CN202531405U - CBM concentric tube pump - Google Patents

Abstract

A coal bed gas concentric tube type pump is applied to the technical field of coal bed gas exploitation. The lower end of the upper joint of the outer cylinder is connected with the outer cylinder through threads; the lower end of the outer cylinder is connected with the lower joint of the outer cylinder. The upper end of the inner wall of the upper joint of the outer cylinder is provided with an annular step; the lower end of the upper joint of the pump cylinder is connected with the pump cylinder. The lower end of the pump cylinder is connected with a lower joint of the pump cylinder; the lower end surface of the upper joint of the pump barrel is arranged on an annular step on the inner wall of the upper joint of the outer barrel; the outer wall of the upper joint of the pump cylinder is provided with an axial groove. The outer wall of the lower joint of the pump cylinder is provided with an axial groove. A double traveling valve assembly is arranged in the pump cylinder. The upper part of the plunger top cover is connected with a connecting rod; the bottom end of the pump cylinder is provided with a fixed valve assembly. The effect is as follows: the coal powder is filled into the drainage channel of the coal bed gas drainage well, and the coal powder is discharged into the drainage channel through the drainage channel.

Description

CBM concentric tube pump

technical field

The utility model relates to the technical field of coal bed gas mining, in particular to a coal bed gas concentric tube pump in the process of coal bed gas mining.

Background technique

In the development of coalbed methane, the liquid drainage well plays a key role in the process of drainage and pressure reduction for gas recovery. Drainage equipment commonly used in drainage wells mainly include: tube pumps, screw pumps and electric submersible pumps. Tube pumps are the most commonly used in these liquid drainage and gas recovery methods. During the process of draining gas from the coal seam, coal powder also enters the pump barrel and the oil pipe along with the water in the coal seam. When the carrying force of the water in the oil pipe is less than the gravity of the coal powder with larger particles, the coal powder will deposit in the pump barrel and the oil pipe.

Chinese Patent Publication No.: CN201884254U discloses a special tubular pump for low-submergence coalbed methane drainage. The tubular pump includes a working pump barrel, and a working plunger, a valve seat, an oil outlet valve and an oil outlet valve cover arranged in the working pump barrel, and the pressurized stirring device is used to increase the inlet of the oil outlet valve. pressure and can stir the liquid at the bottom of the tube pump. By adding a pressurizing stirring device, the pressure at the inlet of the oil outlet valve is increased, which indirectly improves the submergence of the tube pump, which is beneficial to improve the opening ability of the oil outlet valve and increase the filling coefficient of the tube pump.

However, in the prior art, after the pulverized coal is deposited in the pump cylinder or the oil pipe, the deposition of the pulverized coal cannot be removed by well flushing. Because the coal seam has been produced by drainage and gas production for a long time, the pressure drop funnel has been formed. Even if the method of well flushing is adopted, all the well flushing water will be lost into the coal seam, and the coal powder that blocks the pump barrel or oil pipe cannot be flushed. When the pulverized coal in the pump barrel or the oil pipe is deposited to a certain amount, the entire drainage channel will be blocked, and the water in the coal seam will not be able to be discharged, forcing the production of the drainage and gas recovery of the drainage well to stagnate, and have to Perform pump inspection. Checking the pump and re-running the new pump to the well for drainage and gas production again, the entire operation period is long, which seriously affects the production of coalbed methane. And due to the damage caused to the coal seam during operation and construction, it will take a long time to recover to the original output after the well is put into production.

For coalbed methane drainage wells, due to the clogging of pump barrels or oil pipes caused by pulverized coal, frequent pump inspection operations have to be performed, which seriously affects the production and operation of coalbed methane, resulting in an increase in the cost of coalbed methane mining.

Utility model content

The purpose of this utility model is: to provide a coalbed methane concentric tube pump, which can remove the coal powder blocked in the pump barrel or the drainage channel of the oil pipe; Blocking the pump barrel or the drainage channel of the oil pipe requires frequent pump inspection operations, which affects the increase in coalbed methane production and causes the problem of increased cost of coalbed methane mining.

