An automatic plunger lift system and method for high water production wells

Abstract

The application provides a high-yield well automatic plunger lifting system and method, which comprises a downhole part and an uphole part. The downhole part comprises a casing and a tubing arranged in the casing, and the tubing is provided with a plunger. The uphole part comprises a Christmas tree arranged at a wellhead and a pipeline system connected with the Christmas tree. The pipeline system can be communicated with the tubing through a pipeline and a valve to realize production, and the tubing and the casing are communicated to realize pressure balance of the tubing and the casing, so that the plunger can be opened. The application can automatically balance casing-tubing pressure through the valve, reduce the height of liquid accumulation, and make the plunger start smoothly, so as to solve the plunger starting problem of a high-yield well. A second valve is used to realize well opening and closing control, and finally the purpose of automatic plunger gas lift liquid discharge of a high-yield well is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of high water well automatic plunger lifting system and method, belong to oil and gas exploitation field. BACKGROUND

[0002] Oil and gas well in production into middle and later period, possibly face well bottom fluid accumulation, production reduction problem, plunger gas lift technology is important means to solve wellbore fluid accumulation, with economic, efficient, clean, high automation degree characteristics.This process is mainly to use the pressure energy of gas well during shut-in period, plunger in tubing is pushed to wellhead to realize liquid discharge.However, in order to improve production rate, the shut-in time of this process usually will not be too long, pressure recovery is limited, the height of lifting liquid column is limited, only applicable to small water production well lifting, when water production is high, wellbore liquid column is high, plunger starts difficultly. SUMMARY

[0003] In view of the above technical problems existing in the prior art, the present application provides a kind of high water well automatic plunger lifting system and method, can be balanced by valve automatic casing pressure, reduce fluid accumulation height, so that plunger can be started smoothly, solve the problem of plunger starting difficultly in high water well;The second valve is used to realize well control, finally reach the purpose of automatic plunger gas lift liquid discharge in high water well.

[0004] In one aspect of the present application, a kind of high water well automatic plunger lifting system is provided, comprising:

[0005] Downhole part, the downhole part includes casing and oil pipe arranged in the casing, plunger is arranged in the oil pipe;And

[0006] Wellhead part, the wellhead part includes Christmas tree arranged in wellhead, and pipeline system connected with the Christmas tree;

[0007] Wherein, the pipeline system can realize production by pipeline and valve to communicate with the oil pipe, communicate the oil pipe and casing to realize pressure balance of oil pipe and casing, so that the liquid level of oil pipe can be reduced, and plunger can be started.

[0008] Further improvement of the present application is that the pipeline system includes first pipeline, and the first pipeline is connected with second pipeline and third pipeline respectively;

[0009] Wherein, the first pipeline is connected with production gate of the Christmas tree, and the second pipeline is connected with casing gate of the Christmas tree.

[0010] Further improvement of the present application is that the second pipeline is provided with first automatic valve, and the third pipeline is provided with second automatic valve.

[0011] The further improvement of the present application is that the gas production tree is connected with a wellhead blowout preventer.

[0012] The further improvement of the present application is that the tubing is provided with a clamp.

[0013] The further improvement of the present application is that the first automatic valve and the second automatic valve are both connected with a controller, which controls the closing, opening and switching time of the first automatic valve and the second automatic valve.

[0014] The further improvement of the present application is that the automatic valve is preferably a start-up diaphragm valve or an electric valve.

[0015] According to another aspect of the present application, an automatic plunger lifting method for a high-yield water well is also provided, which is realized by using the automatic plunger lifting system for the high-yield water well.

[0016] In the initial state, the first automatic valve is closed and the second automatic valve is opened, and the oil and gas well is in a production state;

[0017] After the second automatic valve is closed, the liquid column in the tubing is high, and the plunger is difficult to start;

[0018] The first automatic valve is opened, the tubing and the casing are connected, the tubing and the casing pressure are balanced, the tubing liquid level and the casing liquid level are balanced, and the plunger is started;

[0019] After the formation pressure is restored, the first automatic valve is closed and the second automatic valve is opened, and the oil and gas well is in a production state, and the above steps are repeated.

