Double cylinder multi-plunger deep well liquid lifting device

Abstract

A double-cylinder multi-plunger deep well liquid lifting device, which is used together with a windable light rod or a sucker rod, so that the stroke of the liquid lifting device can reach more than 60 meters. It includes a barrel column assembly and a multi-plunger assembly, wherein the barrel column assembly includes a lower double-walled cylinder, an upper double-walled cylinder, and an intermediate oil pipe located between the lower double-walled cylinder and the upper double-walled cylinder, and the lower double-walled cylinder and the intermediate oil pipe, and the intermediate oil pipe and the upper double-walled cylinder are respectively connected by oil pipe couplings; the multi-plunger assembly includes multi-stage plungers of the same size arranged from top to bottom, wherein the upper end of the top first-stage plunger is provided with an internal thread matching the sucker rod, the lower end of the first-stage plunger and the upper and lower ends of the remaining plungers are completely the same in structure and are respectively provided with a radially rotatable movable valve seat and an axially swingable rotary joint; the plunger connecting rod is connected between two adjacent plungers by using the rotary joint thereon, and the lower double-walled cylinder, the intermediate oil pipe and the upper double-walled cylinder and the plungers of each stage are of the same length.

Description

Technical Field

[0001] The invention relates to oil production equipment, in particular to a double-cylinder multi-plunger deep well liquid lifting device. Background Art

[0002] The longest pump barrel used in traditional domestic oil production plants is more than 9 meters, and the maximum length in foreign countries is no more than 13 meters. In addition, due to the structural limitations of the rod pumping unit, the stroke of the rod pumping unit is generally 6-8 meters. Due to the stroke limitation, the rod pumping unit is not suitable for deep wells, low permeability wells, heavy oil wells and gas wells.

[0003] At present, various types of windable bare rods or sucker rods have been put into use in China. The matching long-stroke oil pumps connect multiple pump barrels together. This structure requires very high manufacturing precision of the pump barrel, and on-site assembly is also very troublesome, making it difficult to promote and popularize. Summary of the invention

[0004] The present invention aims to solve the above-mentioned problems existing in the above-mentioned prior art and provides a double-cylinder multi-plunger deep well liquid lifting device. The device is used together with a windable bare rod or a sucker rod, so that the stroke of the liquid lifting device can reach more than 60 meters, breaking the limitation that the longest stroke of the existing rod-type sucker rod pump is only 9 meters, and overcoming the defect that the stroke of the rod-type sucker rod pump is limited and is not suitable for low-yield oil wells, deep wells, and heavy oil wells.

[0005] The technical solution of the present invention is: a double-cylinder multi-plunger deep well liquid lifting device, which is special in that it includes a barrel string assembly and a multi-plunger assembly located in the lower oil pipe and the barrel string assembly, the barrel string assembly includes a lower double-wall cylinder, an upper double-wall cylinder and an intermediate oil pipe located between the lower double-wall cylinder and the upper double-wall cylinder, and the lower double-wall cylinder and the intermediate oil pipe, and the intermediate oil pipe and the upper double-wall cylinder are connected respectively by oil pipe couplings;

[0006] The multi-plunger assembly includes multi-stage plungers of the same size arranged from top to bottom, wherein the upper end of the top first-stage plunger is provided with an internal thread matching the sucker rod, the lower end of the first-stage plunger and the upper and lower ends of the remaining plungers are completely identical in structure and are respectively provided with a radially rotatable movable valve seat and an axially swingable rotary joint; the plunger connecting rod is connected between two adjacent plungers by using the rotary joint thereon to realize radial and axial floating of the plunger connecting rod, the lower double-wall cylinder, the middle oil pipe and the upper double-wall cylinder and the plungers of each stage are of the same length, when the top surface of the first-stage plunger is located at the lower port of the upper double-wall cylinder during the oil pumping upward stroke, the top surface of the second-stage plunger adjacent to the first-stage plunger is located at the upper port of the lower double-wall cylinder, and the top surface of the third-stage plunger adjacent to the second-stage plunger is located at the lower port of the double-wall lower cylinder.

[0007] The surface of the movable valve seat is provided with an annular groove, and a plurality of through holes are evenly distributed in the circumferential direction of the plunger surface and a rotating pin is installed. The rotating pin is inserted into the annular groove to realize radial rotation of the movable valve seat and withstand axial tension.

[0008] The connection points of the movable valve seat and the rotary joint are respectively provided with radial pin holes corresponding to each other, and pin shafts are inserted into the radial pin holes, and the movable valve seat and the rotary joint are connected together through the radial pin shafts.

