A reciprocating rod pump segmented oil extraction device

Abstract

A reciprocating rod pump segmented oil extraction device includes an upper tubing, a sucker rod, and a pump. A hydraulic feedback pump is installed between the pump and the wellhead. The external portion of the hydraulic feedback pump divides the upper tubing into two sections. The external portion of the hydraulic feedback pump is installed on the upper part of the lower section of the upper tubing and the lower part of the upper section of the upper tubing. The internal portion of the hydraulic feedback pump divides the sucker rod into two sections. The lower end of the internal portion of the hydraulic feedback pump is connected to the upper end of the lower section of the sucker rod, and the upper end of the internal portion of the hydraulic feedback pump is connected to the lower end of the upper section of the sucker rod. When the sucker rod drives the hydraulic feedback pump and the pump to reciprocate up and down, the crude oil in the well is pressurized by the pump to the hydraulic feedback pump, and then pressurized by the hydraulic feedback pump to the wellhead. It can reduce the liquid column pressure and liquid column load on the lower tubing, lower sucker rod, and sucker pump, reduce leakage in the sucker pump clearance, reduce stroke loss, avoid pressure fluctuations in the lower tubing during the up and down strokes, and extend the service life of the sucker pump, lower sucker rod, and tubing.

Description

Technical Field

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

[0002] A reciprocating rod pump oil extraction system used in oil fields includes 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 sucker rod, which in turn drives the pump in a reciprocating motion to pump crude oil from the well to the surface. With this type of reciprocating rod pump oil extraction system, the larger the pump diameter and the greater the pump depth, the greater the liquid column pressure and load borne by the sucker rod, pump, and tubing. This also leads to greater stroke loss due to the elastic expansion and contraction of the sucker rod and tubing, greater leakage between the pump piston and the pump barrel, and a shorter service life for the sucker rod, pump, and tubing, especially in deep and ultra-deep wells.

[0003] In oilfield applications, a check valve-equipped auxiliary piston, such as the one-way valve structure installed on the sucker rod between the wellhead and the pump, as described in Chinese patent application 2007101158436 "Anti-Wearing Sucker Rod String," closes its check valve during the upstroke. This reduces the liquid column load on the sucker rod below the piston, thus minimizing stroke loss and improving pump efficiency, while also extending the lifespan of the sucker rod below the piston. The reduced liquid column pressure on the tubing below the piston further reduces leakage between the pump piston and the pump barrel, improving pump efficiency. During the downstroke, the check valve opens, increasing the liquid column pressure in the tubing below the piston compared to the upstroke. This results in significant pressure fluctuations in the tubing below the piston during both the upstroke and downstroke, leading to a deterioration in stress conditions. Furthermore, the hydraulic pressure on the lower end of the sucker rod does not decrease, and the stress conditions on the lower part of the sucker rod remain poor.

[0004] Oilfield-use unloading pumping devices, such as the Chinese patent 2012202957131 "Sucker Rod Unloading Device," are installed on the tubing and sucker rod between the wellhead and the pumping unit. These devices include an upper pump barrel, an upper plunger, a lower pump barrel, a lower plunger, and a balance hole. They are used to reduce the load on the sucker rod and the pumping unit, increasing the pumping depth or displacement. If a check valve is installed on the plunger of this unloading pumping device, it combines the unloading effect of the unloading device with the pumping assistance effect of the assist piston. However, this can also lead to significant pressure fluctuations in the tubing below the unloading pumping device during the upstroke and downstroke.

[0005] The heavy oil pump and electrically heated heavy oil pump described in SY / T 7083-2016 "Special Reciprocating Oil Pumps" are hydraulic feedback pumps familiar to those skilled in the art. Apart from being used to pump heavy oil in heavy oil wells, those skilled in the art have not found any other uses for them. Summary of the Invention

[0006] The purpose of this invention is to design a reciprocating rod pump segmented oil extraction device to reduce the liquid column pressure and liquid column load borne by the lower tubing, lower sucker rod, and oil pump, reduce leakage between the pump piston and the pump barrel, reduce stroke loss caused by the elastic expansion and contraction of the lower sucker rod and lower tubing, avoid pressure fluctuations in the lower tubing during the upstroke and downstroke, and extend the service life of the oil pump, lower sucker rod, and lower tubing.

[0007] The objective of this invention is achieved as follows: It includes an upper tubing, a sucker rod, and a pump, the sucker pump being a reciprocating rod pump installed below the upper tubing and sucker rod. It also includes a hydraulic feedback pump. The external portion of the hydraulic feedback pump divides the upper tubing into two sections, and the external portion of the hydraulic feedback pump is installed above the lower section of the upper tubing and below the upper section of the upper tubing. The internal portion of the hydraulic feedback pump divides the sucker rod into two sections. The lower end of the internal portion of the hydraulic feedback pump is connected to the upper end of the lower section of the sucker rod, and the upper end of the internal portion of the hydraulic feedback pump is connected to the lower end of the upper section of the sucker rod. When the sucker rod drives the internal mechanism of the hydraulic feedback pump and the pump to reciprocate up and down, the downhole crude oil is pressurized by the pump to the hydraulic feedback pump, and then pressurized by the hydraulic feedback pump to the wellhead.

