A high gas-oil ratio oil wellhead dosing device and method

Abstract

The present invention provides a wellhead dosing device and method for a high gas-oil ratio oil well, comprising a piston, a vertical working cylinder, a one-way valve, a dosing tank and a dosing connecting pipe; the medicine liquid in the dosing tank is pumped into the vertical working cylinder through the upward movement of the piston, and then the medicine liquid is pressed into the annulus between the oil pipe and the casing of the oil well through the downward movement of the piston, and then the medicine liquid is pumped into the interior of the oil pipe through the oil pump, and then the oil pipe is prevented from scaling by the medicine liquid; the dosing device realizes the extraction and pressing of the medicine liquid through the piston, and can accurately control the dosing amount of the medicine liquid, avoiding the problem of waste of the medicine liquid or insufficient dosing amount, and at the same time, the medicine liquid is pressed in through a certain pressure, which solves the problem that the medicine liquid cannot be added due to excessive pressure in the oil well, and secondly, the reciprocating movement of the piston ensures the continuity of dosing.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield wax cleaning and scale prevention, and specifically relates to a wellhead dosing device and method for a high gas-oil ratio oil well. Background Art

[0002] Daily dosing of oil wells is one of the most commonly used maintenance measures to maintain normal production of oil wells. It can effectively prevent the pipe and rod stuck caused by wax and scaling in oil wells, reduce the load of extraction equipment, extend the maintenance-free period of oil wells, and reduce mining costs. At present, the commonly used dosing methods are wellhead annulus drip dosing and vehicle-mounted dosing devices. The annulus drip dosing method is difficult for some high gas-oil ratio and high pressure wells. The vehicle-mounted dosing device has problems such as complex structure, frequent failures, difficult relocation and maintenance, and not light enough.

[0003] Based on the above problems, it is necessary to develop a high gas-oil ratio oil wellhead dosing device and method in order to solve the problems existing in the prior art. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a device and method for adding chemicals at the wellhead of an oil well with a high gas-oil ratio, which utilizes the excess energy of the oil pumping unit itself to achieve automatic adding chemicals.

[0005] The present invention is achieved through the following technical solutions:

[0006] A wellhead dosing device for a high gas-oil ratio oil well, comprising a piston, a vertical working cylinder, a one-way valve, a dosing tank and a dosing connecting pipe;

[0007] The outlet of the dosing tank is connected to the lower end of the vertical working cylinder through a one-way valve, a piston is arranged in the vertical working cylinder, one end of the dosing connecting pipe is arranged at the outlet end of the one-way valve and connected to the lower end of the vertical working cylinder, and the other end of the dosing connecting pipe is connected to the oil well;

[0008] When the piston moves upward, the liquid medicine in the dosing tank is pumped into the vertical working cylinder through the one-way valve. When the piston moves upward, the liquid medicine is pressed into the oil well through the dosing connecting pipe.

[0009] Preferably, the piston is connected to the oil pump transmission device through a piston push rod.

[0010] Preferably, the dosing tank is arranged above the wellhead, the outlet of the dosing tank is connected to the lower end of the vertical working cylinder through a dosing pipe, and the dosing pipe is arranged obliquely downward from the dosing tank to the wellhead.

[0011] Preferably, the drug outlet pipe and the inlet section of the drug adding connecting pipe are arranged at an angle, and the angle is an acute angle.

[0012] Preferably, the lower end of the vertical working cylinder, the outlet end of the one-way valve and the inlet end of the dosing connecting pipe are connected via a three-way valve.

[0013] Preferably, the drug adding connecting pipe is a U-shaped structure.

[0014] Preferably, a control valve is also provided at the outlet end of the drug adding connecting pipe.

[0015] Preferably, the oil well is also provided with an oil pumping device, which is connected to the oil pumping unit transmission device.

