An inclined well sand prevention oil pump

Abstract

A kind of inclined well sand prevention oil pump, including a plunger assembly and a pump barrel assembly, the pump barrel including a bridge pipe, a middle coupling and a two-way joint, a pump barrel extension tube is arranged inside the pump barrel assembly, a sand settling annulus is formed between the pump barrel extension tube and the bridge pipe, a short pump barrel is arranged at the upper end of the pump barrel extension tube, and the short pump barrel and the long plunger are slidably sealed; an oil inlet valve cover is arranged inside the middle coupling, and the oil inlet valve cover and the two-way joint form a sand falling annulus, a stopper is arranged above the oil inlet valve cover, and the outer circumference of the stopper is It has a conical structure; when the sand in the pump cavity is deposited downward, it can slide along the outer conical surface of the block to the sand falling ring space outside the oil inlet valve cover. When the sand in the upper oil pipe of the oil pump falls on the upper oil outlet valve cover, it will slide along the upper conical surface of the upper oil outlet valve cover to the annular sand settling space on both sides, and will not directly fall into the upper oil outlet valve cover or the matching surface between the pump barrel and the long plunger, thereby reducing the sand entering the pump to cause sand jam, or depositing on the valve cover to cause sand burial.

Description

Technical Field

[0001] The invention relates to the field of oil well pumps, in particular to an inclined well sand prevention oil well pump. Background Art

[0002] At present, many domestic oilfields have oil wells with high deviated angles and horizontal wells, and they contain a lot of sand. When using inclined well pumps for production, sand often enters the pump, causing sand jams and sand burials. Even after sand prevention tools such as sand filter screens are hung at the bottom of the pump, there are still a lot of sand entering the pump, resulting in reduced pump efficiency and a shortened pump inspection cycle. Although the use of sand-proof pumps can solve problems such as sand jams and sand burials, they cannot be adapted to inclined wells, and the ball valve often does not sit properly, closes late, and leaks sideways, resulting in low pump efficiency or even no oil. Therefore, it is necessary to use an inclined well sand-proof pump with a more reasonable structure that can adapt to the production of crude oil in inclined and vertical wells and horizontal wells and has a good sand-proof effect. However, the existing inclined well sand-proof pumps still have many shortcomings, mainly manifested in:

[0003] (1) Conventional inclined well sand prevention oil pumps are usually improved on the basis of ordinary inclined well oil pumps by improving the details of the component structure on the plunger assembly, such as using equal-diameter plungers or adding sand scraper rings, etc. The sand prevention effect is limited, especially when the pumping is stopped, it cannot prevent sand burial.

[0004] (2) With the development of drilling technology, there are more and more cluster wells, directional wells and horizontal wells, and the inclination of oil wells is increasing. The inclination angle of some wells even exceeds 60°. Conventional inclined well sand control pumps can only adapt to well inclination angles below 60°. When the well inclination exceeds 60°, the valve ball is increasingly affected by gravity, and the valve ball may still fail to sit on the valve seat in the center, resulting in problems such as delayed closing of the ball valve and side leakage. Summary of the invention

[0005] The main purpose of the present invention is to provide an inclined well sand prevention oil pump to solve the problem that when oil pumping in an inclined well cannot prevent sand burial and the well inclination angle exceeds 60°, the valve ball is increasingly affected by gravity and the valve ball still cannot sit on the valve seat in the center, resulting in delayed closing of the ball valve and side leakage.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: an inclined well sand prevention oil pump, including a plunger assembly and a pump barrel assembly, the pump barrel assembly includes a bridge pipe, an intermediate coupling and a two-way joint, a pump barrel extension cylinder is arranged inside the pump barrel assembly, a sand settling annulus is formed between the pump barrel extension cylinder and the bridge pipe, a short pump barrel is arranged at the upper end of the pump barrel extension cylinder, and the short pump barrel and the long plunger are slidably sealed;

[0007] An oil inlet valve cover is arranged inside the middle coupling, and the oil inlet valve cover and the two-way joint form a sand falling annulus. A stopper is arranged above the oil inlet valve cover, and the outer circumference of the stopper is a conical structure;

[0008] When the sand in the pump cavity is deposited downward, it can slide along the outer conical surface of the stopper and fall into the sand falling annular space outside the oil inlet valve cover.

