A self-powered wax removal device and method

Abstract

The application discloses a self-power generation wax removing device and method, and the device comprises an oil layer sleeve, an annular space protective liquid, a gas and oil extraction pipe column, an electric wire, a pipeline control unit, a generator and a wellhead output pipeline, wherein the gas and oil extraction pipe column comprises an insulation layer, the gas and oil extraction pipe column is arranged in the oil layer sleeve, and the annular space protective liquid is filled between the gas and oil extraction pipe column and the oil layer sleeve; one end of the wellhead output pipeline is arranged in the gas and oil extraction pipe column, and the other end of the wellhead output pipeline is connected with a gas and oil receiving device and the generator through the pipeline control unit; one end of the electric wire is connected with the annular space protective liquid, and the other end of the electric wire is connected with the generator. The application utilizes the pressure difference between an oil nozzle and a downstream low-pressure area, adds a self-power generation device, and the power generation device and the circuit are completely in a closed and anoxic environment, and whether power generation is automatically controlled according to the temperature of the extracted fluid by a controller.

Description

Technical Field

[0001] This invention relates to the field of oil trial production and development technology, and in particular to a self-generating dewaxing device and method. Background Technology

[0002] During oil and gas pilot production or development, if the formation fluid has a high wax content, as it flows upward in the tubing, the temperature and pressure decrease. When the wax reaches the precipitation point, the wax in the oil and condensate will crystallize and precipitate, causing blockage of the pilot production or development tubing.

[0003] If the tubing becomes blocked by wax buildup, the conventional approach is to run in coiled tubing for mechanical unblocking, or to mechanically inject hot liquid into the coiled tubing on the ground to melt the wax and remove it from the surface. This type of dewaxing requires a huge amount of engineering equipment and manpower, resulting in high costs and requiring collaboration among multiple disciplines. Improper handling can easily cause environmental pollution on the ground. If the oil contains hydrogen sulfide, a leak could easily lead to serious incidents such as hydrogen sulfide poisoning. Summary of the Invention

[0004] The purpose of this invention is to provide a self-generating dewaxing device and method, which changes the traditional dewaxing and wax removal operation method. This invention utilizes the pressure difference between the oil nozzle and the downstream low-pressure area, and adds a self-generating device. The generating device and circuit are completely in a closed oxygen-deficient environment, and the controller automatically adjusts whether to generate electricity according to the temperature of the extracted fluid.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A self-generating dewaxing device, comprising an oil layer casing, annular protective fluid, oil and gas production tubing, electrical conductors, a pipeline control unit, a generator, and a wellhead output pipeline, wherein...

[0007] The oil and gas production tubing string includes an insulating layer, the oil and gas production tubing string is disposed inside the oil layer casing, and the annulus protection fluid is injected between the oil and gas production tubing string and the oil layer casing;

[0008] One end of the wellhead output pipeline is installed inside the oil and gas production tubing string, and the other end of the wellhead output pipeline is connected to the oil and gas receiving device and generator through the pipeline control unit.

[0009] One end of the conductor is connected to the annular protective fluid, and the other end of the conductor is connected to the generator.

[0010] Preferably, the pipeline control unit includes a first control valve, a controller, a second control valve, a normal pipeline, and a power generation pipeline, wherein...

[0011] The first end of the first control valve is connected to the wellhead output pipeline, the second end of the first control valve is connected to the air inlet of the generator through the generator pipeline, and the third end of the first control valve is connected to the first end of the second control valve through the normal pipeline.

[0012] The second end of the second control valve is connected to the exhaust port of the generator via the generator pipeline, and the third end of the second control valve is connected to the oil and gas receiving device.

[0013] The controller is used to control the switching of the first control valve and the second control valve.

[0014] Preferably, the insulating layer is disposed on the outer wall of the oil and gas tubing string, and the depth of the insulating layer is greater than the depth of the wax deposit.

[0015] Preferably, the annular protective fluid includes free cations;

[0016] The cation includes one or more of monovalent cations, divalent cations, or trivalent cations.

[0017] A self-generating dewaxing method, the method comprising the following steps:

[0018] When the wellhead temperature is higher than the first predetermined temperature, the oil and gas enter the oil and gas receiving device through the wellhead output pipeline and pipeline control unit.

[0019] When the wellhead temperature is lower than or equal to the first predetermined temperature, the oil and gas are generated by triggering the generator through the wellhead output pipeline and the pipeline control unit. The current generated by the generator is connected to the annular protective fluid and the oil and gas production tubing through the conductors to form a closed circuit, heating the oil and gas to above the critical temperature for wax precipitation.

