Negative pressure pump type self-priming sand bailing tube for sand bailing operation

Abstract

The invention relates to a negative pressure pump type self-priming sand bailing cylinder for sand bailing operation, comprising a sand suction nozzle, a high-pressure storage chamber, a liquid guide joint, a low-pressure storage chamber and a shear pin conducting valve; the shear pin conducting valve comprises a pressure cap valve seat and a shear shaft, one end of the shear shaft is axially provided with a first liquid guide hole, the shear shaft is radially provided with a through hole, the first liquid guide hole is conductively connected with the through hole, the shear shaft passes through a hollow position of the pressure cap valve seat and is fixed to the pressure cap valve seat by a shear pin; the liquid guide joint is axially provided with a through second liquid guide hole; a piston is arranged in the high-pressure storage chamber; two sides of the high-pressure storage chamber are respectively fixedly connected with the liquid guide joint and the sand suction nozzle, the other end of the liquid guide joint is fixedly connected with one end of the low-pressure storage chamber, the other end of the low-pressure storage chamber is fixedly connected with the pressure cap valve seat, and the first liquid guide hole and the second liquid guide hole are through-connected by a liquid guide tube with a retractable length; the invention utilizes a double-chamber structure to form negative pressure flow and realize the delayed suction function of the piston.

Description

Technical Field

[0001] The invention belongs to the technical field of gas well exploitation, and in particular relates to a negative pressure pump type self-priming sand bailing barrel used for sand bailing operations. Background Art

[0002] Sand coming out of the well is a common phenomenon. During the process of salvaging the throttle, the throttle is often buried by mud and sand. The sand bailing barrels commonly used in wireline operations are: valve-type sand bailing barrel, pump-type sand bailing barrel, and negative pressure sand bailing barrel.

[0003] Among them, the Valve-type sand bailing barrel can be used to salvage granular objects in the well. The single-flow ball seat at the bottom can prevent the mud and sand that enter the barrel from flowing out. It is suitable for bailing a small amount of sand. The mud and sand can be squeezed into the sand bailing barrel by repeatedly inserting and pulling out the barrel from the mud and sand. No sand can be salvaged when encountering hard sand surface. It is most suitable for bailing soft mud.

[0004] The pump-type sand bailing barrel uses the piston suction principle to suck granular objects in the well into the barrel. The single-flow ball seat at the bottom can prevent the objects entering the barrel from flowing out of the barrel. The piston is pulled upward by a steel wire to form a suction force to suck mud and sand into the sand bailing barrel. The prerequisite is that the sand bailing nozzle can be inserted into the mud and sand and is properly stuck by the mud and sand. Otherwise, when the piston is pulled up, the sand bailing nozzle will leave the mud and sand surface and cannot suck sand, making the operation difficult.

[0005] The negative pressure sand bailing barrel can salvage granular objects in the well, and use the negative pressure to suck the granular objects into the barrel. It is suitable for cleaning up sediment with a small amount of sediment, especially the sediment around buried objects. It mainly uses a large pressure difference to form a rapid flow to suck mud and sand into the sand bailing barrel. The upward plunger is not sealed with the inner wall of the barrel, and the pressure balance is completed instantly. There is no need to pull the steel wire upward, and it cannot be operated repeatedly. It is suitable for a small amount of sand. During the sand removal process, natural gas and preset air are easy to mix, and there is a risk of explosion during the ground sand removal process.

[0006] In view of the above problems, it is necessary to study a negative pressure pump type self-priming sand bailing barrel for sand bailing operations with a longer negative pressure balance time, a longer duration of the piston suction process, and higher safety. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a negative pressure pump type self-priming sand bailing barrel for sand bailing operations with a longer negative pressure balance time, a longer duration of a piston suction process and higher safety.