[0016] A dosing method for a wellhead dosing device of a high gas-oil ratio oil well, comprising the following steps:

[0017] Step 1: Start the oil pump, and the oil pump transmission device drives the piston upward to pump the liquid into the vertical working cylinder;

[0018] Step 2: The pumping unit drives the piston upward, presses the liquid medicine in the vertical working cylinder into the annulus between the oil pipe and the sleeve, and the liquid medicine flows into the lower end of the oil well along the annulus and mixes with the oil;

[0019] Step 3: The pumping unit moves upward, and the oil pump draws the mixture of liquid medicine and oil into the oil pipe;

[0020] Step 4: Repeat steps 1-3 until the dosing is completed.

[0021] Preferably, the method for determining the inner diameter D of the vertical working cylinder is as follows:

[0022]

[0023] Among them, Q is the amount of chemicals added to the oil well; s is the stroke; and n is the number of strokes.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] The present invention provides a high gas-oil ratio oil well wellhead dosing device, which pumps the medicine liquid in the dosing tank into the vertical working cylinder through the upward movement of the piston, and then presses the medicine liquid into the annulus between the oil pipe and the casing of the oil well through the downward movement of the piston, and then pumps the medicine liquid into the interior of the oil pipe through the oil pump, and then prevents the oil pipe from scaling through the medicine liquid; the dosing device realizes the extraction and pressing of the medicine liquid through the piston, and can accurately control the dosing amount of the medicine liquid, avoiding the problem of waste of the medicine liquid or insufficient dosing amount, and at the same time, the medicine liquid is pressed in through a certain pressure, which solves the problem that the medicine liquid cannot be added due to excessive pressure in the oil well, and secondly, the reciprocating movement of the piston ensures the continuity of dosing.

[0026] Furthermore, by driving the piston to reciprocate through the oil pump, there is no need to add an additional power system, thereby improving the utilization rate of the pumping unit power.

[0027] Furthermore, the medicine outlet pipe is arranged to be tilted downward, so as to reduce the pressure of extracting the medicine liquid, and make the medicine liquid flow into the vertical working cylinder under the cooperation of gravity.

[0028] Furthermore, the medicine outlet pipe and the inlet section of the medicine adding connecting pipe are arranged at an acute angle to ensure that the medicine liquid can be drawn into the vertical working cylinder and injected into the medicine adding connecting pipe under pressure, thereby ensuring that the medicine liquid enters the annulus under pressure.

[0029] Furthermore, the capacity of the vertical working cylinder is determined by calculation, and then the amount of medicine added in each stroke is accurately determined to avoid waste of liquid medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the dosing device of the present invention.

[0031] In the figure: 1, oil pumping unit transmission device, 2, piston push rod, 3, piston, 4, vertical working cylinder, 5, connecting tee, 6, check valve, 7, dosing tank, 8, dosing connecting pipe, 9, control valve, 10, sucker rod, 11, oil pump, 12, screen pipe, 13, screw plug, 14, oil pipe outlet joint. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with the accompanying drawings, which are intended to explain the present invention rather than to limit it.

[0033] See also Figure 1 A dosing device for a wellhead of an oil well with a high gas-oil ratio comprises a pumping unit transmission device 1, a piston 3, a vertical working cylinder 4, a one-way valve 6, a dosing tank 7, a dosing connecting pipe 8 and a control valve 9.

[0034] The outlet of the dosing tank 7 is connected to the lower end of the vertical working cylinder 4 through a one-way valve 6. The piston 3 is arranged in the vertical working cylinder 4. The piston 3 is connected to the oil pumping unit transmission device 1 through a piston push rod 2. The oil pumping unit transmission device 1 drives the piston to reciprocate up and down in the vertical working cylinder 4. One end of the dosing connecting pipe 8 is arranged at the outlet end of the one-way valve 6 and is connected to the lower end of the vertical working cylinder 4. The other end of the dosing connecting pipe 8 is connected to the annulus between the oil pipe and the sleeve.

