Device and method for supercritical extraction of mineral oil using oil-based drilling fluid

Abstract

The present invention discloses a device and method for supercritical extraction of mineral oil by oil-based drilling fluid. The device comprises a CO2 storage component, a mineral oil extraction component and a separation component which are connected in sequence; a CO2 storage tank of the CO2 storage component and a pressure pump connected to the CO2 storage tank; the mineral oil extraction component comprises an extraction tank with a porous partition provided inside, a hot water jacket sleeved on the outside of the extraction tank, a driving motor provided on the top of the extraction tank and a mixing component provided inside the extraction tank; the mixing component comprises a first shaft connected to the driving motor, a second shaft clamped with the first shaft, a first stirrer sleeved on the first shaft and a second stirrer sleeved on the second shaft; the separation component comprises a separation tank and a filter disc provided inside the separation tank. The present invention has a reasonable structural design, high oil-based drilling fluid extraction efficiency and is suitable for popularization and use.

Description

Technical Field

[0001] The present invention relates to the technical field of supercritical extraction of drilling fluid, and in particular to a device and a method for supercritical extraction of mineral oil by oil-based drilling fluid. Background Art

[0002] my country's oil and gas resource development has now entered the mid-to-late-stage. With the continuous advancement of oil and gas exploration and development, drilling and development are increasingly moving into deeper and more complex formations, placing higher demands on drilling fluid technology. Oil-based drilling fluid is a sol-suspension mixed system composed of a base oil as the dispersion medium and additives such as organic soil, emulsifiers, stabilizers, and fluid loss reducers. Compared with water-based drilling fluids, oil-based drilling fluids offer superior lubricity, inhibition, and thermal stability, and are less damaging to oil and gas reservoirs. Oil-based drilling fluids are generally recycled, but their performance deteriorates with increasing use. Furthermore, as drill cuttings continue to infiltrate during drilling, the amount of oil-wetted solids in the fluid increases. Oil-wetted solids lack an electrical charge, making them difficult to flocculate and deposit for removal. Old oil-based slurry returned to the drilling fluid station from the field is typically centrifuged to remove as much undesirable solids as possible. It is then diluted proportionally with new slurry or a base oil such as white oil for reuse.

[0003] However, conventional centrifugation is not effective in removing such solid phases. The accumulation of oil-wet solid phases will affect the stability of the drilling fluid, eventually causing the performance of the oil-based drilling fluid to deteriorate and become unusable. The waste oil-based drilling fluid must be treated harmlessly, which undoubtedly increases the cost of using and treating the drilling fluid. Summary of the Invention

[0004] In response to the above-mentioned technical problems, the present invention provides a device for supercritical extraction of mineral oil using oil-based drilling fluid.

[0005] The technical solution of the present invention is: a device for supercritical extraction of mineral oil from oil-based drilling fluid, comprising a CO2 storage component, a mineral oil extraction component connected to the CO2 storage component via a first Y-shaped conduit, and a separation component connected to the mineral oil extraction component via an output pipe;

[0006] The CO2 storage component, mineral oil extraction component, and separation component are all arranged on the base. The CO2 storage component includes a CO2 storage tank with an air inlet pipe on the top and an electric heating coil inside, and a pressure pump connected to the CO2 storage tank; a proportional regulating valve is arranged on the first Y-shaped conduit, and a control valve is arranged on the output pipe;

[0007] The mineral oil extraction assembly includes an extraction tank having a porous partition at an upper position inside, a movable cover clamped on the top, and a liquid outlet pipe at a lower position of the side wall; a heating water jacket sleeved on the outside of the extraction tank and having a water inlet pipe and a water outlet pipe respectively provided at the upper and lower ends of the side wall; a driving motor disposed on the top of the movable cover; and a mixing member disposed inside the extraction tank and connected to the driving motor; two ports of a first Y-shaped conduit respectively pass through the heating water jacket and are respectively connected to the upper and lower ends of the extraction tank; the movable cover is connected to the extraction tank by bolts, and the movable cover is provided with a liquid inlet pipe; the mixing member includes a first shaft rod vertically passing through the movable cover and connected to the output end of the driving motor; a second shaft rod rotatably clamped to the porous partition and the bottom of the extraction tank respectively and clamped to the first shaft rod via a connector; a first agitator sleeved on the first shaft rod; and a second agitator sleeved on the second shaft rod;

[0008] The separation assembly includes a separation tank with an air outlet pipe on the top, a pressure relief valve on the upper side wall, an oil outlet pipe on the lower side wall, and several filter discs equidistantly arranged inside the separation tank.

[0009] Furthermore, the first agitator includes a connecting sleeve sleeved on the first shaft and having a plurality of hollow tubes scattered around the circumference, a mixing rod rotatably clamped on the hollow tubes and having a stirring wheel sleeved on the outside, a bevel gear provided on the end away from the first shaft, and a gear ring clamped inside the extraction tank and meshing with the bevel gear;

[0010] Description: During use, the drive motor drives the first shaft to rotate. The first shaft drives the connecting sleeve and the hollow tube to rotate simultaneously. As a result, the mixing rod rotates with the hollow tube, and the meshing action of the bevel gear and the ring gear causes the mixing rod to rotate on its own. The stirring wheel continuously stirs the drilling cuttings, making the mixing of the drilling cuttings and supercritical CO2 more uniform, thereby improving the extraction efficiency of the oil in the drilling cuttings.