[0008] The present invention solves the technical problem by adopting the following technical solutions:

[0009] A negative pressure pump type self-priming sand bailing tube for sand bailing operation comprises a sand suction nozzle, a high pressure storage chamber, a liquid guide joint, a low pressure storage chamber and a shear pin guide valve;

[0010] The shear pin conducting valve comprises a pressure cap valve seat and a shear shaft, one end of the shear shaft is axially provided with a first liquid guide hole, the shear shaft is radially provided with a through hole, the first liquid guide hole is conductively connected with the through hole, the shear shaft passes through the hollow position of the pressure cap valve seat and is fixed to it by a shear pin; the liquid guide joint is axially provided with a through second liquid guide hole; a piston is arranged in the high-pressure storage chamber; the two sides of the high-pressure storage chamber are respectively fixedly connected with the liquid guide joint and the sand suction nozzle, the other end of the liquid guide joint is fixedly connected with one end of the low-pressure storage chamber, the other end of the low-pressure storage chamber is fixedly connected with the pressure cap valve seat, and the first liquid guide hole and the second liquid guide hole are through-connected by a liquid guide tube with a retractable length;

[0011] The self-priming sand bailing tube is pre-filled with liquid in the high-pressure storage chamber before entering the well, and the piston is located on the side close to the sand suction nozzle. When the shear pin is cut off to make the shear axis move toward the low-pressure storage chamber, the liquid in the high-pressure storage chamber enters the low-pressure storage chamber through the first liquid guide hole, and the piston moves to the liquid guide joint side, thereby sucking mud and sand into the high-pressure storage chamber.

[0012] Furthermore, the shear shaft passes through the side wall of the pressure cap valve seat located in the low-pressure storage chamber to form a step structure, which limits the shear shaft from completely escaping from the pressure cap valve seat.

[0013] Furthermore, when the shear shaft is connected to the pressure cap valve seat via the shear pin, the shear shaft and the pressure cap valve seat are in sealed contact, so that liquid cannot enter the low-pressure storage chamber through the through hole.

[0014] Furthermore, at least two sealing rings are arranged between the shear shaft and the pressure cap valve seat, so that when the shear shaft is fixed by the shear pin, the through hole is located between the sealing rings, and after the shear pin is cut off, the shear shaft moves, and the through hole moves to the outside of the two sealing rings, so that the through hole is connected to the low-pressure storage chamber.

[0015] Furthermore, an end face sealing valve is installed on the side wall of the liquid guiding joint, and the injection and outflow pressure relief of the liquid are achieved through the end face sealing valve.

[0016] Furthermore, the end face sealing valve is provided with a through water injection hole, and the side wall of the liquid guiding joint is provided with a side hole. When the end face sealing valve is loosened, the water injection hole is connected with the side hole. When the end face sealing valve is tightened and closed, the side hole is pressed by the end face sealing valve, and the water injection hole and the side hole cannot be connected.

[0017] Furthermore, a one-way valve structure is provided in the sand suction nozzle, and the one-way valve structure can prevent mud and sand from flowing out of the high-pressure storage chamber.

[0018] Furthermore, the one-way valve structure includes a steel ball and a limiting cross block rod, a conical hole is formed in the sand suction nozzle, the steel ball is located between the limiting cross block rod and the conical hole, and the limiting cross block rod is installed on the side closer to the high-pressure storage chamber than the conical hole.

[0019] Furthermore, a plurality of semicircular side teeth are provided at the bottom of the sand suction nozzle.

[0020] Furthermore, the volume of the high-pressure storage chamber is smaller than that of the low-pressure storage chamber, so that when bailing sand, all the liquid can be diverted into the low-pressure storage chamber.

[0021] The advantages and positive effects of the present invention are:

[0022] The present invention utilizes a double-chamber structure, pre-sets liquid and a piston on one side and pre-sets air on the other side, and utilizes a shear pin conducting valve to conduct the double chambers to form a negative pressure flow, thereby realizing a delayed suction function of the piston. The suction time is extended compared with the existing negative pressure sand bailing barrel, and the piston self-priming function is added compared with the existing pump-type sand bailing barrel, and there is no need to lift the piston with a steel wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0024] Figure 1 A structural cross-sectional view of a negative pressure pump type self-priming sand bailing barrel for sand bailing operations provided by an embodiment of the present invention;

[0025] Figure 2 A structural cross-sectional view of a sand suction nozzle of a negative pressure pump type self-priming sand bailing barrel for sand bailing operations provided by an embodiment of the present invention;

[0026] Figure 3 A structural cross-sectional view of a liquid guide joint of a negative pressure pump type self-priming sand bailing tube for sand bailing operations provided by an embodiment of the present invention;

[0027] Figure 4 A schematic structural diagram of a liquid guide tube of a negative pressure pump type self-priming sand bailing barrel for sand bailing operations provided by an embodiment of the present invention;

