CN104747122B - A kind of choke valve controlled for underground liquid level - Google Patents

Abstract

The invention discloses a throttle valve for downhole liquid level control, which comprises a valve body, a valve core, an adjusting bolt, a compression spring, a sealing ring, and a limit gasket; the radial direction of the valve body is processed with a valve core hole; The core is a slide valve structure, and the valve core is processed with oil grooves, sealing ring grooves and reinjection water grooves; the valve body is axially processed with reinjection water channels and gas production channels; the adjusting bolt can adjust the force of the compression spring; the limit gasket is processed There is a through hole, which communicates the outer annular space of the valve body with the right end of the valve core. The throttle valve is simple in structure and convenient in connection, and is used for downhole liquid level control of drainage and gas production wells so as to prevent dry grinding of the reinjection pump and cause the pump to burn out.

Description

A throttling valve for downhole liquid level control

technical field

The invention relates to the field of choke valves, in particular to a choke valve used for downhole liquid level control in downhole gas-liquid separation and co-well reinjection natural gas wells.

Background technique

Water flooding of gas wells is one of the main problems restricting natural gas production, especially in the process of exploitation of shallow natural gas reservoirs, the contradiction caused by insufficient energy of gas reservoirs is more prominent. Using downhole gas-liquid separation and reinjection technology, the water in natural gas can be separated downhole and directly reinjected into the formation. Downhole separation and reinjection technology has the following advantages compared with other methods of drainage and gas recovery: ①It can greatly reduce the liquid production rate and water content of high water-cut gas wells, thereby greatly reducing the lifting cost and operating cost; ②Save the cost of surface water treatment , reduce the use of toxic chemicals such as preservatives, anti-scaling agents and flocculants, and reduce environmental pollution; ③ prolong the economic life of gas wells with high water content that should be scrapped, thereby prolonging the production period of gas fields; ④ reduce the use of In terms of the number of water injection wells for reinjection of produced water, it saves infrastructure investment costs and expansion costs for additional surface equipment; in view of its many advantages, downhole gas-liquid separation and reinjection technology has gradually attracted people's attention, and gradually underground separation and return Note system for equipment development and testing.

In gas wells using downhole separation and reinjection technology, when downhole pumps (such as screw pumps) are used for reinjection, the pump is required to have sufficient water supply to prevent the pump from being pumped out and dry grinding, which will cause the pump to burn out. Therefore, the water absorption level of the pump control is crucial. Nowadays, there are two main methods of downhole liquid level detection and control. One is the acoustic wave detection method, which can only measure the static liquid level of the oil well, but cannot detect the water flooded liquid level of the gas well that is out of the casing at any time; the other is the downhole pressure sensor. , due to the need to place downhole for a long time and real-time data transmission, the downhole sensor has the disadvantages of short life and high cost.

Contents of the invention

The object of the present invention is to address the shortcomings of the prior art and provide a throttle valve for downhole liquid level control that can detect the flooded liquid level of a gas well that is out of the casing, has a simple structure, is convenient to connect, and has a long service life.

The present invention adopts following design scheme:

A throttle valve for downhole liquid level control, including a valve body and a valve core, the valve body 4 is cylindrical, the middle of the valve body 4 is provided with a valve core hole radially through the axis, on the valve body 4, The lower part is respectively provided with U-shaped grooves along the axis, the upper and lower U-shaped grooves are axially provided with upper and lower gas production channels 16, and the upper and lower U-shaped grooves are symmetrically provided with return water channels 15 connected with the valve core hole. On the periphery of the lower U-shaped groove, a balance air passage 7 connected with the valve core hole is provided; the valve core 13 is a slide valve structure that is sliding and sealingly matched with the valve core hole, and an oil groove 11 and a refilling water groove 10 are set on the outer surface of the valve core 13 , the return water groove 10 is matched with the return water channel 15; the valve core 13 is limited in the valve core hole by the compression spring 6 and the adjustment bolt 5 at one end of the valve core 13, and the working area of the compression spring 6 communicates with the balance air channel 7 The other end of the spool 13 is limited to the spool 13 in the spool hole by the spacer 14, the spacer 14 is processed with a through hole, and the outer annular space of the valve body 4 is connected to the spool hole at the spool 13 end. Gap connectivity.

The above program also includes:

An oil groove 11 and a seal ring groove are also provided on the outer surface of the valve core 13, and a seal ring 12 sealingly matched with the valve core hole is arranged in the seal ring groove.

The upper and lower U-shaped grooves of the valve body 4 are respectively plugged and sealed with inner pipes.

The upper and lower ends of the valve body 4 are respectively connected with outer pipes, and the junction of the inner pipe and the valve body 4 is provided with a sealing ring.

The annular space formed between the upper and lower inner and outer pipes of the valve body 4 communicates with the gas production channel 16 .

The advantages of the present invention are: (1) simple structure and convenient processing. (2) The connection is convenient, directly connected under the oil pipe, without increasing the radial size of the equipment. (3) The sliding friction of the slide valve is small, and the liquid level control precision is high.

Description of drawings

Fig. 1 is a schematic diagram of installation of a throttle valve for downhole liquid level control according to the present invention.

Fig. 2 is a cross-sectional view of the valve body A-A of a throttle valve used for downhole liquid level control according to the present invention.

Fig. 3 is a top view of a throttle valve used for downhole liquid level control according to the present invention.