The technical scheme adopted by the utility model is: the coalbed methane concentric tube pump, which includes two parts: an outer cylinder assembly and an inner pump assembly. Its characteristics are:

The outer cylinder assembly is mainly composed of the upper joint of the outer cylinder, the outer cylinder and the lower joint of the outer cylinder. The upper end of the upper joint of the outer cylinder has internal threads, which can be connected to the tubing string; the lower end of the upper joint of the outer cylinder has internal threads, and the lower end of the upper joint of the outer cylinder is threaded to connect with the outer cylinder; the lower end of the outer cylinder has external threads, and the lower end of the outer cylinder is connected to the outer cylinder. Connect the lower connector. There is an annular step at the upper end of the inner wall of the joint on the outer cylinder;

The inner pump assembly is mainly composed of the upper joint of the pump barrel, the connecting rod, the pump barrel, the double swimming valve assembly, the fixed valve assembly and the lower joint of the pump cylinder. The upper end of the upper joint of the pump barrel has internal threads, which can be connected to the lower end of the inner oil pipe of the concentric oil pipe; the lower end of the upper joint of the pump barrel has external threads, and the lower end of the upper joint of the pump barrel is connected to the pump barrel. The lower end of the pump barrel has external threads, and the lower end of the pump barrel is connected to the lower joint of the pump barrel; the cross section of the upper joint of the pump barrel is circular, and the lower end surface of the upper joint of the pump barrel is on the annular step of the inner wall of the upper joint of the outer cylinder; An axial groove is arranged on the outer wall of the joint, and the axial groove connects the upper and lower ends of the joint on the pump cylinder. The cross-section of the lower joint of the pump barrel is circular. The lower joint of the pump barrel is inside the outer cylinder and connected to the lower end of the pump barrel. There are axial grooves on the outer wall of the lower joint of the pump barrel. end connection. Inside the pump cylinder, there is a double-moving valve assembly, which is composed of a plunger, a floating valve, a floating valve seat, and a floating valve baffle. The plunger is cylindrical, and the outer wall of the plunger is slidingly matched with the inner wall of the pump barrel. There are two floating valve seats fixed in the plunger, and each floating valve seat has a floating valve (steel ball) In the plunger and above the swimming valve at the lower end, there is a floating ball baffle, and a connecting rod is connected to the upper part of the plunger top cover, and there is a slanted hole on the plunger top cover; There is a fixed valve assembly at the bottom. The fixed valve assembly includes a fixed valve baffle, a fixed valve and a fixed valve seat. The fixed valve seat is fixed on the bottom of the pump barrel, a fixed valve (steel ball) is arranged on the fixed valve seat, and a fixed valve baffle plate is fixed on the fixed valve inside the pump barrel.

Briefly describe the working process of the coalbed methane concentric tube pump. See Figure 1. Connect the outer cylinder assembly in sequence as follows, outer cylinder upper joint 1, outer cylinder 4, outer cylinder lower joint 14; connect the inner pump assembly in sequence as follows, pump cylinder upper joint 2, pump cylinder 5, fixed After the Er assembly and the lower joint 13 of the pump barrel, the inner pump assembly is packed into the outer cylinder assembly.

Connect the coalbed methane concentric tube pump with other coalbed methane liquid drainage well flushing device tools sequentially on the ground, and lower them into the well. After reaching the predetermined position, the lower end of the sucker rod is connected with the connecting rod 3, and the plunger 6 is lowered into the pump cylinder 5 of the concentric tubular pump. After installing the pumping unit, drainage and gas recovery can be carried out. When it is necessary to wash the well, connect the liquid supply pump truck to the casing gate of the gas production wellhead, start the pump truck, pump clean water into the wellbore, and the wellwashing water goes down the wellbore through the diversion wellwasher, seal regulator, concentric The oil pipe reaches the annular space of the outer cylinder assembly and the inner pump assembly of the concentric tubular pump of the present invention. The pulverized coal accumulated in the inner cavity of the pump assembly and oil pipe in the pump will carry the pulverized coal to the ground.