[0008] The beneficial effects of this invention are as follows: A hydraulic feedback pump is installed between the pumping unit and the wellhead. The sucker rod simultaneously drives both the hydraulic feedback pump and the pumping unit to reciprocate up and down, pumping oil. The crude oil downhole is pressurized by the pumping unit to the hydraulic feedback pump, and then further pressurized by the hydraulic feedback pump to the surface, achieving segmented oil pumping. During the up and down strokes, the two check valves of the hydraulic feedback pump open and close alternately, so that the hydraulic column pressure and load on the tubing, sucker rod, and pumping unit below the hydraulic feedback pump are no longer affected by the hydraulic column above the pumping unit. This reduces the hydraulic column pressure and load on the lower tubing, lower sucker rod, and pumping unit, reduces leakage between the pumping unit piston and the pump barrel, reduces stroke loss caused by the elastic expansion and contraction of the lower sucker rod and lower tubing, avoids pressure fluctuations in the lower tubing during the up and down strokes, and extends the service life of the pumping unit, lower sucker rod, and tubing. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the tubular column of the present invention. Detailed Implementation

[0010] The following is in conjunction with the appendix Figure 1 Embodiments of the present invention will be described.

[0011] like Figure 1 As shown, the embodiments of the present invention include a casing 1, a pump-mounted oil pipe 2, a sucker rod 3, a sucker pump 10, and a hydraulic feedback pump 11. Figure 1(The part within the double-dotted line box) The oil pump 10 is a reciprocating rod pump. The oil pump 10 has a pump barrel, an inlet valve, an outlet valve, and a plunger. The plunger of the oil pump 10 is sealed with its pump barrel. The pump barrel of the oil pump 10 is installed at the lower part of the upper tubing 2 and the sucker rod 3. The upper end of the upper tubing 2 is suspended on the wellhead device. A hydraulic feedback pump 11 is installed between the oil pump 10 and the wellhead. The upper tubing 2, the hydraulic feedback pump 11, and the oil pump 10 are all located inside the casing 1. The exterior of the hydraulic feedback pump 11 (mainly composed of two pump barrels of different diameters connected together) divides the upper tubing 2 into two sections. The exterior of the hydraulic feedback pump 11 is installed on the lower section of the upper tubing 2. The upper part of the pump is connected to the lower part of the upper section of the pump tubing 2 (the lower part of the hydraulic feedback pump 11 is connected to the upper part of the lower section of the pump tubing 2, and the lower part of the upper section of the pump tubing 2 is connected to the upper part of the hydraulic feedback pump 11). The interior of the hydraulic feedback pump 11 divides the sucker rod 3 into two sections. The lower end of the interior of the hydraulic feedback pump 11 is connected to the upper end of the lower section of the sucker rod 3, and the upper end of the interior of the hydraulic feedback pump 11 is connected to the lower end of the upper section of the sucker rod 3. When the sucker rod 3 drives the internal mechanism of the hydraulic feedback pump 11 and the pump 10 to move up and down, the well fluid is pressurized by the pump 10 to the hydraulic feedback pump 11, and then pressurized by the hydraulic feedback pump 11 to the wellhead, which is segmented pumping.

[0012] The oil pump 10 can be an existing downhole reciprocating rod pump or various special oil pumps. For some special pumps, the lower end of the sucker rod 3 and its connection point are different. Regardless of where the lower end of the sucker rod 3 is connected to the special pump, it is within the protection scope of this invention.