[0020] When the generator generates electricity and heats the well to reach the second predetermined temperature, the oil and gas enter the oil and gas receiving device through the wellhead output pipeline and pipeline control unit.

[0021] One end of the wellhead output pipeline is located inside the oil and gas production tubing string, and the other end of the wellhead output pipeline is connected to the oil and gas receiving device and generator through the pipeline control unit.

[0022] The oil and gas tubing string is installed inside the oil layer casing, and the annulus protection fluid is injected between the oil and gas tubing string and the oil layer casing.

[0023] Preferably, the oil and gas entering the oil and gas receiving device via the wellhead output pipeline and pipeline control unit includes,

[0024] The controller in the pipeline control unit controls the second end of the first control valve to close and the first and third ends of the first control valve to open.

[0025] The controller controls the second end of the second control valve to close, and the first and third ends to open.

[0026] Preferably, the oil and gas enter the oil and gas receiving device via the wellhead output pipeline and the pipeline control unit, including the following steps:

[0027] When the wellhead temperature is higher than the first predetermined temperature, the oil and gas enter the oil and gas receiving device through the wellhead output pipeline, passing sequentially through the first and third ends of the first control valve, the normal pipeline, and the first and third ends of the second control valve.

[0028] Preferably, oil and gas are discharged through the wellhead pipeline and the pipeline control unit, triggering a generator to generate electricity, including:

[0029] When the wellhead temperature is lower than or equal to the first predetermined temperature, the controller adjusts the opening of the second end of the first control valve so that the oil and gas passing through the second end of the first control valve reaches the predetermined oil and gas flow rate. The controller then controls the first and third ends of the first control valve to open.

[0030] The controller adjusts the opening of the second end of the second control valve so that the oil and gas passing through the second end of the second control valve reaches the predetermined oil and gas flow rate. The controller controls the opening of the first and third ends of the second control valve.

[0031] Preferably, the oil and gas output pipeline and pipeline control unit triggering the generator to generate electricity includes:

[0032] The oil and gas enter the first end of the first control valve through the wellhead output pipeline, and the predetermined flow rate of oil and gas is discharged from the second end of the first control valve, enters the generator through the generator pipeline, and triggers the generator to generate electricity.

[0033] The remaining oil and gas are discharged from the third end of the first control valve and enter the oil and gas receiving device through the normal pipeline and the first and third ends of the second control valve.

[0034] Preferably, the oil and gas of the predetermined flow rate is discharged from the second end of the first control valve, enters the generator through the generator pipeline, and the oil and gas discharged through the generator exhaust port enters the second end of the second control valve through the generator pipeline, and is discharged from the third end of the second control valve into the oil and gas receiving device.

[0035] Preferably, the annular protective liquid includes free cations; the cations include one or more of monovalent cations, divalent cations, or trivalent cations.

[0036] Preferably, the first predetermined temperature is a wellhead temperature of 50-55℃; the second predetermined temperature is a downhole temperature of 60-75℃.

[0037] The technical effects and advantages of this invention are as follows:

[0038] This invention can control the operation of the generator at any time according to the ground temperature, realizing automatic dewaxing. It truly achieves efficient, safe, time-saving and high-quality dewaxing, completely avoiding a large investment in equipment and human resources. It has great practical value and is easy to promote.

[0039] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the self-generating dewaxing device of the present invention;

[0041] Figure 2 Schematic diagram of the downhole device in the self-generating dewaxing device of the present invention;

[0042] Figure 3 A schematic diagram of the control device in the self-generating dewaxing device of the present invention.

[0043] In the diagram, 1. Oil layer casing; 2. Annular protective fluid; 3. Oil and gas production tubing string; 4. Insulation layer; 5. Electrical conductor; 6. First control valve; 7. Controller; 8. Second control valve; 9. Normal pipeline; 10. Generator pipeline; 11. Generator; 12. Wellhead output pipeline. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] To address the shortcomings of existing technologies, this invention discloses a self-generating dewaxing device, such as... Figure 1 As shown, the device includes an oil layer casing 1, annular protection fluid 2, oil and gas production tubing string 3, electrical conductor 5, pipeline control unit, generator 11, and wellhead output pipeline 12. The oil layer casing 1 is used to protect the wellbore and establish a passage. The oil and gas production tubing string 3 is set inside the oil layer casing 1 and forms an annulus. The annular protection fluid 2 is injected into the annulus between the oil and gas production tubing string 3 and the oil layer casing 1.