[0028] Figure 5 A structural cross-sectional view of a pressure cap valve seat of a negative pressure pump type self-priming sand bailing tube for sand bailing operations provided by an embodiment of the present invention;

[0029] Figure 6 This is a structural cross-sectional view of the shear axis of a negative pressure pump type self-priming sand bailing barrel for sand bailing operations provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] First, it should be noted that the specific structure, features and advantages of the present invention will be specifically described below by way of example, but all descriptions are only for illustration and should not be understood as limiting the present invention in any way. In addition, any single technical feature described or implied in the embodiments mentioned herein can still be combined or deleted between these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned herein.

[0031] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0032] like Figure 1-6 As shown, the present invention provides a negative pressure pump type self-priming sand bailing barrel for sand bailing operation, comprising a sand suction nozzle 1, a high pressure storage chamber 2, a liquid guide joint 3, a low pressure storage chamber 4 and a shear pin guide valve 5;

[0033] The shear pin conducting valve 5 is a conducting valve for the high-pressure storage chamber and the low-pressure storage chamber, including a cap valve seat 22 and a shear shaft 23. A first liquid guide hole 17 is axially arranged at one end of the shear shaft 23, and a through hole 28 is radially arranged on the shear shaft 23. The first liquid guide hole is connected to the through hole. The shear shaft 23 passes through the hollow position of the cap valve seat 22 and is fixed to it by a shear pin 24. The shear shaft 23 passes through the cap valve seat 24 and is located in the inner part of the low-pressure storage chamber 4. The side wall forms a step structure 27 to limit the shear shaft 23 from completely escaping from the cap valve seat 24. The shear shaft 23 and the cap valve seat 22 are fixed by the shear pin 24. 4, the shear shaft 23 is in sealed contact with the pressure cap valve seat 22, so that the liquid cannot enter the low-pressure storage chamber 4 through the through hole; specifically, at least two sealing rings 14 are arranged between the shear shaft 23 and the pressure cap valve seat 22, so that when the shear shaft 23 is fixed by the shear pin 24, the through hole is located between the sealing rings, and after the shear pin 24 is cut off, the shear shaft moves, and the through hole moves to the outside of the two sealing rings 14, so that the through hole is connected with the low-pressure storage chamber 4; the side wall of the pressure cap valve seat is provided with a through hole in the horizontal direction, and the shear pin can be inserted after the hole is aligned with the horizontal pin hole 25 of the shear shaft; the lower end of the pressure cap valve seat is a male thread 10, which is connected with the female thread at the upper end of the low-pressure storage chamber 4.

[0034] The liquid-conducting joint 3 is axially provided with a second liquid-conducting hole 29 that passes through it; an end face sealing valve 15 is installed on the side wall of the liquid-conducting joint 3, and the injection and outflow pressure relief of the liquid are realized through the end face sealing valve 15; specifically, a through water injection hole 19 is provided on the end face sealing valve 15, and a side hole 18 is provided on the side wall of the liquid-conducting joint 3. When the end face sealing valve 15 is loosened, the water injection hole is connected with the side hole, and when the end face sealing valve 15 is tightened and closed, the side hole 18 is pressed by the end face sealing valve 15, and the water injection hole and the side hole cannot be connected; in addition, there are male threads at both ends of the liquid-conducting joint 3, the lower end is connected to the high-pressure storage chamber 2, and the upper end is connected to the low-pressure storage chamber 4, and the end of the liquid-conducting joint 3 connected to the low-pressure storage chamber 4 is a conical sealing joint 16, which is connected to the liquid-conducting tube 20 nut to seal with a conical surface.

[0035] The high pressure storage chamber 2 is provided with a piston; the high pressure storage chamber 2 includes an outer tube 12 and a piston 13, and the piston 13 can move up and down in the tube; before entering the well, liquid is pre-filled in the high pressure storage chamber 2, and the piston 13 is pushed to one end of the sand suction nozzle by the liquid. There are female threads at both ends of the outer tube 12, the lower end is connected to the sand suction nozzle 1, and the upper end is connected to the liquid guide joint 3. A sealing ring can be provided on the piston to make it slide up and down in the outer tube 12 in a sealed manner.

