An air-proof feedback oil pumping unit

Abstract

A gas feedback oil pump is disclosed, comprising a discharge valve and an inlet valve that are one-way valves. The pump diameter of the upper pump barrel is smaller than that of the lower pump barrel, and the length of the upper piston is greater than that of the upper pump barrel. A rod joint, upper piston, discharge valve, valve joint, inlet valve, and lower piston are connected sequentially. The interior of the upper piston communicates with the outside through a discharge channel provided on the rod joint or the upper piston. The upper piston passes through the upper pump barrel and the pump barrel joint. The lower pump barrel is fitted over the lower piston. The upper pump barrel, pump barrel joint, and lower pump barrel are connected sequentially. A pump chamber is formed between the outer wall of the upper piston and the inner wall of the lower pump barrel due to their diameter difference. A connecting groove is provided on the valve joint. A gas transfer groove is provided on the upper piston, the length of which is less than the length of the upper pump barrel. Gas accumulated in the upper part of the pump chamber can be transferred to the pump when the upper piston moves upward, eliminating the influence of gas on the operation of the feedback oil pump (where the upper pump diameter is smaller than the lower pump diameter), improving oil well production, and resulting in significant economic benefits.

Description

Technical Field

[0001] This invention pertains to oil pumps used in oilfields, and is a gas feedback-proof oil pump. Background Technology

[0002] The oil pump shown in Figure 2-10 on page 106 of the book "Oil Pumps" published by Petroleum Industry Press in July 1994 is a type of hydraulic feedback oil pump. It consists of two pump barrels of different diameters, two matching plungers, and other accessories. When the sucker rod descends, the area difference between the two plungers and the pressure difference between the inlet and outlet oil generate a downward force, called the feedback force. Therefore, this type of oil pump is called a feedback oil pump. The generated downward feedback force helps the sucker rod move downwards, which is beneficial for working in heavy oil; therefore, it is sometimes also called a heavy oil pump. Based on the principle of the feedback oil pump disclosed in Figure 2-10 on page 106 of the book "Oil Pumps" published by Petroleum Industry Press in July 1994, those skilled in the art have designed various feedback oil pumps for use with special oil pumps. One type of feedback oil pump has a smaller upper pump barrel and a larger lower pump barrel. In this type of feedback pump, the fluid is discharged from the bottom of the pump chamber, while the gas accumulates in the upper part of the pump chamber due to the density difference. Therefore, the gas is difficult to expel when pumping oil, which can lead to problems such as gas affecting pump efficiency and gas lock, resulting in low oil well production or even no oil production, and causing significant economic losses. Summary of the Invention

[0003] The present invention aims to provide a gas-proof feedback oil pump to solve the problems of reduced pump efficiency and gas lock caused by gas accumulation in the upper part of the pump chamber in existing feedback oil pumps with an upper pump diameter smaller than the lower pump diameter in oil wells with high gas content, thereby improving the economic benefits of oil wells.

[0004] The objective of this invention is achieved as follows: It includes a rod connector, an upper pump barrel, an upper piston, a pump barrel connector, a discharge valve, a valve joint, an inlet valve, a lower pump barrel, and a lower piston. The discharge valve and inlet valve are one-way valves, allowing well fluid to flow upwards only, not downwards. The diameter of the upper pump barrel is smaller than that of the lower pump barrel, and the length of the upper piston is greater than that of the upper pump barrel. The rod connector, upper piston, discharge valve, valve joint, inlet valve, and lower piston are connected sequentially. The interior of the upper piston communicates with the outside through a discharge channel provided on the rod connector or the upper piston. The upper piston passes through the upper pump barrel... The pump barrel joint consists of a lower pump barrel fitted over a lower piston, and an upper pump barrel, pump barrel joint, and lower pump barrel connected in sequence. The upper piston and the upper pump barrel are sealed together, and the lower piston and the lower pump barrel are sealed together. A pump chamber is formed between the outer wall of the upper piston and the inner wall of the lower pump barrel due to the difference in their diameters. The valve joint has a connecting groove, which allows well fluid to enter the pump chamber after passing through the inlet valve during the downstroke. During the upstroke, the well fluid can be discharged from the pump chamber and discharged to the rod joint through the discharge valve. A gas transfer groove is provided on the upper piston, and the length of the gas transfer groove is less than the length of the upper pump barrel.

[0005] The beneficial effects of this invention are: a gas transfer groove is provided on the upper piston, so that the gas accumulated in the upper part of the pump chamber can be transferred to the pump through the gas transfer groove when the upper piston moves upward. This solves the problem of reduced pump efficiency and gas lock caused by gas accumulation in the upper part of the pump chamber of feedback pumping pumps with an upper pump diameter smaller than the lower pump diameter. It also eliminates the influence of gas on the operation of the above-mentioned type of feedback pumping pump, which can improve oil well production and has significant economic benefits. Attached Figure Description

[0006] Figure 1 This is a structural diagram of the present invention. Detailed Implementation

[0007] The following is in conjunction with the appendix Figure 1 Embodiments of the present invention will be described.