[0009] The plunger connecting rod is connected to the corresponding plunger through threads.

[0010] The beneficial effects of the present invention are: the lower plunger can be increased or decreased according to the specific conditions of the oil well, thereby changing the length of the stroke and achieving a long stroke. The stroke length can reach more than 60 meters, which can meet the liquid lifting requirements of deep wells and ultra-deep wells. When the stroke is increased, only two plungers work in the upper and lower cylinders, and there is no need to increase the power of the pumping unit. In order to allow the plungers of each level to enter the cylinder smoothly, the plungers of each level are connected by axial and radial floating plunger connecting rods. Compared with multi-cylinder long strokes and multi-cylinder multi-plungers, it has a simple structure, low manufacturing cost, low resistance, shortened wear-resistant section stroke, increased plunger service life, low leakage rate, high pump efficiency, and is suitable for deep wells, low permeability wells, heavy oil wells and gas wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the structure of the bobbin column assembly of the present invention;

[0012] Figure 2 is a schematic diagram of the exploded structure of the multi-plunger assembly of the present invention;

[0013] Figure 3 It is a schematic diagram of the on-site installation structure of the present invention;

[0014] Figure 4 It is a schematic diagram of the instantaneous position of the first-stage plunger of the oil pumping upward stroke entering the upper double-wall cylinder barrel of the present invention;

[0015] Figure 5 It is a schematic diagram of the instantaneous position of the second-stage plunger of the oil pumping upward stroke entering the upper double-wall cylinder barrel of the present invention.

[0016] In the figure: 1. sucker rod, 2. upper double-wall cylinder, 3. lower double-wall cylinder, 4. pin stabilizing nail, 5. valve ball, 6. valve ball cover, 7. valve ball seat, A1. lower oil pipe, A2. middle oil pipe, A3. upper oil pipe, B. oil pipe coupling, C. plunger connecting rod, D. movable valve ball, E1. first-stage plunger, E2. first-stage plunger, E3. first-stage plunger, E4. first-stage plunger, E5. first-stage plunger, E6. first-stage plunger, F. movable rotating valve seat, G. rotating pin, H. pin, K. rotating joint. DETAILED DESCRIPTION

[0017] The invention relates to a double-cylinder multi-plunger deep well liquid lifting device, comprising a barrel column assembly and a multi-plunger assembly located in the barrel column assembly.

[0018] like Figure 1 As shown, the tubing string assembly includes a lower double-wall cylinder 3, an upper double-wall cylinder 2 and an intermediate oil pipe A2 located between the lower double-wall cylinder 3 and the upper double-wall cylinder 2. The lower double-wall cylinder 3 and the intermediate oil pipe A2, as well as the intermediate oil pipe A2 and the upper double-wall cylinder 2 are connected via an oil pipe coupling B, respectively. The double-wall cylinder can prevent the cylinder from deforming during high pressure in deep wells. Figure 1 L1 in the middle is the connection mark of the section of the bobbin column assembly.

[0019] like Figure 2 As shown, Figure 2 Z1 and Z2 are the cross-sectional marks of the multi-plunger assembly. The multi-plunger assembly includes multi-stage plungers of the same size arranged from top to bottom. This embodiment takes 6 stages as an example, and from top to bottom they are the first-stage plunger E1 to the sixth-stage plunger E6. The upper end of the first-stage plunger E1 is provided with an internal thread matching the sucker rod. The lower end of the first-stage plunger E1 and the upper and lower ends of the second-stage plungers E2 to the sixth-stage plungers E6 are completely identical in structure and are respectively provided with a radially rotatable movable valve seat F and an axially swingable rotary joint K. The surface of the movable valve seat F is provided with an annular groove F1, and the surface of the plunger is provided with a circular groove F2. Multiple through holes are evenly distributed and a rotating pin G is installed. The rotating pin G is inserted into the annular groove F1 to realize radial rotation of the movable valve seat F and bear axial tension; the connection between the movable valve seat F and the rotating joint K is respectively provided with radial pin holes corresponding to each other, and the pin shaft H is inserted into the radial pin hole, and the two are connected together by the pin shaft H; the two adjacent plungers are connected to the plunger connecting rod C by threading through the rotating joint K on them, and the radial and axial floating of the plunger connecting rod C is realized under the action of the rotating pin G and the pin shaft H. The lower double-wall cylinder 3, the intermediate oil pipe A2 and the upper double-wall cylinder 2 and the plungers of each level are of the same length. When the top surface of the first-stage plunger E1 is located at the lower port of the upper double-wall cylinder 2 during the oil pumping upward stroke, the top surface of the second-stage plunger E2 is located at the upper port of the lower double-wall lower cylinder 3, and the top surface of the third-stage plunger E3 is located at the lower port of the double-wall lower cylinder 3.