[0036] Before entering the well, the low-pressure storage chamber 4 is preset with normal-pressure air inside, and its volume is larger than that of the high-pressure storage chamber. The lower end is connected to the liquid guide joint 3 with a female thread, and the upper end is connected to the shear pin guide valve 5 with a female thread. A liquid guide tube 20 is built in. The liquid guide tube 20 is a spring metal tube that guides clean water from the high-pressure storage chamber 2 to the low-pressure storage chamber 4. Both ends have union joints 21. The upper end is connected to the male thread at the bottom of the shear shaft 23, and the conical surface is sealed; the lower end is connected to the conical surface sealing joint 16 of the liquid guide joint 3, and the conical surface is sealed.

[0037] A one-way valve structure is provided in the sand suction nozzle 1, and the one-way valve structure can prevent mud and sand from flowing out of the high-pressure storage chamber 2; the one-way valve structure includes a steel ball 6 and a limit cross block rod 8, and a conical hole 7 is formed in the sand suction nozzle. The steel ball 6 is located between the limit cross block rod 8 and the conical hole, and the limit cross block rod 8 is installed on the side closer to the high-pressure storage chamber 2 than the conical hole. A plurality of semicircular side teeth 9 are provided at the bottom of the sand suction nozzle to facilitate sand suction.

[0038] The two sides of the high-pressure storage chamber 2 are respectively fixedly connected to the liquid guide joint 3 and the sand suction nozzle 1, the other end of the liquid guide joint 3 is fixedly connected to one end of the low-pressure storage chamber 4, the other end of the low-pressure storage chamber 4 is fixedly connected to the pressure cap valve seat 22, and the first liquid guide hole and the second liquid guide hole are connected through a liquid guide tube with a retractable length; it should be noted that when the various components are connected, the technicians can make sealing connections according to the actual situation and construction requirements, and the sealing method adopts the existing technology, such as a sealing ring, which is well known to those skilled in the art and will not be repeated here.

[0039] The self-priming sand bailing tube is pre-filled with liquid in the high-pressure storage chamber 2 before entering the well, and the piston is located on the side close to the sand suction nozzle 1. When the shear pin 24 is cut off to make the shear shaft 23 move toward the low-pressure storage chamber 4, the liquid in the high-pressure storage chamber 2 enters the low-pressure storage chamber 4 through the first liquid guide hole, and the piston moves toward the liquid guide joint 3, thereby sucking mud and sand into the high-pressure storage chamber 2.

[0040] It should be noted that the volume of the high-pressure storage chamber 2 is smaller than the volume of the low-pressure storage chamber 4, so that all the liquid can be diverted into the low-pressure storage chamber 4 when scooping sand; and the upper end of the shear shaft 23 is connected to a threaded buckle 26 connected to an appropriate variable buckle joint, which serves as a downward limiter and can be connected to other tool strings.

[0041] As an example, in this embodiment, before the self-priming sand bailing barrel of the present invention enters the well, clean water is preset in the high-pressure storage chamber 2, and normal-pressure air is preset in the low-pressure storage chamber 4. After the sand bailing barrel reaches the sand surface and encounters resistance, the wire tool string jar is operated to smash down to cut the shear pin between the pressure cap valve seat and the shear shaft. After shearing, the shear shaft moves downward, and clean water flows to the low-pressure storage chamber 4. The piston of the high-pressure storage chamber 2 moves upward to form a suction effect. When smashing down, the sand suction nozzle 1 will also be inserted into the mud and sand. The piston moves upward under the action of the downhole pressure and pushes clean water into the low-pressure storage chamber; negative pressure is formed at the lower end of the piston, the one-way valve opens, and the mud and sand are sucked into the chamber. As the mud and sand are sucked in, the weighted rod will press the sand bailing barrel to sink, so that the sand suction nozzle 1 always moves down close to the mud and sand surface, and the piston moves up to the end face of the liquid guide joint 3 to stop, the suction is completed, the one-way valve is closed, the mud and sand remain in the high-pressure storage chamber 2, and the sand bailing is completed. Compared with the existing negative pressure sand bailing barrel, the present invention prolongs the suction time, adds the piston self-priming function compared with the existing pump-type sand bailing barrel, does not need a steel wire to lift the piston, utilizes a double-chamber structure, and innovates a negative pressure delay mechanism to form a continuous suction function.