[0020] The further improvement of the present application is that the controller sets the closing time T of the second automatic valve off , the opening time T on , and the interval time T between the closing of the second automatic valve and the opening of the first automatic valve.

[0021] After the second automatic valve is closed, the first automatic valve is automatically opened after T time;

[0022] After T off time, the formation pressure is restored, the first automatic valve is automatically closed first, and then the second automatic valve is opened;

[0023] After T on time, the second automatic valve is closed, and the above steps are repeated.

[0024] The further improvement of the present application is that after the wellhead blowout preventer, the clamp and the plunger are removed, the system can also be used as an automatic intermittent shut-in and opening well liquid discharge system for a high-yield water well.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] The high-yield water well automatic plunger lifting system and method can significantly reduce the height of the liquid column on the plunger, solve the plunger starting problem of the high-water-yield well, and expand the technical boundary of the plunger technology. The controller is used for automatic control, and the liquid of the high-water-yield well can be discharged only by relying on the self energy without manual assistance. The method has the advantages of less equipment accessories, low investment, high automation degree, and good reliability. BRIEF DESCRIPTION OF DRAWINGS

[0027] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the drawings:

[0028] Figure 1 The structure schematic diagram of the high-yield water well automatic plunger lifting system of one embodiment of the present application is shown. The first automatic valve and the second automatic valve are both closed.

[0029] Figure 2 The structure schematic diagram of the high-yield water well automatic plunger lifting system of one embodiment of the present application is shown.

[0030] The first automatic valve is shown in the open state.

[0031] Figure 3 The structure schematic diagram of the high-yield water well automatic plunger lifting system of one embodiment of the present application is shown.

[0032] The second automatic valve is shown in the open state.

[0033] The meanings of the reference signs in the drawings are as follows:

[0034] 1, oil pipe, 2, casing, 3, gas production tree, 4, first pipeline, 5, second pipeline, 6, third pipeline, 7, first automatic valve, 8, second automatic valve, 9, wellhead blowout preventer, 10, plunger, 11, retainer, 12, liquid column. DETAILED DESCRIPTION

[0035] In order to make the technical solutions and advantages of the present application clearer, the exemplary embodiments of the present application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. And in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0036] Figure 1The high-yield water well automatic plunger lifting system according to an embodiment of the present application is schematically shown. The system includes an uphole part, which includes a casing 2 and a tubing 1. The lower part of the casing 2 and the tubing 1 is provided with a communication port, and the tubing 1 is provided with a plunger 10. The plunger 10 can move in the tubing 1, and push the liquid in the tubing 1 to the wellhead to be discharged by moving upward, thereby achieving liquid discharge. The high-yield water well automatic plunger lifting system according to the embodiment further includes an uphole part, which includes a Christmas tree 3 provided at the wellhead, and the Christmas tree 3 is connected to the casing 2 and the tubing 1. The uphole part further includes a pipeline system. The pipeline system can connect the Christmas tree 3 through pipelines and valves to achieve production.

[0037] The pipeline system can connect the tubing 1 through pipelines and valves to achieve production, and connect the tubing 1 and the casing 2 to balance the pressure of the tubing 1 and the casing 2, so that the liquid level of the tubing 2 can be lowered, and the plunger 10 can be started. The pipeline system can be divided into several states according to the opening and closing of the valves and the on-off of the pipelines, which are production state, only the tubing 1 is connected; closed state, the tubing 1 and the casing 2 are both closed, and the liquid level in the tubing 1 is high; and tubing-casing connection state, the tubing 1 and the casing 2 are connected to balance the pressure between the tubing 1 and the casing 2, so that the plunger 10 can be started.

[0038] In an embodiment, the pipeline system includes a first pipeline 4, a second pipeline 5 and a third pipeline 6. One end of the first pipeline 4 is connected to a production gate of the Christmas tree 3, and the other end is connected to the second pipeline 5 and the third pipeline 6 through a tee joint. The second pipeline 5 is connected to a casing 2 gate of the Christmas tree 3.

[0039] In a preferred embodiment, the second pipeline 5 is provided with a first automatic valve 7, which controls the on-off of the second pipeline 5; and the third pipeline 6 is provided with a second automatic valve 8, which controls the on-off of the third pipeline 6.