[0009] In a preferred embodiment, a plurality of guide ribs are provided inside the oil inlet valve cover, and the oil inlet valve ball is slidably arranged inside the oil inlet valve cover via the guide ribs.

[0010] In the preferred embodiment, a blind hole is provided inside the stopper, a stop pin is provided inside the blind hole, one end of the stop pin is connected to the stopper via a third spring (18), and the other end of the stopper abuts against the end surface of the oil inlet valve ball.

[0011] In a preferred embodiment, the outer diameter of the stopper is larger than the diameter of the oil outlet of the oil inlet valve cover.

[0012] In the preferred embodiment, the lower end of the pump barrel extension tube is threadedly connected to the middle coupling, and the short pump barrel at the upper end of the pump barrel extension tube is connected to the bridge pipe through a support ring.

[0013] In a preferred embodiment, a sand settling tail pipe is provided below the two-way joint, the sand settling tail pipe is connected with the sand falling annulus through the axial flow hole of the two-way joint, and a plug is provided at the end of the sand settling tail pipe.

[0014] In the preferred embodiment, the upper oil outlet valve ball in the long plunger is provided with an upper oil outlet valve cover, and a first spring is provided inside the upper oil outlet valve cover, one end of the first spring abuts against the upper oil outlet valve cover, and the other end abuts against the upper oil outlet valve ball.

[0015] In the preferred embodiment, the lower oil outlet valve ball in the long plunger is provided with a lower oil outlet valve cover, and a second spring is provided inside the lower oil outlet valve cover, one end of the second spring abuts against the lower oil outlet valve cover, and the other end abuts against the lower oil outlet valve ball.

[0016] In a preferred embodiment, a plurality of guide rib structures are provided inside the upper oil outlet valve cover and the lower oil outlet valve cover, and the lower oil outlet valve ball and the upper oil outlet valve ball are provided to slide inside the guide ribs.

[0017] In a preferred embodiment, the two-way joint is provided with a plurality of oil inlet holes.

[0018] The present invention provides an inclined well sand prevention oil pump, which has an innovative sand prevention structure design adapted to the inclined well, has a simple and reliable structure, and has a wide range of applications. It can adapt to the production of crude oil in inclined vertical wells and horizontal wells, and has a good sand prevention effect. The present invention has the following advantages:

[0019] It breaks through the structural limitations of ordinary inclined well sand control pumps, and has sand control structure design for the upper and lower parts of the pump, and has a larger sand settling space. It is very suitable for inclined vertical wells and horizontal wells with high sand content. Compared with existing ordinary inclined well sand control pumps, it has a simpler structure, better reliability and longer service life.

[0020] The upper part of the pump adopts a bridge pipe design, which not only protects the pump barrel, but also can withstand the external force load of downhole tools such as sand settling tail pipe or packer, avoiding the pump barrel from bending and deformation due to axial or radial force in the inclined well section, and preventing the pump from getting stuck.

[0021] Since the short pump barrel and the pump barrel extension barrel are fixed on the middle hoop through threaded connection, it is a cantilever structure design. The short pump barrel is supported by the support ring in the circumferential direction, and there is a small gap between the support ring and the inner hole of the bridge pipe. Therefore, the short pump barrel is in a slightly floating state, so that there is no tension between the pump barrel and the plunger, resulting in rigid eccentric wear, causing pump leakage and reduced pump efficiency.

[0022] The outer diameter of the upper oil outlet valve cover is larger than the diameter of the long plunger, and its liquid outlet is lateral. When sand in the upper oil pipe of the oil pump falls onto the valve cover, it will slide along the upper conical surface of the valve cover to the annular sand settling space on both sides, and will not fall directly into the valve cover or the matching surface between the pump barrel and the plunger, reducing the sand entering the pump to cause sand jam, or depositing on the valve cover to cause sand burial.