[0042] The above embodiments describe the present invention in detail, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A negative pressure pump type self-priming sand bailing tube for sand bailing operation, characterized in that: It includes a sand suction nozzle, a high-pressure storage chamber, a liquid guide joint, a low-pressure storage chamber and a shear pin guide valve; The shear pin conducting valve comprises a pressure cap valve seat and a shear shaft, one end of the shear shaft is axially provided with a first liquid guide hole, the shear shaft is radially provided with a through hole, the first liquid guide hole is conductively connected with the through hole, the shear shaft passes through the hollow position of the pressure cap valve seat and is fixed to it by a shear pin; the liquid guide joint is axially provided with a through second liquid guide hole; a piston is arranged in the high-pressure storage chamber; the two sides of the high-pressure storage chamber are respectively fixedly connected with the liquid guide joint and the sand suction nozzle, the other end of the liquid guide joint is fixedly connected with one end of the low-pressure storage chamber, the other end of the low-pressure storage chamber is fixedly connected with the pressure cap valve seat, and the first liquid guide hole and the second liquid guide hole are through-connected by a liquid guide tube with a retractable length; The self-priming sand bailing tube is pre-filled with liquid in the high-pressure storage chamber before entering the well, and the piston is located near the side of the sand suction nozzle. When the shear pin is cut off to make the shear axis move toward the low-pressure storage chamber, the liquid in the high-pressure storage chamber enters the low-pressure storage chamber through the first liquid guide hole, and the piston moves toward the liquid guide joint side, thereby sucking mud and sand into the high-pressure storage chamber; When the shear shaft is connected to the pressure cap valve seat through the shear pin, the shear shaft and the pressure cap valve seat are in sealed contact, so that the liquid cannot enter the low-pressure storage chamber through the through hole; At least two sealing rings are arranged between the shear shaft and the pressure cap valve seat, so that when the shear shaft is fixed by the shear pin, the through hole is located between the two sealing rings, and after the shear pin is cut off, the shear shaft moves, and the through hole moves to the outside of the two sealing rings, so that the through hole is connected to the low-pressure storage chamber.

2. The negative pressure pump type self-priming sand bailing barrel for sand bailing operation according to claim 1, characterized in that: The shear shaft passes through the side wall of the pressure cap valve seat located in the low-pressure storage chamber to form a step structure, which limits the shear shaft from moving upward and completely escaping from the pressure cap valve seat.

3. The negative pressure pump type self-priming sand bailing barrel for sand bailing operation according to claim 1, characterized in that: An end face sealing valve is installed on the side wall of the liquid guiding joint, and the injection and outflow pressure relief of the liquid are realized through the end face sealing valve.

4. The negative pressure pump type self-priming sand bailing barrel for sand bailing operation according to claim 3, characterized in that: The end face sealing valve is provided with a through water injection hole, and the side wall of the liquid guiding joint is provided with a side hole. When the end face sealing valve is loosened, the water injection hole is connected with the side hole. When the end face sealing valve is tightened and closed, the side hole is pressed by the end face sealing valve, and the water injection hole and the side hole cannot be connected.

5. The negative pressure pump type self-priming sand bailing barrel for sand bailing operation according to claim 1, characterized in that: A one-way valve structure is arranged inside the sand suction nozzle, and the one-way valve structure can prevent mud and sand from flowing out of the high-pressure storage chamber.

6. The negative pressure pump type self-priming sand bailing barrel for sand bailing operation according to claim 5, characterized in that: The one-way valve structure includes a steel ball and a limit cross block rod. A conical hole is formed in the sand suction nozzle. The steel ball is located between the limit cross block rod and the conical hole. The limit cross block rod is installed on the side closer to the high-pressure storage chamber than the conical hole.

7. The negative pressure pump type self-priming sand bailing barrel for sand bailing operation according to claim 1, characterized in that: A plurality of semicircular side teeth are arranged at the bottom of the sand suction nozzle.

8. The negative pressure pump type self-priming sand bailing barrel for sand bailing operation according to claim 1, characterized in that: The volume of the high-pressure storage chamber is smaller than that of the low-pressure storage chamber, so that when bailing sand, all the liquid can be diverted into the low-pressure storage chamber.

Images