[0040] In the high-yield water well automatic plunger lifting system according to the embodiment, when the first automatic valve 7 is closed and the second automatic valve 8 is opened, the second pipeline 5 is in a closed state, the first pipeline 4 and the third pipeline 6 are connected, and the liquid in the tubing 1 flows out through the Christmas tree 3, the first pipeline 4 and the third pipeline 6. When the first automatic valve 7 is opened and the second automatic valve 8 is closed, the third pipeline 6 is closed, the first pipeline 4 and the second pipeline 5 are connected, the production gate and the casing 2 gate are connected, thereby establishing the communication port between the casing 2 and the tubing 1 at the wellhead, connecting the casing 2 and the tubing 1, balancing the pressure inside, and making the liquid levels of the casing 2 and the tubing 1 flat, so that the plunger 10 is easy to start.

[0041] In one embodiment, a blowout pipe 9 is connected to the Christmas tree 3. The blowout pipe 9 is installed on the Christmas tree 3 for placing the blowout accident.

[0042] In one embodiment, a clamp 11 is arranged in the tubing 1, which functions as a positioner and buffer for the plunger 10.

[0043] The first automatic valve 7 and the second automatic valve 8 are both connected to a controller, which controls the closing, opening and switching time of the first automatic valve 7 and the second automatic valve 8. The controller sets the closing time T off , the opening time T on and the interval time T of the second automatic valve 8 closing to the first automatic valve 7 opening. By setting the switching time of the second automatic valve 8 and the first automatic valve 7, the flow of the whole automatic plunger lifting method can be controlled, and automatic control is realized without personnel on duty.

[0044] The automatic valve is preferably a start-up diaphragm valve or an electric valve.

[0045] According to another aspect of the present application, an automatic plunger lifting method for a high water yield well is also provided, which uses the automatic plunger lifting system for a high water yield well according to the above embodiment, and comprises:

[0046] In the initial state, the first automatic valve 7 is closed and the second automatic valve 8 is opened, and the oil and gas well is in a production state;

[0047] After the second automatic valve 8 is closed, the liquid column in the tubing 1 is high, and the plunger 10 is difficult to start;

[0048] The first automatic valve 7 is opened, the tubing 1 and the casing 2 are communicated, the tubing 1 and the casing 2 are pressure balanced, the liquid level of the tubing 1 is balanced with the liquid level of the casing 2, and the plunger 10 is started;

[0049] After the formation pressure is restored, the first automatic valve 7 is closed and the second automatic valve 8 is opened, and the oil and gas well is in a production state again, and the above steps are repeated.

[0050] In one preferred embodiment, the controller sets the closing time T off , the opening time T on and the interval time T of the second automatic valve 8 closing to the first automatic valve 7 opening.

[0051] After the second automatic valve 8 is closed, the first automatic valve 7 is automatically opened after T time;

[0052] After T off time, the formation pressure is restored, the first automatic valve 7 is automatically closed first, and the second automatic valve 8 is opened again.

[0053] After T on The second automatic valve 8 is closed after T, and the above steps are repeated.

[0054] Automatic control can be achieved through the controller, and the entire process of the automatic plunger lifting method can be controlled to achieve automatic control without personnel on duty.

[0055] In a preferred embodiment, after the wellhead blowout pipe 9, the stopper 11 and the plunger 10 are removed, the automatic intermittent shut-in and liquid discharge system for high-yield water wells can also be used.

[0056] In a specific embodiment, the automatic plunger lifting method for high-yield water wells comprises the following steps:

[0057] Step one, in the initial state, the first automatic valve 7 is closed, the second automatic valve 8 is opened, and the oil and gas well is in production.

[0058] Step two, set the closing time T off , the opening time T on , and the valve start interval time T of the second automatic valve 8 through the controller, and then trigger the automatic mode.

[0059] Step three, the second automatic valve 8 is automatically closed, at this time the liquid column of the oil pipe 1 is high, and the plunger 10 is difficult to start Figure 1 .

[0060] Step four, after T, the first automatic valve 7 is automatically opened, the oil and casing 2 are connected to form a communicating vessel, the casing 2 gas enters the oil pipe 1, the oil pipe 1 and the casing 2 are balanced, the oil pipe 1 liquid level is lowered and leveled with the casing 2 liquid level, at this time the plunger 10 is easier to start Figure 2 .