Beneficial effects of the utility model: The coalbed methane concentric tubular pump of the utility model has an annular well-flushing channel. When the pulverized coal blocks the drainage channel of the coalbed methane drainage well, the well-flushing water can pass through this channel, which will block the drainage channel. The pulverized coal is washed to the ground. It is not necessary to check the pump to remove the pulverized coal that blocks the pump barrel or oil pipe. Well washing water will not enter the coal seam and will not cause damage to the coal seam. After the well flushing is completed, the production can be resumed directly, and the output of coalbed methane can be quickly restored to the output before the pulverized coal blocked the pump barrel or oil pipe. It has the advantages of reasonable and compact structure, convenient installation and convenient operation.

Description of drawings

Figure 1 is a schematic cross-sectional view of the structure of the utility model coalbed methane concentric tube pump.

Fig. 2 is a schematic cross-sectional view of B-B in Fig. 1, showing the positions of four axial grooves.

In the figure, 1-upper joint of outer cylinder, 2-upper joint of pump cylinder, 3-connecting rod, 4-outer cylinder, 5-pump cylinder, 6-plunger, 7-moving valve, 8-moving valve Seat, 9-moving Valve baffle, 10-fixed Valve baffle, 11-fixed Valve, 12-fixed Valve seat, 13-pump barrel lower joint, 14-outer cylinder lower joint.

Detailed ways

Embodiment 1: Taking a coalbed methane concentric tube pump as an example, the utility model is further described in detail.

See Figure 1. The utility model coalbed methane concentric tube pump includes two parts: an outer cylinder assembly and an inner pump assembly.

The urceolus assembly is mainly composed of the upper joint 1 of the urceolus, the urceolus 4 and the lower joint 14 of the urceolus. The inner diameter of the outer cylinder 4 is 85mm, and the length is 8.5m. The upper end of the upper joint 1 of the outer cylinder has an internal thread, which can be connected to the tubing string; the lower end of the upper joint 1 of the outer cylinder has an internal thread, and the lower end of the upper joint 1 of the outer cylinder is threaded to connect with the outer cylinder 4; the lower end of the outer cylinder 4 has an external thread, and the outer The lower end of the cylinder 4 is connected with the lower joint 14 of the outer cylinder. There is an annular step at the upper end of the inner wall of the joint 1 on the outer cylinder; the inner diameter of the annular step is 94mm.

The inner pump assembly is mainly composed of the upper joint 2 of the pump barrel, the connecting rod 3, the pump barrel 5, the double swimming valve assembly, the fixed valve assembly and the lower joint 13 of the pump cylinder. The inner diameter of the pump barrel 5 is 32mm, and the length is 8m. The upper end of the upper joint 2 of the pump barrel has an internal thread, which can be connected to the lower end of the inner oil pipe of the concentric oil pipe; The lower end of the pump barrel 5 has an external thread, and the lower end of the pump barrel 5 is connected to the lower joint 13 of the pump barrel; the cross section of the upper joint 2 of the pump barrel is circular, and the outer diameter of the upper joint 2 of the pump barrel is 93mm. The lower end surface of the upper joint 2 of the pump barrel is on the annular step of the inner wall of the upper joint 1 of the outer cylinder. See Figure 2. Four axial grooves are evenly distributed on the outer wall of the upper joint 2 of the pump barrel, the depth of the axial grooves is 5mm, and the axial grooves connect the upper and lower ends of the upper joint 2 of the pump barrel. See Figure 1. The cross section of the lower joint 13 of the pump barrel is circular, and the outer diameter of the lower joint 13 of the pump barrel is 83mm. Sliding fit between the outer wall of the lower joint 13 of the pump barrel and the inner wall of the outer cylinder 4 . The lower joint 13 of the pump cylinder is in the outer cylinder 4 and is connected to the lower end of the pump cylinder 5. There are four axial grooves on the outer wall of the lower joint 13 of the pump cylinder, and the axial grooves connect the upper and lower ends of the lower joint 13 of the pump cylinder. Double swimming valve assembly is arranged in pump cylinder 5, and double swimming valve assembly is made up of plunger 6, swimming valve 7, swimming valve seat 8, swimming valve baffle plate 9. The plunger 6 is cylindrical, the outer diameter of the plunger 6 is 32mm, and the length is 0.75m. The outer wall of the plunger 6 is slidingly fitted with the inner wall of the pump barrel 5, and two movable valve seats 8 are fixed in the plunger 6, and each movable valve seat 8 has a central hole with a diameter of 15mm, and the center The upper end of the hole has a conical surface. There is a swimming valve 7 (steel ball) on each swimming valve seat 8, and a swimming valve baffle plate 9 is fixed in the plunger 6 and above the swimming valve 7 of the lower end, swimming There are four through holes on the ball baffle plate 9 that moves. A connecting rod 3 is threaded on the top cover of the plunger 6, and there are two oblique holes on the top cover of the plunger 6. The bottom end of the pump cylinder 5 has a fixed valve assembly. The fixed valve assembly includes a fixed valve baffle plate 10, a fixed valve 11 and a fixed valve seat 12. The fixed valve seat 12 is fixed on the bottom of the pump barrel 5, and there is a fixed valve 11 (steel ball) on the fixed valve seat 12, and a fixed valve is fixed in the pump cylinder 5 and on the fixed valve 11. Baffle 10.