[0023] An anti-sand oil inlet valve ball with a sand settling tail pipe is adopted. A block with a conical surface is designed on the upper part of the oil inlet valve cover. The maximum outer diameter of the block is larger than the diameter of the valve cover oil outlet, which has a shielding effect on the valve cover oil outlet. When the sand-containing crude oil enters the pump cavity through the oil inlet valve ball, the sand deposited in the pump cavity will not fall directly into the oil inlet valve cover, but will fall on the conical surface of the block. Under the action of gravity, it will slide along the conical surface to the annular space on both sides, and then fall into the sand settling tail pipe through the axial hole of the two-way joint, thereby preventing sand from being deposited in the oil inlet valve cover and interfering with the normal operation of the oil inlet valve ball.

[0024] Guide ribs are designed in the oil inlet valve cover and the oil outlet valve cover to limit the radial runout of the valve ball and keep it aligned with the valve seat during axial runout. A reset spring is designed in the oil outlet valve cover, and a stop pin acted upon by the spring force is designed on the upper part of the oil inlet valve ball. The spring or the stop pin always fits against the surface of the valve ball, and the preload force of the spring is greater than the weight of the valve ball, so that the valve ball can be reset at any well inclination angle. When the ball valve is closed, the valve ball can be seated on the valve seat in time under the action of the spring force, reducing the phenomenon of the valve ball falling off, delayed closing, or even not closing due to the influence of gravity in highly inclined wells or horizontal wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0026] Figure 1 It is the overall structure diagram of the present invention;

[0027] Figure 2 This is a partial enlarged structural diagram of the guide rib of the present invention;

[0028] Figure 3 The present invention Figure 1 A is an enlarged structural diagram;

[0029] In the figure: upper coupling 1; supporting ring 2; short pump barrel 3; bridge pipe 4; pump barrel extension tube 5; middle coupling 6; two-way joint 7; sand settling tail pipe 8; plug 9; upper oil outlet valve cover 10; first spring, upper oil outlet valve ball 12; long plunger 13; lower oil outlet valve cover 14; second spring; lower oil outlet valve ball 16; block 17; third spring; stop pin 19; oil inlet valve ball 20; oil inlet valve cover 21; oil inlet hole 22; sand falling annulus 23; guide rib 24; flow hole 25. DETAILED DESCRIPTION

[0030] Example 1

[0031] like Figures 1 to 3 As shown, a sand prevention oil pump for inclined wells includes a plunger assembly and a pump barrel assembly. The pump barrel assembly includes a bridge pipe 4, a middle coupling 6 and a two-way joint 7. A pump barrel extension 5 is provided inside the pump barrel assembly. A sand settling annulus is formed between the pump barrel extension 5 and the bridge pipe 4. A short pump barrel 3 is provided at the upper end of the pump barrel extension 5. The short pump barrel 3 is slidably and sealingly connected to the long plunger 13. With this structure, as Figure 1 As shown, when sand in the upper oil pipe of the oil pump falls onto the upper oil outlet valve cover 10, it will slide along the upper conical surface of the upper oil outlet valve cover 10 to the annular sand settling space on both sides, and will not directly fall into the upper oil outlet valve cover 10 or the matching surface between the pump barrel and the long plunger 13, thereby reducing the sand from entering the pump to cause sand jam, or depositing on the valve cover to cause sand burial.