[0061] Step five, after T off , the formation pressure is recovered, the first automatic valve 7 is automatically closed first, and the second automatic valve 8 is automatically opened, the well is opened for production, and the plunger 10 starts to rise from the bottom of the well Figure 3 .

[0062] Step six, after T on , return to step three and repeat the above process.

[0063] According to the method described in the embodiment, the height of the liquid column above the plunger 10 can be significantly reduced, the plunger 10 starting problem of large water wells can be solved, and the technical boundary of the plunger 10 can be widened. Through automatic control by the controller, manual assistance is not required, and only self-energy can achieve liquid discharge of large water wells. The method described in the embodiment has the advantages of less equipment accessories, low investment, high automation and good reliability.

[0064] While the preferred embodiments of the application have been described, additional variations and modifications can be made to these embodiments by those skilled in the art once they have the benefit of the foregoing description. It is therefore intended that the appended claims shall cover all such modifications and / or changes as fall within the true spirit and scope of the application.

Claims

1. A high water production well automatic plunger lift system characterized by, It comprises: a downhole part, which comprises a casing (2) and a tubing (1) arranged in the casing (2), and a plunger (10) arranged in the tubing (1); and an uphole part, which comprises a Christmas tree (3) arranged at a wellhead, and a pipeline system connected to the Christmas tree (3); wherein the pipeline system can communicate with the tubing (1) through a pipeline and a valve to realize production, and communicate with the tubing (1) and the casing (2) to realize pressure balance of the tubing (1) and the casing (2), so that the liquid level of the tubing (1) can be lowered and the plunger (10) can be started; the pipeline system comprises a first pipeline (4), a second pipeline (5) and a third pipeline (6), one end of the first pipeline (4) is connected to a production gate of the Christmas tree (3), the other end is connected to the second pipeline (5) and the third pipeline (6) through a tee joint, and the second pipeline (5) is connected to a casing (2) gate of the Christmas tree (3); a first automatic valve (7) is arranged on the second pipeline (5), and a second automatic valve (8) is arranged on the third pipeline (6); a wellhead blowout preventer is connected to the Christmas tree (3).

2. The high water production well automatic plunger lifting system of claim 1, wherein, A stopper (11) is arranged in the tubing (1).

3. The high water production well automatic plunger lifting system of claim 2, wherein, The first automatic valve (7) and the second automatic valve (8) are both connected to a controller, and the controller controls closing, opening and switching time of the first automatic valve (7) and the second automatic valve (8).

4. The high water production well automatic plunger lifting system of claim 3, wherein, The automatic valve is a pneumatic diaphragm valve or an electric valve.

5. A high water production well automatic plunger lift method characterized by, The automatic plunger lifting system for high water yield wells is realized by using the system according to any one of claims 1 to 4, which comprises: in an initial state, the first automatic valve (7) is closed, the second automatic valve (8) is opened, and the oil and gas well is in a production state; after the second automatic valve (8) is closed, the liquid column (12) in the tubing (1) is high, and the plunger (10) is difficult to start; the first automatic valve (7) is opened, the tubing (1) and the casing (2) are communicated, the tubing (1) and the casing (2) are pressure balanced, the liquid level of the tubing (1) is balanced with the liquid level of the casing (2), and the plunger (10) is started; after the formation pressure is restored, the first automatic valve (7) is closed, the second automatic valve (8) is opened, the oil and gas well is in a production state again, and the above steps are repeated; The controller sets the closing time T of the second automatic valve (8) off , the opening time T on , and the interval time T from the closing of the second automatic valve (8) to the opening of the first automatic valve (7). after the second automatic valve (8) is closed, the first automatic valve (7) is automatically opened after T time; After T off The formation pressure is recovered after a long time, the first automatic valve (7) is automatically closed first, and the second automatic valve (8) is opened again. After T on the second automatic valve (8) is closed and the above steps are repeated.

6. The high water production well automatic plunger lifting method of claim 5, wherein, after the wellhead blowout pipe (9), the stopper (11) and the plunger (10) are removed, the system can also be used as an automatic intermittent shut-in and liquid discharge system for high water yield wells.

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