In the figure 1. Outer pipe A, 2. Inner pipe A, 3. Sealing ring, 4. Valve body, 5. Adjusting bolt, 6. Compression spring, 7. Balance airway, 8. Inner pipe B, 9. Outer pipe B, 10. Reinjection water groove, 11. Oil tank, 12. Seal ring, 13. Valve core, 14. Limit gasket, 15. Reinjection water channel, 16. Gas production channel.

detailed description

Below in conjunction with accompanying drawing 1, accompanying drawing 2 and accompanying drawing 3 the present invention will be further described:

The valve body 4 of a throttle valve used for underground liquid level control is cylindrical, and the radial direction of the valve body 4 is processed with a valve core hole, and the valve core 13 and the valve core hole are sealed by a sealing ring 12; one end of the valve core 13 is Compression spring 6 and adjusting bolt 5, the other end is limit washer 14; Adjusting bolt 5 can adjust the active force of compression spring 6 and as the left limit of spool 13; Limit washer 14 is the right limit of spool 13 position; the limit gasket 14 is processed with a through hole, which connects the outer annular space of the valve body 4 with the right end of the valve core 13; groove.

The upper part of the valve body 4 is connected to the outer pipe A1, and there is an inner pipe A2 inside the outer pipe A1, and the inner pipe A2 is connected to the U-shaped groove on the upper part of the valve body 4; The tube B8 is connected to the U-shaped groove at the lower part of the valve body 4; the valve body 4 is processed with a gas-producing channel 16, which is an axial through hole of the valve body 4; an annular space A is formed between the outer tube A1 and the inner tube A2, An annular space B is formed between the outer tube B9 and the inner tube B8, and the annular space A communicates with the annular space B through the gas production channel 16; The hole forms a communication passage between the inner pipe A2 and the inner pipe B8; the valve body 4 is axially processed with a balance air passage 7, and the balance air passage 7 connects the space on the left side of the valve core 13 with the annular space B.

In specific use, the upper part of the outer pipe A1 is connected to the downhole separator, and the upper part of the downhole separator is connected to the reinjection pump; the lower part of the outer pipe B9 is connected to the casing isolation cup; the production layer gas passes through the annular space B, the gas production channel 16 and the annular space A When it reaches the downhole separator, the water separated by the downhole separator accumulates downwards and accumulates in the upper part of the casing packing cup and the outer annular space of the upper outer pipe A1; The water is connected, and the pressure acting on the right side of the valve core 13 is the separated water to form the water column pressure and the air pressure on the upper part of the separated water; The pressure on the left is the spring pressure and the air pressure of the annular space B; the reinjection pump sucks the separated water, and then reinjects the separated water downward along the inner pipe A2, and the reinjected water passes through the inner channel of the inner pipe A2, the reinjection water channel 15, and the reinjection water in turn The inner space of the groove 10 and the inner pipe B8; when the separated water level is at a high level, the pressure on the right side of the spool 13 is greater than the pressure on the left side, the spool 13 is fully open, the throttling area is the largest, and the reinjection pressure of the reinjection pump is relatively high. Small; as the separated water level drops, the spring on the left side of the spool 13 gradually pushes the spool 13 to move to the right, the throttling area decreases, and the reinjection pressure of the reinjection pump continues to increase. The change of the reinjection pressure of the reinjection pump can be judged by the current change of the driving motor of the reinjection pump at the gas production wellhead or the pressure change of the pressure measuring port on the ground connected to the discharge port of the reinjection pump, so that the current or the pressure change of the pressure measuring port can affect the The back pressure pump starts and stops.

Claims (5)

1. a kind of choke valve controlled for underground liquid level, including valve body and valve element, it is characterized in that：The valve body (4) is in cylinder Shape, the middle part of valve body (4) radially opens up the spool bore through axle center, and valve body (4) upper and lower part opens up U-type groove respectively along axle center, Upper and lower U-type groove periphery axially opens up symmetrical open up in the aerogenesis passage (16) of upper and lower insertion, upper and lower U-type groove and passed through with spool bore Logical backwater channel (15), the air pressure balance duct (7) with spool bore insertion is opened up in lower U-type groove periphery；The valve element (13) be with Spool bore is slidingly sealed the sliding valve structure of cooperation, and re-injection water groove (10), re-injection water groove are opened up in valve element (13) outer surface (10) coordinate with backwater channel (15) formation；In valve element (13) one end by compression spring (6) and regulating bolt (5) by valve element (13) it is limited in spool bore, and compression spring (6) workspace is connected with air pressure balance duct (7)；Valve element (13) other end passes through Valve element (13) is limited in spool bore by spacing shim (14), and spacing shim (14) is machined with through hole, by the outside of valve body (4) The valve element interporal lacuna that annular space is held with the valve element (13) is connected.

2. the choke valve according to claim 1 controlled for underground liquid level, it is characterized in that：In valve element (13) outer surface Also open up and sealing ring (12) is set in oil groove (11) and o-ring groove, o-ring groove.

3. the choke valve according to claim 1 or 2 controlled for underground liquid level, it is characterized in that：Valve body (4) is U-shaped up and down Grafting is sealed with inner tube respectively in groove.

4. the choke valve according to claim 3 controlled for underground liquid level, it is characterized in that：Valve body (4) upper and lower side part Outer tube, inner tube and valve body are not connected with（4）Joint portion is provided with sealing ring.

5. the choke valve according to claim 4 controlled for underground liquid level, it is characterized in that：It is inside and outside above and below valve body (4) The annular space constituted between pipe is connected with aerogenesis passage (16).