[0032] An oil inlet valve cover 21 is provided inside the middle coupling 6, and the oil inlet valve cover 21 and the two-way joint 7 form a sand falling annulus 23. A block 17 is provided above the oil inlet valve cover 21, and the outer circumference of the block 17 is a conical structure. When the sand particles in the pump cavity are deposited downward, they can slide along the outer conical surface of the block 17 to the sand falling annulus 23 outside the oil inlet valve cover 21. According to this structure, a stopper 17 with a conical surface is designed on the upper part of the oil inlet valve cover 21. The maximum outer diameter of the stopper 17 is larger than the diameter of the oil outlet of the oil inlet valve cover 21, which has a shielding effect on the oil outlet of the oil inlet valve cover 21. When the sand-containing crude oil enters the pump chamber through the oil inlet valve cover 21, the sand particles deposited in the pump chamber will not directly fall into the oil inlet valve cover 21, but fall on the conical surface of the stopper, and slide along the conical surface under the action of gravity to the sand falling annulus 23 on both sides, and then fall into the sand settling tail pipe 8 through the axial hole of the two-way joint 7, thereby preventing the sand particles from being deposited in the oil inlet valve cover 21 and interfering with the normal operation of the oil inlet valve ball.

[0033] In the preferred embodiment, the oil inlet valve cover 21 is provided with a plurality of guide ribs 24, and the oil inlet valve ball 20 is slidably arranged inside the oil inlet valve cover 21 through the guide ribs 24. With this structure, guide ribs are designed inside both the oil inlet valve cover 21 and the oil outlet valve cover, which can limit the radial runout of the valve ball, so that the valve ball always remains in a state of being aligned with the valve seat during axial runout.

[0034] In the preferred embodiment, a blind hole is provided inside the stopper 17, and a stopper pin 19 is provided inside the blind hole. One end of the stopper pin 19 is connected to the stopper 17 through a third spring 18, and the other end of the stopper 17 abuts against the end face of the oil inlet valve ball 20. With this structure, combined with the description in the previous part, a third spring 18 is designed inside the oil inlet valve cover 21, and a stopper pin 19 under the elastic force of the spring is designed on the upper part of the oil inlet valve cover 21. The spring or the stopper pin 19 always fits the surface of the valve ball, and the preload force of the third spring 18 is greater than the weight of the valve ball, so that the valve ball can be reset at any well inclination angle. When the ball valve is closed, the valve ball can be seated on the valve seat in time under the action of the spring force, which reduces the phenomenon that the valve ball is affected by gravity in a highly inclined well or horizontal well, and falls, closes lagging, or even does not close.

[0035] In the preferred embodiment, the outer diameter of the stopper 17 is larger than the oil outlet diameter of the oil inlet valve cover 21. With this structure, the upper part of the oil inlet valve cover 21 is designed with a stopper 17 with a conical surface, and the maximum outer diameter of the stopper 17 is larger than the oil outlet diameter of the oil inlet valve cover 21, which has a shielding effect on the oil outlet of the oil inlet valve cover 21.

[0036] In the preferred embodiment, the lower end of the pump barrel extension 5 is threadedly connected to the middle coupling 6, and the short pump barrel 3 at the upper end of the pump barrel extension 5 is connected to the bridge pipe 4 through the support ring 2. With this structure, since the short pump barrel 3 and the pump barrel extension 5 are fixed on the middle coupling 6 through threaded connection, it is a cantilever structure design, and the short pump barrel 3 is supported by the support ring 2 in the circumferential direction, and there is a small gap between the support ring 2 and the inner hole of the bridge pipe 4, so the short pump barrel 3 is in a slightly floating state, so that there will be no tension between the pump barrel and the plunger, forming rigid eccentric wear, causing pump leakage and reduced pump efficiency.

[0037] In the preferred embodiment, a sand settling tail pipe 8 is provided below the two-way joint 7, the sand settling tail pipe 8 is connected to the two-way joint 7 through a flow hole 25, and a plug 9 is provided at the end of the sand settling tail pipe 8. With this structure, under the action of gravity, the sand slides down the conical surface into the sand falling annulus 23 on both sides, and then falls into the sand settling tail pipe 8 through the axial flow hole 25 of the two-way joint 7, preventing the sand from being deposited in the oil inlet valve cover 21 and interfering with the normal operation of the oil inlet valve ball.