Claims (1)

1. A coalbed methane concentric tubular pump, comprising two parts, an outer cylinder assembly and an inner pump assembly; it is characterized in that: The outer cylinder assembly is mainly composed of an outer cylinder upper joint (1), an outer cylinder (4) and an outer cylinder lower joint (14); the upper end of the outer cylinder upper joint (1) has internal threads; the lower end of the outer cylinder upper joint (1) has Internal thread, the lower end of the upper joint (1) of the outer cylinder is threaded to connect the outer cylinder (4); the lower end of the outer cylinder (4) has an outer thread, and the lower end of the outer cylinder (4) is connected with the lower joint (14) of the outer cylinder; the joint on the outer cylinder (1) There is an annular step at the upper end of the inner wall; The inner pump assembly is mainly composed of the pump barrel upper joint (2), the connecting rod (3), the pump barrel (5), the double swimming valve assembly, the fixed valve assembly and the pump cylinder lower joint (13); the pump The upper end of the upper joint (2) of the cylinder has internal threads; the lower end of the upper joint (2) of the pump cylinder has external threads, and the lower end of the upper joint (2) of the pump cylinder is connected with the pump cylinder (5); the lower end of the pump cylinder (5) has external threads, and the pump The lower end of the barrel (5) is connected to the lower joint (13) of the pump barrel; the cross-section of the upper joint (2) of the pump barrel is circular, and the lower end surface of the upper joint (2) of the pump barrel is in the ring shape of the inner wall of the upper joint (1) of the outer cylinder. On the step; there is an axial groove on the outer wall of the upper joint (2) of the pump barrel, and the axial groove connects the upper and lower ends of the upper joint (2) of the pump barrel; the cross section of the lower joint (13) of the pump barrel is circular, The lower joint (13) of the pump barrel is inside the outer cylinder (4) and connected to the lower end of the pump barrel (5). There are axial grooves on the outer wall of the lower joint (13) of the pump barrel, and the axial groove connects the lower joint (13) of the pump barrel. The upper and lower ends of the upper and lower ends are connected; in the pump barrel (5), there is a double-moving valve assembly, which consists of a plunger (6), a swimming valve (7), a swimming valve seat ( 8) Composed of a swimming ball baffle (9); the plunger (6) is cylindrical, and the outer wall of the plunger (6) slides and fits with the inner wall of the pump barrel (5), and is fixed inside the plunger (6) There are two swimming valve seats (8), one swimming valve (7) on each swimming valve seat (8), and the swimming valve (7) in the plunger (6) and at the lower end ) is fixed with a swimming ball baffle (9), and a connecting rod (3) is connected to the upper part of the top cover of the plunger (6), and there is an oblique hole on the top cover of the plunger (6); 5) The bottom end has a fixed valve assembly; the fixed valve assembly includes a fixed valve baffle (10), a fixed valve (11) and a fixed valve seat (12); a fixed valve seat (12 ) is fixed on the bottom of the pump cylinder (5), and there is a fixed valve (11) on the fixed valve seat (12), and a fixed valve (11) is fixed on the fixed valve (11) in the pump cylinder (5). Val Basket (10). the

Images