[0035] When the piston moves upward, the liquid medicine in the dosing tank 7 is pumped into the vertical working cylinder 4 through the one-way valve 6. When the piston moves upward, the liquid medicine is pressed into the annulus between the oil pipe and the sleeve through the dosing connecting pipe 8.

[0036] Specifically, the dosing tank 7 is arranged above the wellbore mouth, the outlet of the dosing tank 7 is connected to the lower end of the vertical working cylinder 4 through a discharge pipe, a one-way valve 6 is arranged on the discharge pipe, and the discharge pipe is arranged to be inclined downward from the dosing tank to the wellbore.

[0037] The lower end of the vertical working cylinder 4 , the outlet end of the medicine outlet pipe and the inlet of the medicine adding connecting pipe 8 are connected through a three-way valve 5 .

[0038] The inner diameter D of the vertical working cylinder 4 is set according to the amount of drug added to the oil well, and the formula is as follows:

[0039]

[0040] In the formula: Q is the amount of chemicals added to the oil well; s is the stroke; n is the number of strokes.

[0041] The dosing connecting pipe 8 is a U-shaped structure, an inlet of which is connected to the three-way valve 5, and the other end is connected to the side wall of the wellbore.

[0042] The dosing connecting pipe 8 includes a feed pipe, a guide pipe and a discharge pipe which are connected in sequence. The inlet of the feed pipe is connected to the three-way valve, and the feed pipe is located below the discharge pipe. The discharge pipe and the feed pipe are arranged at an angle, which is an acute angle. The angle between the vertical working cylinder 4 and the discharge pipe is greater than or equal to 90°.

[0043] The discharge pipe is located below the feed pipe, the outlet of which is connected to the wellbore, and a control valve 9 is also provided on the discharge pipe.

[0044] An oil pumping device is also provided in the wellbore, which includes an oil pumping rod 10 , an oil pump 11 and a screen pipe 12 .

[0045] The upper end of the sucker rod 10 is connected to the oil pump transmission device 1, and the lower end thereof is connected to the oil pump 11. The screen pipe 12 is connected to the pump barrel of the oil pump 11. A wire plug 13 is provided at the lower end of the pump barrel. The well fluid in the pump barrel of the oil pump 11 enters the oil pipe and is pumped to the ground, and enters the gathering and transportation process from the oil pipe outlet joint 14.

[0046] The present invention provides a dosing method for a wellhead dosing device of an oil well with a high gas-oil ratio, comprising the following steps:

[0047] 1. Determine the inner diameter of the vertical working cylinder.

[0048] 2. Connect the vertical working cylinder to the dosing connecting pipe and the drug outlet pipe through a three-way valve. The drug outlet pipe is connected to the drug outlet tank, and a one-way valve 6 is set on the drug outlet pipe. The outlet of the dosing connecting pipe is connected to the wellbore, and a control valve is set at the outlet end of the dosing connecting pipe.

[0049] 3. A piston is arranged in the vertical working cylinder, and the piston is connected to the oil pump transmission device through a piston push rod.

[0050] 4. The dosing tank 7 is filled with the chemicals required for the oil well.

[0051] 5. Open the control valve 9 and the check valve 6, start the pumping unit, and the pumping unit transmission device 1 moves up and down;

[0052] During the upward stroke: the piston push rod 2 drives the piston 3 in the vertical working cylinder 4 upward, and the liquid medicine in the dosing tank 7 enters the vertical working cylinder 4 through the check valve 6 under the action of the "U-tube" principle, and at the same time drives the sucker rod 10 upward, and the sucker rod 10 further drives the piston of the oil pump 11 upward, and the well fluid enters the pump barrel of the oil pump 11 after passing through the screen pipe 12.

[0053] During the down stroke: the piston push rod 2 drives the piston 3 in the vertical working cylinder 4 downward, and the piston 3 pushes the liquid medicine in the vertical working cylinder 4 into the wellbore of the oil well through the dosing connecting pipe 8; at the same time, it drives the sucker rod 10 downward, and the sucker rod 10 further drives the piston of the oil pump 11 downward, and the well fluid in the pump barrel of the oil pump 11 enters the oil pipe and is pumped to the ground, and enters the gathering and transportation process from the oil pipe outlet joint 14.