[0046] Combination Figure 2The oil and gas production line 3 is used for oil and gas production, and an insulating layer 4 is applied to the outer side of the oil and gas production line 3 above the wax point. The depth of the insulating layer 4 is greater than the depth of the wax point. The insulating layer 4 is used to isolate the upper oil and gas production line 3 from the annulus protection fluid 2.

[0047] The annular protective liquid 2 includes free cations, and the addition of cations increases conductivity; the cations include one or more of monovalent, divalent, or trivalent cations, and exemplary examples include sodium ions, potassium ions, calcium ions, ammonium ions, iron ions, etc.

[0048] One end of the wellhead output pipeline 12 is installed inside the oil and gas production tubing string 3, and the other end of the wellhead output pipeline 12 is connected to the oil and gas receiving device and the generator 11 through the pipeline control unit; one end of the wire 5 is connected to the annulus protection fluid 2, and the other end of the wire 5 is connected to the generator 11.

[0049] Furthermore, such as Figure 3 As shown, the pipeline control unit includes a first control valve 6, a controller 7, a second control valve 8, a normal pipeline 9, and a power generation pipeline 10, wherein...

[0050] The controller 7 is used to adjust whether the first control valve 6 and the second control valve 8 are open or closed according to the changes in wellhead temperature, thereby controlling whether the generator 11 is working; the first control valve 6 and the second control valve 8 change the oil and gas passage by opening or closing the produced oil and gas; the normal pipeline 9 is used to close the second end of the first control valve 6 and the second control valve 8 when power generation is not required, and the oil and gas pass through the normal pipeline 9.

[0051] The generator line 10 is used to change the opening and closing of the first control valve 6 and the second control valve 8. Oil and gas can pass through the generator line 10 to make the generator 11 work and generate current.

[0052] The first end of the first control valve 6 is connected to the wellhead output pipeline 12, the second end of the first control valve 6 is connected to the air inlet of the generator 11 through the generator pipeline 10, and the third end of the first control valve 6 is connected to the first end of the second control valve 8 through the normal pipeline 9.

[0053] The second end of the second control valve 8 is connected to the exhaust port of the generator 11 through the generator pipeline 10, and the third end of the second control valve 8 is connected to the oil and gas receiving device.

[0054] The controller 7 is used to control whether the first control valve 6 and the second control valve 8 are opened or closed according to the change in wellhead temperature, thereby controlling whether the generator 11 works.

[0055] The generator 11 generates electricity by utilizing the pressure difference between the oil nozzle and the downstream low-pressure area.

[0056] The present invention also discloses a self-generating dewaxing method. In this method, an insulating layer 4 is coated on the outer layer of the oil and gas production tubing string 3, and a liquid containing metal ions is added to the annular protective fluid 2 in the oil and gas production tubing string 3 and the oil layer casing 1 to improve the conductivity of the annular protective fluid 2. According to the geothermal gradient, no insulating layer is coated on the outer wall of the oil production tubing string below the waxing point. In this way, the oil and gas production tubing string 3 and the annular protective fluid 2 form a closed-loop energized circuit.

[0057] After generator 11 starts working, it generates current, which heats up in the closed circuit formed in the oil and gas production tubing 3 and the annulus protective fluid 2, increasing the temperature of the annulus protective fluid 2 and the oil and gas production tubing 3, thus preventing further wax precipitation in the oil and gas. The controller can control the operation of generator 11 at any time according to the ground temperature, realizing automatic wax removal function. It truly achieves efficient, safe, time-saving, and high-quality wax removal, completely avoiding large-scale equipment and human resource investment, and has great practical value and is easy to promote.

[0058] A self-generating dewaxing method includes the following steps:

[0059] The depth h of the critical point for wax precipitation in oil and gas is determined based on the geothermal gradient and the temperature of the formation produced fluid. An insulating layer 4 is applied to the outer side of the oil and gas production string 3 above the wax deposition point. The depth of the insulating layer 4 is H, ensuring that H>h.

[0060] Annular protective fluid 2 is injected between the oil and gas tubing string 3 and the oil layer casing 1. Cationic liquid is added to the annular protective fluid 2 to improve conductivity.