[0038] In the preferred embodiment, an upper oil outlet valve cover 10 is provided above the upper oil outlet valve ball 12 in the long plunger 13, and a first spring 11 is provided inside the upper oil outlet valve cover 10, one end of the first spring 11 abuts against the upper oil outlet valve cover 10, and the other end abuts against the upper oil outlet valve ball 12. With this structure, the first spring 11 is designed on the upper part of the upper oil outlet valve cover 10, the first spring 11 always fits with the surface of the valve ball, and the preload force of the first spring 11 is greater than the weight of the valve ball, so that the valve ball can be reset at any well inclination angle. When the ball valve is closed, the valve ball can be seated on the valve seat in time under the action of the spring force, which reduces the phenomenon that the valve ball is affected by gravity in a highly deviated well or horizontal well, and thus deviates, closes lagging, or even does not close.

[0039] In the preferred embodiment, a lower oil outlet valve cover 14 is provided above the lower oil outlet valve ball 16 in the long plunger 13, and a second spring 15 is provided inside the lower oil outlet valve cover 14, one end of the second spring 15 abuts against the lower oil outlet valve cover 14, and the other end abuts against the lower oil outlet valve ball 16. With this structure, the second spring 15 is designed on the upper part of the lower oil outlet valve cover 14, the second spring 15 always fits with the surface of the valve ball, and the preload force of the second spring 15 is greater than the weight of the valve ball, so that the valve ball can be reset at any well inclination angle. When the ball valve is closed, the valve ball can be seated on the valve seat in time under the action of the spring force, which reduces the phenomenon that the valve ball is affected by gravity in a highly deviated well or horizontal well, and thus deviates, closes lagging, or even does not close.

[0040] In the preferred embodiment, the upper oil outlet valve cover 10 and the lower oil outlet valve cover 14 are provided with guide rib structures, and the lower oil outlet valve ball 16 and the upper oil outlet valve ball 12 are provided to slide inside the guide ribs. With this structure, the structure and the guide ribs designed inside the oil inlet valve cover 21 and the oil outlet valve cover described above can limit the radial runout of the valve ball, so that it always maintains the same state of centering with the valve seat during axial runout. The phenomenon of the valve ball falling off, closing delay, or even not closing due to the influence of gravity in a highly deviated well or horizontal well is reduced.

[0041] In the preferred embodiment, the two-way joint 7 is provided with a plurality of oil inlet holes 22. According to this structure, the oil inlet holes 22 are used for oil inlet.

[0042] Example 2

[0043] Further illustrate with reference to Example 1, Figures 1 to 3 As shown, the pump barrel assembly consists of an upper coupling 1, a supporting ring 2, a short pump barrel 3, a bridge pipe 4, a pump barrel extension tube 5, a middle coupling 6, a two-way joint 7, a sand settling tail pipe 8, a plug 9, a block 17, a third spring 18, a stop pin 19, an oil inlet valve ball 20, and an oil inlet valve cover 21.

[0044] The plunger assembly is composed of an upper oil outlet valve cover 10, a first spring 11, an upper oil outlet valve ball 12, a long plunger 13, a lower oil outlet valve cover 14, a second spring 15, and a lower oil outlet valve ball 16.

[0045] When going down into the well, first connect the upper coupling 1 on the upper end of the pump barrel assembly to the oil pipe, and lower it into the designed position in the oil well together with the oil pipe string. Then connect the upper end of the plunger assembly to the sucker rod, and lower it to the bottom of the oil pipe together with the sucker rod string to achieve pump collision with the pump barrel assembly.

[0046] During pumping operations, the plunger assembly, driven by the sucker rod, reciprocates up and down in the pump barrel assembly.

[0047] During the upward stroke, the plunger assembly moves upward, the upper and lower oil outlet valve balls are closed 12, 16, the volume of the pump chamber at the lower part of the plunger assembly increases, the pressure drops, the oil inlet valve ball 20 opens under the action of the sinking pressure, and the crude oil enters the pump chamber through the oil inlet port 22 on the side of the two-way joint 7. At this time, the sand particles entering the pump chamber together with the crude oil are deposited in the annular space of the sand falling annulus 23 outside the sand prevention oil inlet valve ball due to gravity, and finally fall into the sand settling tail pipe 8 through the axial flow hole of the two-way joint 7.