[0020] During on-site installation, Figure 3As shown, the lower oil pipe assembly is lowered into the oil well, and the lower oil pipe assembly includes a valve assembly arranged from bottom to top, five lower oil pipes A1 connected in series, and the valve assembly includes a fixed valve ball cover 6, the inner cavity of the fixed valve ball cover 6 is equipped with a fixed valve ball 5, and the fixed valve ball seat 7 is threadedly connected to the fixed valve ball cover 6; then the barrel column assembly is lowered and connected to the upper oil pipe A3, and the upper oil pipe A3, the lower oil pipe A1 and the middle oil pipe A2 have the same specifications and sizes. The multi-plunger assembly is lowered step by step into the upper oil pipe A3, the barrel column assembly in the well and the lower oil pipe assembly; finally, the upper end of the first-stage plunger E1 is threadedly connected to the wellhead sucker rod. Figure 3 L2 in the middle is the cross-section mark of the lower oil pipe assembly.

[0021] When the pumping unit is pumping oil upward, Figure 4 As shown, the first-stage plunger E1 first enters the lower port of the upper double-walled cylinder 2, while the second-stage plunger E2 goes out from the upper port of the lower double-walled cylinder 3, and the third-stage plunger E3 enters the lower port of the lower double-walled cylinder 3, driving the liquid surface to lift upward; Figure 5 As shown, when the first-stage plunger E1 goes out from the upper port of the upper double-walled cylinder 2, the second-stage plunger E2 enters the lower port of the upper double-walled cylinder 2, and the third-stage plunger E3 goes out from the upper port of the lower double-walled cylinder 3, continuing to lift the liquid level upward; and so on, the lower-stage plungers enter and exit the corresponding cylinders in this order. During the reciprocating stroke of the oil pump, there is always a corresponding plunger movement in the cylinder, which greatly increases the suction stroke and lifting efficiency.

[0022] The above are only specific embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A double-cylinder multi-plunger deep well liquid lifting device, comprising a tubular column assembly and a multi-plunger assembly, characterized in that: The multi-plunger assembly is located in the lower oil pipe and barrel column assembly, and the barrel column assembly includes a lower double-wall cylinder, an upper double-wall cylinder, and an intermediate oil pipe located between the lower double-wall cylinder and the upper double-wall cylinder, and the lower double-wall cylinder and the intermediate oil pipe, and the intermediate oil pipe and the upper double-wall cylinder are respectively connected by oil pipe couplings; The multi-plunger assembly comprises a multi-stage plunger of the same size arranged from top to bottom, wherein the upper end of the top first-stage plunger is provided with an internal thread matching the sucker rod, the lower end of the first-stage plunger and the upper and lower ends of the remaining plungers are completely identical in structure and are respectively provided with a radially rotatable movable valve seat and an axially swingable rotary joint; the plunger connecting rod is connected between two adjacent plungers by means of the rotary joint thereon to achieve radial and axial floating of the plunger connecting rod; the lower double-wall cylinder, the intermediate oil pipe and the upper double-wall cylinder and the plungers of each stage are of the same length, when the top surface of the first-stage plunger is located at the lower port of the upper double-wall cylinder during the upward stroke of pumping oil, the top surface of the second-stage plunger adjacent to the first-stage plunger is located at the upper port of the lower double-wall cylinder, and the top surface of the third-stage plunger adjacent to the second-stage plunger is located at the lower port of the double-wall lower cylinder; The surface of the movable valve seat is provided with an annular groove, and a plurality of through holes are evenly distributed in the circumferential direction of the plunger surface and a rotating pin is installed. The rotating pin is inserted into the annular groove to realize radial rotation of the movable valve seat and bear axial tension; The connection points of the movable valve seat and the rotary joint are respectively provided with radial pin holes corresponding to each other, and pin shafts are inserted into the radial pin holes, and the movable valve seat and the rotary joint are connected together through the radial pin shafts.

2. The double-cylinder multi-plunger deep well liquid lifting device according to claim 1 is characterized in that: The plunger connecting rod The corresponding plungers are connected via threads.

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