[0061] When the wellhead temperature is higher than the first predetermined temperature, in one embodiment of the present invention, the first predetermined temperature is set to 50-55°C. At this time, the generator 11 does not need to generate electricity. The produced oil and gas enter the oil and gas receiving device through the wellhead output pipeline 12 and the pipeline control unit. At this time, the controller 7 in the pipeline control unit controls the second end of the first control valve 6 to close and the second end of the second control valve 8 to close, and controls the first end and the third end of the first control valve 6 to open and the first end and the third end of the second control valve 8 to open. The oil and gas directly enter the oil and gas receiving device through the first end and the third end of the first control valve 6, the normal pipeline 9, and the first end and the third end of the second control valve 8.

[0062] When the wellhead temperature is lower than or equal to a first predetermined temperature, in one embodiment of the present invention, the first predetermined temperature is set to 50-55°C. The controller 7 in the pipeline control unit adjusts the valve opening and closing states of the first control valve 6 and the second control valve 8. Oil and gas are output through the wellhead pipeline 12 and the pipeline control unit. Under the action of pressure difference and flow rate, the generator 11 is triggered to generate electricity. The current generated by the generator 11 is connected to the annular protective fluid 2 and the oil and gas production tubing 3 through the conductor 5 to form a closed circuit. According to Ohm's law, the well begins to heat up, heating the oil and gas. When the oil and gas are heated to above the critical temperature for wax precipitation, wax will not form.

[0063] Furthermore, the process of generating electricity by triggering the generator 11 via the wellhead output pipeline 12 and the pipeline control unit includes the following steps: the oil and gas enter the first end of the first control valve 6 via the wellhead output pipeline 12; a predetermined flow of oil and gas is discharged from the second end of the first control valve 6; the oil and gas then enters the generator 11 via the generator pipeline 10 and triggers the generator 11 to generate electricity; the remaining oil and gas is discharged from the third end of the first control valve 6; and the remaining oil and gas enters the oil and gas receiving device via the normal pipeline 9 and the first and third ends of the second control valve 8.

[0064] Furthermore, the predetermined flow rate of oil and gas is discharged from the second end of the first control valve 6, enters the generator 11 through the generator pipeline 10, and the oil and gas discharged from the exhaust port of the generator 11 enters the second end of the second control valve 8 through the generator pipeline 10, and is discharged from the third end of the second control valve 8 into the oil and gas receiving device.

[0065] If the generator 11 generates electricity and causes the downhole temperature to be too high, the controller 7 in the pipeline control unit sets a maximum temperature. Generally, the temperature setting is based on the wax deposition point temperature. In one embodiment of the present invention, the maximum temperature is set to 60-75°C. When the set maximum temperature is reached, the wax precipitation temperature will be reached. The controller 7 adjusts the valve opening and closing states of the first control valve 6 and the second control valve 8. The controller 7 controls the second end of the first control valve 6 to close and the second end of the second control valve 8 to close, and controls the first and third ends of the first control valve 6 and the second control valve 8 to open. Oil and gas directly enter the oil and gas receiving device through the first and third ends of the first control valve 6, the normal pipeline 9, and the first and third ends of the second control valve 8.

[0066] The self-generating dewaxing device and method of the present invention are simple to use, fully automated, and require no special dewaxing equipment or personnel intervention. They greatly improve the level of unattended automated oil and gas production, are safe, convenient, efficient, and easy to promote.

[0067] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-generating dewaxing device, characterized in that, The device includes an oil layer casing (1), annular protection fluid (2), oil and gas production tubing (3), electrical conductors (5), a pipeline control unit, a generator (11), and a wellhead output pipeline (12), wherein, The oil and gas production tubing string (3) includes an insulating layer (4), the oil and gas production tubing string (3) is disposed inside the oil layer casing (1), and the annulus protection fluid (2) is injected between the oil and gas production tubing string (3) and the oil layer casing (1); One end of the wellhead output pipeline (12) is located inside the oil and gas production string (3), and the other end of the wellhead output pipeline (12) is connected to the oil and gas receiving device and the generator (11) through the pipeline control unit. One end of the wire (5) is connected to the annular protective fluid (2), and the other end of the wire (5) is connected to the generator (11); The pipeline control unit includes a first control valve (6), a controller (7), a second control valve (8), a normal pipeline (9), and a power generation pipeline (10), wherein, The first end of the first control valve (6) is connected to the wellhead output pipeline (12), and the second end of the first control valve (6) is connected to the generator pipe. Line (10) is connected to the air inlet of generator (11), and the third end of the first control valve (6) is connected to the first end of the second control valve (8) through normal pipeline (9); The second end of the second control valve (8) is connected to the exhaust port of the generator (11) through the generator pipeline (10), and the third end of the second control valve (8) is connected to the oil and gas receiving device. The controller (7) is used to control the opening and closing of the first control valve (6) and the second control valve (8); The insulating layer (4) is disposed on the outer wall of the oil and gas pipeline string (3), and the depth of the insulating layer (4) is greater than the depth of the wax point; The annular protective liquid (2) contains free cations; The cation includes one or more of monovalent cations, divalent cations, or trivalent cations.