[0048] During the downstroke, the plunger assembly moves downward, the volume of the pump chamber below the plunger assembly decreases, the pressure increases, and the oil inlet valve ball 20 is closed under the oil pressure in the pump chamber. At the same time, the upper and lower oil outlet valve balls 12 and 16 are opened under the oil pressure in the pump chamber, the oil pipe chamber is connected to the pump chamber, and the crude oil in the pump chamber is squeezed out and enters the oil pipe on the upper part of the plunger assembly. At this time, the sand particles entering the oil pipe through the plunger assembly fall into the sand settling annulus due to gravity.

[0049] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A sand prevention oil pump for inclined wells, characterized by: The pump barrel assembly comprises a plunger assembly and a pump barrel assembly, wherein the pump barrel assembly comprises a bridge pipe (4), an intermediate coupling (6) and a two-way joint (7), a pump barrel extension tube (5) is provided inside the pump barrel assembly, a sand settling annulus is formed between the pump barrel extension tube (5) and the bridge pipe (4), a short pump barrel (3) is provided at the upper end of the pump barrel extension tube (5), and the short pump barrel (3) and the long plunger (13) are slidably sealed; An oil inlet valve cover (21) is provided inside the middle coupling (6), the oil inlet valve cover (21) and the two-way joint (7) form a sand falling annulus (23), a stopper (17) is provided above the oil inlet valve cover (21), and the outer circumference of the stopper (17) is in a conical structure; When the sand in the pump cavity is deposited downward, it can slide along the outer conical surface of the stopper (17) and fall into the sand falling annulus (23) outside the oil inlet valve cover (21); The oil inlet valve cover (21) is provided with a plurality of guide ribs (24) inside, and the oil inlet valve ball (20) is slidably arranged inside the oil inlet valve cover (21) via the guide ribs (24); A blind hole is provided inside the stopper (17), a stopper pin (19) is provided inside the blind hole, one end of the stopper pin (19) is connected to the stopper (17) via a third spring (18), and the other end of the stopper (17) abuts against the end surface of the oil inlet valve ball (20); The outer diameter of the stopper (17) is larger than the diameter of the oil outlet of the oil inlet valve cover (21); The lower end of the pump barrel extension tube (5) is threadedly connected to the middle coupling (6), and the short pump barrel (3) at the upper end of the pump barrel extension tube (5) is connected to the bridge pipe (4) via a support ring (2).

2. According to claim 1, a sand prevention oil pump for inclined wells is characterized by: A sand settling tail pipe (8) is provided below the two-way joint (7); the sand settling tail pipe (8) is in communication with the two-way joint (7) via a flow hole (25); and a plug (9) is provided at the end of the sand settling tail pipe (8).

3. The inclined well sand prevention oil pump according to claim 1, characterized in that: An upper oil outlet valve cover (10) is provided above the upper oil outlet valve ball (12) in the long plunger (13), and a first spring (11) is provided inside the upper oil outlet valve cover (10). One end of the first spring (11) abuts against the upper oil outlet valve cover (10), and the other end abuts against the upper oil outlet valve ball (12).

4. The inclined well sand prevention oil pump according to claim 3 is characterized by: A lower oil outlet valve cover (14) is provided above the lower oil outlet valve ball (16) in the long plunger (13), and a second spring (15) is provided inside the lower oil outlet valve cover (14). One end of the second spring (15) abuts against the lower oil outlet valve cover (14), and the other end abuts against the lower oil outlet valve ball (16).

5. The inclined well sand prevention oil pump according to claim 4, characterized in that: A plurality of guide rib structures are provided inside the upper oil outlet valve cover (10) and the lower oil outlet valve cover (14), and the lower oil outlet valve ball (16) and the upper oil outlet valve ball (12) are provided inside the guide ribs to slide.

6. The inclined well sand prevention oil pump according to claim 1, characterized in that: The two-way joint (7) is provided with a plurality of oil inlet holes (22).

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