[0013] The hydraulic feedback pump 11 has various names in the field, such as feedback pump, hydraulic feedback heavy oil pump, and heavy oil pump. The most common name is feedback pump, which is the terminology commonly used by those skilled in the art. The most common structure of the hydraulic feedback pump 11 is shown in Figure 2-10 on page 106 of the book "Oil Pumps" published by Petroleum Industry Press in July 1994. It includes an upper pump barrel 4, an upper plunger 5, an upper check valve 6, a lower pump barrel 7, a lower plunger 8, and a lower check valve 9. The upper plunger 5, upper check valve 6, lower plunger 8, and lower check valve 9 are connected (e.g., ...). Figure 1As shown, the upper plunger 5 is located inside the upper pump barrel 4, and the upper plunger 5 and the upper pump barrel 4 are sealed together (designed according to the standard of oil pumps). The lower plunger 8 is located inside the lower pump barrel 7, and the lower plunger 8 and the lower pump barrel 7 are sealed together (designed according to the standard of oil pumps). The well fluid can only flow upward through the lower check valve 9 and the upper check valve 6, and cannot flow downward through the upper check valve 6 and the lower check valve 9. The pump diameter of the upper pump barrel 4 is larger than the pump diameter of the lower pump barrel 7, forming a pump chamber 4-1. When the sucker rod 3 moves upward, the volume of the pump chamber 4-1 increases, the upper check valve 6 closes, the internal pressure decreases, the lower check valve 9 opens, and the well fluid pumped by the oil pump 10 enters the pump chamber 4-1. When the sucker rod 3 moves downward, the volume of the pump chamber 4-1 decreases, the lower check valve 9 closes, the internal pressure increases, the upper check valve 6 opens, and the well fluid that has entered the pump chamber 4-1 is discharged into the upper section of the pump tubing 2. During the up and down strokes, one of the upper check valve 6 and the lower check valve 9 of the hydraulic feedback pump 11 is always kept closed. This ensures that the pressure and load on the upper oil pipe 2, sucker rod 3, and pump 10 below the hydraulic feedback pump 11 are no longer affected by the liquid column above the hydraulic feedback pump 11. This reduces the pressure and load on the upper oil pipe 2, sucker rod 3, and pump 10 below the hydraulic feedback pump 11, reduces leakage between the piston and the pump barrel of the pump 10, reduces stroke loss caused by the elastic expansion and contraction of the oil pipe 2 and sucker rod 2 below the hydraulic feedback pump 11, avoids pressure fluctuations in the upper oil pipe 2 below the hydraulic feedback pump 11 during the up and down strokes, and extends the service life of the pump 11 and the sucker rod 3 and lower oil pipe 2 below the hydraulic feedback pump 11.

[0014] Hydraulic feedback pumps, also a type of reciprocating rod pump, utilize the area difference and pressure difference between the upper and lower plungers to generate a downward thrust (this force is called the feedback force, hence the term "feedback pump" used by engineers). This thrust helps the sucker rod string descend, overcoming the friction between the sucker rod string and the heavy oil during its descent, synchronizing the downward movement of the sucker rod with the downstroke of the pumping unit, and ensuring the normal operation of the pumping system. Therefore, this type of pump is often called a heavy oil pump and is currently only used for pumping heavy oil wells. With technological advancements, engineers have designed various hydraulic feedback pumps, all derived from the technology shown in Figure 2-10 on page 106 of the book "Pumps" published by Petroleum Industry Press in July 1994 (the principle of the feedback force is the same). For example, Chinese patent application 2005100200545, "Rod-type Heavy Oil Pump," is one type of feedback pump and can also be used in this invention. Some of the feedback pumps developed based on the above can be used in this invention. Any feedback pump that connects its lower end to the upper end of the lower section of the sucker rod 3, allowing well fluid to enter from the lower end of the lower pump barrel (containing two pump barrels of different diameters, two plungers that mate with the pump barrels, an inlet valve, and an outlet valve) can be used in this invention to achieve its objective. Therefore, the structure of the hydraulic feedback pump 11 in this invention is not limited to the structure described herein. Feedback pumps with other structures that achieve the objectives of this invention are all within the scope of protection of this invention.

Claims

1. A reciprocating rod pump segmented oil extraction device, comprising an upper oil pipe (2), a sucker rod (3), and an oil pump (10), wherein the oil pump (10) is a reciprocating rod pump, and the oil pump (10) is installed at the lower part of the upper oil pipe (2) and the sucker rod (3), characterized in that, It also includes a hydraulic feedback pump (11), which is installed between the oil pump (10) and the wellhead. The outside of the hydraulic feedback pump (11) divides the upper tubing (2) into two sections. The lower part of the hydraulic feedback pump (11) is connected to the upper end of the lower section of the upper tubing (2), and the lower end of the upper section of the upper tubing (2) is connected to the upper part of the hydraulic feedback pump (11). The inside of the hydraulic feedback pump (11) divides the sucker rod (3) into two sections. Divided into two sections, the lower end of the hydraulic feedback pump (11) is connected to the upper end of the lower section of the sucker rod (3), and the upper end of the hydraulic feedback pump (11) is connected to the lower end of the upper section of the sucker rod (3). When the sucker rod (3) drives the internal mechanism of the hydraulic feedback pump (11) and the pump (10) to move up and down, the crude oil in the well is pressurized by the pump (10) to the hydraulic feedback pump (11), and then pressurized by the hydraulic feedback pump (11) to the wellhead. The hydraulic feedback pump (11) includes an upper pump barrel (4), an upper plunger (5), an upper check valve (6), a lower pump barrel (7), a lower plunger (8), and a lower check valve (9). The upper plunger (5), the upper check valve (6), the lower plunger (8), and the lower check valve (9) are connected. The upper plunger (5) is located inside the upper pump barrel (4) and is sealed to the upper pump barrel (4). The lower plunger (8) is located inside the lower pump barrel (7) and is sealed to the lower pump barrel (7). The well fluid can only flow upward through the lower check valve (9) and the upper check valve (6) and cannot flow downward through the upper check valve (6) and the lower check valve (9).

Images