2. A self-generating dewaxing method, characterized in that, The method using the self-generating dewaxing device according to claim 1 includes the following steps: When the wellhead temperature is higher than the first predetermined temperature, the oil and gas enter the oil and gas receiving device through the wellhead output pipeline (12) and the pipeline control unit; When the wellhead temperature is lower than or equal to the first predetermined temperature, the oil and gas are generated by triggering the generator (11) through the wellhead output pipeline (12) and the pipeline control unit. The current generated by the generator (11) is connected to the annular protective fluid (2) and the oil and gas production tubing (3) through the wire (5) to form a closed circuit, heating the oil and gas to above the critical temperature for wax precipitation. When the generator (11) generates electricity and heats the well to reach the second predetermined temperature, the oil and gas enter the oil and gas receiving device through the wellhead output pipeline (12) and the pipeline control unit. One end of the wellhead output pipeline (12) is located inside the oil and gas production string (3), and the other end of the wellhead output pipeline (12) is connected to the oil and gas receiving device and the generator (11) through the pipeline control unit. The oil and gas production tubing string (3) is installed inside the oil layer casing (1), and the annulus protection fluid (2) is injected between the oil and gas production tubing string (3) and the oil layer casing (1).

3. The self-generating dewaxing method according to claim 2, characterized in that, The oil and gas enter the oil and gas receiving device via the wellhead output pipeline (12) and the pipeline control unit, including: The controller (7) in the pipeline control unit controls the second end of the first control valve (6) to close and the first and third ends of the first control valve (6) to open; The controller (7) controls the second end of the second control valve (8) to close and the first and third ends to open.

4. A self-generating dewaxing method according to claim 2 or 3, characterized in that, The oil and gas enter the oil and gas receiving device through the wellhead output pipeline (12) and the pipeline control unit, including the following steps: When the wellhead temperature is higher than the first predetermined temperature, the oil and gas enter the oil and gas receiving device through the wellhead output pipeline (12), the first and third ends of the first control valve (6), the normal pipeline (9), and the first and third ends of the second control valve (8).

5. The self-generating dewaxing method according to claim 2, characterized in that, Oil and gas are generated by triggering a generator (11) via the wellhead output pipeline (12) and the pipeline control unit, including... When the wellhead temperature is lower than or equal to the first predetermined temperature, the controller (7) adjusts the opening of the second end of the first control valve (6) so that the oil and gas passing through the second end of the first control valve (6) reaches the predetermined oil and gas flow rate. The controller (7) controls the first end and the third end of the first control valve (6) to open. The controller (7) adjusts the opening of the second end of the second control valve (8) so that the oil and gas passing through the second end of the second control valve (8) reaches the predetermined oil and gas flow rate. The controller (7) controls the first and third ends of the second control valve (8) to open.

6. A self-generating dewaxing method according to claim 2 or 5, characterized in that, The oil and gas output pipeline (12) and pipeline control unit trigger the generator (11) to generate electricity, including: The oil and gas enter the first end of the first control valve (6) through the wellhead output pipeline (12), and the predetermined flow rate of oil and gas is discharged from the second end of the first control valve (6), enters the generator (11) through the power generation pipeline (10), and triggers the generator (11) to generate electricity. The remaining oil and gas are discharged from the third end of the first control valve (6), and enter the oil and gas receiving device through the normal pipeline (9) and the first and third ends of the second control valve (8).

7. The self-generating dewaxing method according to claim 6, characterized in that, The predetermined flow rate of oil and gas is discharged from the second end of the first control valve (6), enters the generator (11) through the generator pipeline (10), and the oil and gas discharged from the exhaust port of the generator (11) enters the second end of the second control valve (8) through the generator pipeline (10), and is discharged from the third end of the second control valve (8) into the oil and gas receiving device.

8. The self-generating dewaxing method according to claim 2, characterized in that, The annular protective liquid (2) includes free cations; the cations include one or more of monovalent cations, divalent cations, or trivalent cations.

9. The self-generating dewaxing method according to claim 2, characterized in that, The first predetermined temperature is a wellhead temperature of 50-55℃; the second predetermined temperature is a downhole temperature of 60-75℃.

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