. It can be used in conjunction with the casing dilution and viscosity reduction process for heavy oil extraction.

[0021] The upper oil pipe 2, the pump sucker rod 10, and the pump oil pipe 11 are assembled on site, while the remaining components are manufactured and assembled at the factory (if there is an oil pipe on site with an inner diameter larger than the outer diameter of the lower pump barrel 7 and the outer diameter of the hydraulic feedback pump, the outer pipe 6 can also be assembled on site).

[0022] The piston (rod) and pump barrel sealing refers to compliance with the requirements specified in GB / T 18607 standard. Pump diameter refers to the inner diameter of the oil pump barrel.

Claims

1. A reciprocating rod pump relay load reduction deep pumping device, characterized in that: The system includes an upper pump cylinder (3), an upper hollow piston rod (4), a breather connector (5), a lower pump cylinder (7), a lower hollow piston (8), and a hydraulic feedback pump (9). The outer diameter of the upper hollow piston rod (4) is smaller than that of the lower hollow piston (8). The upper pump cylinder (3) is mounted on the breather connector (5). The lower part of the upper hollow piston rod (4) is connected to the upper part of the lower hollow piston (8). The inner holes of the upper hollow piston rod (4) and the lower hollow piston (8) are drainage channels. The upper pump cylinder (3) and the breather connector (5) are fitted onto the upper hollow piston rod (4). The upper hollow piston rod (4) and the upper pump cylinder (3) are sealed together. The lower hollow piston (8) is placed inside the lower pump cylinder (7). The lower hollow piston (8) and the lower pump cylinder (7) are sealed together. The breather connector (5) is mounted on the upper part of the lower pump cylinder (7). The side wall of the breather connector (5) has a breather hole (5-1). The breather hole (5-1) The lower end of the upper pump cylinder (3) and the upper end of the lower pump cylinder (7) are connected. The hydraulic feedback pump (9) consists of a mover and a stator. The mover is inside the stator and can reciprocate inside the stator. The lower part of the lower hollow piston (8) is integrated with the upper part of the mover of the hydraulic feedback pump (9). The lower part of the lower pump cylinder (7) is integrated with the upper part of the stator of the hydraulic feedback pump (9). It also includes an outer pipe (6), a lower pump cylinder (7), and a hydraulic feedback pump ( 9) Insert into the outer tube (6), the breathing connector (5) is connected to the upper part of the outer tube (6), the breathing hole (5-1) is inside the outer tube (6), the outer tube (6) forms an annular channel (6-1) between the lower pump cylinder (7) and the hydraulic feedback pump (9), the upper part of the annular channel (6-1) is connected to the breathing hole (5-1), and the lower part of the annular channel (6-1) is connected to the inlet of the hydraulic feedback pump (9); The sucker rod unloading device includes the upper pump barrel (3), the upper hollow piston rod (4), the breather connector (5), the lower pump barrel (7), and the lower hollow piston (8).

2. The reciprocating rod pump relay load reduction deep pumping device according to claim 1, characterized in that: The lower hollow piston (8) of the sucker rod unloading device can also be set separately. When the lower hollow piston (8) is set separately, the lower hollow piston (8) and the upper piston of the hydraulic feedback pump (9) are connected as one unit through components.

3. The reciprocating rod pump relay load reduction deep pumping device according to claim 1, characterized in that: The lower pump cylinder (7) of the sucker rod unloading device can also be set separately. When the lower pump cylinder (7) is set separately, the lower pump cylinder (7) is connected to the upper pump cylinder of the hydraulic feedback pump (9) as a whole.

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