[0054] 6. Close the control valve 9 and the check valve 6, and the dosing is finished.

[0055] The present invention provides a high gas-oil ratio oil well wellhead dosing device, which pumps the medicine liquid in the dosing tank into the vertical working cylinder through the upward movement of the piston, and then presses the medicine liquid into the annulus between the oil pipe and the casing of the oil well through the downward movement of the piston, and then pumps the medicine liquid into the interior of the oil pipe through the oil pump, and then prevents the oil pipe from scaling through the medicine liquid; the dosing device realizes the extraction and pressing of the medicine liquid through the piston, and can accurately control the dosing amount of the medicine liquid, avoiding the problem of waste of the medicine liquid or insufficient dosing amount, and at the same time, the medicine liquid is pressed in through a certain pressure, which solves the problem that the medicine liquid cannot be added due to excessive pressure in the oil well, and secondly, the reciprocating movement of the piston ensures the continuity of dosing.

[0056] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A high gas-oil ratio oil well wellhead dosing device, characterized in that: It comprises a piston (3), a vertical working cylinder (4), a one-way valve (6), a dosing tank (7) and a dosing connecting pipe (8); The outlet of the dosing tank (7) is connected to the lower end of the vertical working cylinder (4) through a one-way valve (6), the piston (3) is arranged in the vertical working cylinder (4), one end of the dosing connecting pipe (8) is arranged at the outlet end of the one-way valve (6) and connected to the lower end of the vertical working cylinder (4), and the other end of the dosing connecting pipe (8) is connected to the annulus between the oil pipe and the sleeve of the oil well; When the piston moves upward, the liquid medicine in the medicine adding tank (7) is pumped into the vertical working cylinder (4) through the one-way valve (6); when the piston moves downward, the liquid medicine is pressed into the oil well through the medicine adding connecting pipe (8); The dosing tank (7) is arranged above the wellhead, the outlet of the dosing tank (7) is connected to the lower end of the vertical working cylinder (4) through a dosing pipe, and the dosing pipe is arranged to be inclined downward from the dosing tank toward the wellhead, and the dosing pipe and the inlet section of the dosing connecting pipe (8) are arranged at an angle, and the angle is an acute angle; The drug adding connecting pipe (8) is a U-shaped structure; The lower end of the vertical working cylinder (4), the outlet end of the one-way valve and the inlet of the dosing connecting pipe (8) are connected via a three-way valve (5); the outlet end of the dosing connecting pipe (8) is also provided with a control valve (9); The dosing method of the high gas-oil ratio oil well wellhead dosing device comprises the following steps: Step 1: Start the oil pump, and the oil pump transmission device (1) drives the piston upward to pump the liquid medicine into the vertical working cylinder (4); The inner diameter of the vertical working cylinder (4) D The method of determining is as follows: in, Q Adding chemicals to oil wells; s for stroke; n For the rush; Step 2: The pumping unit drives the piston downward, and the liquid medicine in the vertical working cylinder (4) is pressed into the annulus between the oil pipe and the sleeve. The liquid medicine flows along the annulus into the lower end of the oil well and mixes with the oil; Step 3: The pumping unit moves upward, and the oil pump draws the mixture of liquid medicine and oil into the oil pipe; Step 4: Repeat steps 1-3 until the dosing is completed.

2. A high gas-oil ratio oil well wellhead dosing device according to claim 1, characterized in that: The piston (3) is connected to the oil pump transmission device (1) via a piston push rod (2).

3. The high gas-oil ratio oil well wellhead dosing device according to claim 1, characterized in that: The oil well is also provided with an oil pumping device, which is connected to the oil pumping unit transmission device (1).

Images