[0008] Depend on Figure 1As can be seen, the embodiments of the present invention include a rod joint 1, an upper pump barrel 2, an upper piston 3, a pump barrel joint 4, a drain valve 5, a valve joint 6, an inlet valve 7, a lower pump barrel 8, and a lower piston 9. The drain valve 5 and the inlet valve 7 are one-way valves, and the well fluid can only flow upward through the drain valve 5 and the inlet valve 7, and cannot flow downward. The pump diameter of the upper pump barrel 2 is smaller than the pump diameter of the lower pump barrel 8, and the length of the upper piston 3 is greater than the length of the upper pump barrel 2. The rod joint 1, the upper piston 3, the drain valve 5, the valve joint 6, the inlet valve 7, and the lower piston 9 are connected in sequence. The interior of the upper piston 3 communicates with the outside through a discharge channel 3-1 provided on the rod joint 1 or the upper piston 3 (the discharge channel 3-1 can be provided on the rod joint 1 or the upper piston 9). The upper piston 3 passes through the upper pump cylinder 2 and the pump cylinder connector 4. The lower pump cylinder 8 is fitted over the lower piston 9. The upper pump cylinder 2, the pump cylinder connector 4, and the lower pump cylinder 8 are connected in sequence. The upper piston 3 and the upper pump cylinder 2 cooperate to seal, and the lower piston 9 and the lower pump cylinder 8 cooperate to seal. The outer wall of the upper piston 3 and the inner wall of the lower pump cylinder 8 form a pump chamber 8-1 due to the difference in their diameters. There is a connecting groove 6-1 on the valve joint 6, so that the well fluid can enter the pump chamber 8-1 after passing through the inlet valve 7 during the downstroke. During the upstroke, the well fluid can be discharged from the pump chamber 8-1 and discharged to the rod joint 1 through the discharge valve 5. A gas transfer groove 3-2 is provided on the upper piston 3. The length of the gas transfer groove 3-2 is less than the length of the upper pump cylinder 2.

[0009] The number of gas transfer grooves 3-2 provided on the upper piston 3 is one to several. When the upper piston 3 is at the lower starting point, the lower end of the first gas transfer groove 3-2 counted from top to bottom is below the lower end of the upper pump cylinder 2. The distance between the lower end of the previous gas transfer groove 3-2 and the upper end of the next gas transfer groove 3-2 is less than the length of the upper pump cylinder 2.

[0010] The principle of gas prevention in this invention is as follows: due to the density difference between gas and liquid, the gas is located in the upper part of the pump chamber 8-1. When the upper piston 3 moves upward, the gas transfer groove 3-2 will be located in the upper part of the pump chamber 8-1. The gas is transferred to the upper pump cylinder 2 through the gas transfer groove 3-2, thereby eliminating the influence of gas on the operation of the oil pump.

[0011] The connection point between the upper pump tubing and the present invention is determined based on the well depth and the size of the upper pump barrel 2. If the pump is lowered too deep, or the diameter of the upper pump barrel 2 is too small and its strength is insufficient for the well lowering requirements, a connecting pipe is installed at the upper end of the pump barrel connector 4. The connecting pipe is located outside the upper pump barrel 2, and its upper part is connected to the upper pump tubing. If the pump is lowered too shallow, or the diameter of the upper pump barrel 2 is too large and its strength is sufficient for the well lowering requirements, the upper pump tubing can be directly connected to the upper part of the upper pump barrel 2.

[0012] The upper pump cylinder 2, upper piston 3, lower pump cylinder 8, lower piston 9, drain valve 5, and inlet valve 7 are standard components.

[0013] The present invention can also add an inlet valve to the lower end of the lower pump barrel 8 to form an oil pump with anti-gas and variable displacement.

[0014] The present invention can also be modified by adding components to form a rod-type anti-gas feedback oil pump or a rod-type anti-gas variable displacement oil pump.

Claims

1. A gas feedback-proof oil pump, comprising a rod joint (1), an upper pump barrel (2), an upper piston (3), a pump barrel joint (4), a drain valve (5), a valve joint (6), an inlet valve (7), a lower pump barrel (8), and a lower piston (9). The drain valve (5) and the inlet valve (7) are one-way valves, and the well fluid can only flow upward through the drain valve (5) and the inlet valve (7), and cannot flow downward through the inlet valve. The pump diameter of the upper pump barrel (2) is smaller than the pump diameter of the lower pump barrel (8), and the length of the upper piston (3) is greater than the length of the upper pump barrel (2). The rod joint (1), the upper piston (3), the drain valve (5), the valve joint (6), the inlet valve (7), and the lower piston (9) are connected in sequence. The upper piston (3) is internally connected to the rod joint (1) or the upper piston (3). The discharge channel is connected to the outside. The upper piston (3) passes through the upper pump cylinder (2) and the pump cylinder connector (4). The lower pump cylinder (8) is fitted outside the lower piston (9). The upper pump cylinder (2), the pump cylinder connector (4), and the lower pump cylinder (8) are connected in sequence. The upper piston (3) and the upper pump cylinder (2) are sealed together. The lower piston (9) and the lower pump cylinder (8) are sealed together. The outer wall of the upper piston (3) and the inner wall of the lower pump cylinder (8) form a pump chamber (8-1) due to the difference in their diameters. There is a connecting groove (6-1) on the valve joint (6) so that the well fluid can enter the pump chamber (8-1) after passing through the inlet valve (7) during the downstroke. During the upstroke, the well fluid can be discharged from the pump chamber (8-1) and discharged to the rod joint (1) through the discharge valve (5). Its characteristics are: A gas transfer groove (3-2) is provided on the upper piston (3), the length of which is less than the length of the upper pump cylinder (2).

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