[0011] Furthermore, two first agitators are provided, and the two first agitators are arranged side by side in an upper and lower manner inside the extraction tank. An air inlet groove is provided on the inner wall of the extraction tank at positions corresponding to the positions of the two first agitators. A second Y-shaped conduit is provided on the outer wall of the extraction tank, which is respectively connected to the two air inlet grooves and connected to the first Y-shaped conduit. The end of each hollow tube is connected to the air inlet groove at the corresponding position, and each stirring wheel is provided with a spray head connected to the interior of the hollow tube at the corresponding position.

[0012] Note: The supercritical CO2 is introduced into each hollow tube using the second Y-shaped conduit and sprayed into the drilling debris through the injection head on the stirring wheel, which is beneficial to improving the mixing efficiency of the supercritical CO2 and the drilling debris.

[0013] Furthermore, two sealing sleeves are provided inside the extraction tank and are respectively sleeved on the outside of the two gear rings. A rotating sleeve is slidably engaged with the sealing sleeve, and each hollow tube is rotatably engaged with the rotating sleeve at the corresponding position.

[0014] Note: The provision of a sealing sleeve and a rotating sleeve can prevent drilling debris from entering the sealing sleeve, thereby ensuring the stability of the meshing effect between the bevel gear and the ring gear.

[0015] Furthermore, the second agitator includes an extrusion plate threadedly connected to the second shaft and slidably engaged with the inner wall of the extraction tank, and a plurality of liquid guide tubes vertically penetrating the extrusion plate and having a liquid spraying seat rotatably engaged at the top;

[0016] Description: When the second shaft rotates, the extrusion plate slides up and down along the inner wall of the extraction tank, so that the mixture of drilling waste fluid and supercritical CO2 enters the liquid guide tube under the squeezing action of the extrusion plate, and falls back into the extraction tank through the liquid spray seat, which is beneficial to improve the mixing effect of drilling waste fluid and supercritical CO2.

[0017] Furthermore, the lower surface of the extrusion plate and the bottom of the extraction tank are rotatably engaged with mounting sleeves corresponding to the upper and lower positions, and the second shaft is slidably engaged with a positioning sleeve with a plurality of sliding rods arranged circumferentially, each sliding rod is provided with a sliding sleeve, and each sliding sleeve has stirring rods movably hinged at the upper and lower ends, and each stirring rod has an end away from the sliding sleeve and a mounting sleeve at a corresponding position.

[0018] Description: When the second shaft rotates, it drives the positioning sleeve to rotate, and the sliding rod drives the stirring rod and the mounting sleeve to rotate; at the same time, when the extrusion plate moves up and down, the angle between the two stirring rods on the same sliding sleeve changes continuously, thereby making the drilling waste fluid and supercritical CO2 mix more evenly and improving the extraction effect of oil in the drilling waste fluid.

[0019] Furthermore, a cleaning motor is provided on the top of the separation tank, and the output shaft passes through the separation tank and each filter disc in sequence and then rotates and engages with the bottom of the separation tank. A cleaning scraper is sleeved on the output shaft and abuts against the bottom surface of each filter disc.

[0020] Note: The oil carried in the CO2 gas is blocked by the filter disc and gathered at the lower end of the filter disc. Using a cleaning scraper to clean the oil at the lower end of the filter disc can avoid clogging of the filter disc and improve the separation effect of CO2 gas and oil.

[0021] Furthermore, a lifting lug is provided on the movable cover, and a sealing ring is provided at the connection between the movable cover and the extraction tank;

[0022] Note: The provision of the lifting lug facilitates separation of the movable cover and the extraction tank, and the provision of the sealing ring helps to improve the air tightness of the extraction tank, thereby improving the extraction effect of the extraction tank.

[0023] Furthermore, it also includes a PLC controller, the proportional control valve, the control valve, and the pressure relief valve are all electrically controlled valves, and the PLC controller is electrically connected to the proportional control valve, the control valve, the pressure relief valve, the electric heating coil, the pressure pump, and the drive motor respectively;

[0024] Note: Setting up a PLC controller is beneficial to improving the working efficiency and operational safety of the present invention.

[0025] The present invention also provides a method for supercritical extraction of mineral oil using oil-based drilling fluid, comprising the following steps:

[0026] S1. Connect the proportional control valve, control valve, pressure relief valve, electric heating coil, pressure pump and drive motor to the external power supply respectively;

[0027] S2. Inject CO2 gas into the CO2 storage tank through the air inlet pipe on the CO2 storage tank, and turn on the electric heating coil and the pressure pump to convert the CO2 gas into a supercritical state;

[0028] S3. Injecting oil-based drilling fluid into the extraction tank through the liquid inlet pipe on the extraction tank. Drilling debris in the oil-based drilling fluid is blocked by the porous partition and flows to the upper part of the extraction tank. Drilling waste fluid passes through the porous partition and flows into the lower part of the extraction tank. Simultaneously, hot water is injected into the heating water jacket through the water inlet pipe on the heating water jacket and circulated through the water outlet pipe to heat the drilling debris and drilling waste fluid.

[0029] S4. Opening the proportional regulating valve and the driving motor allows the supercritical CO2 to enter the two ends of the extraction tank in proportion through the first Y-shaped conduit, respectively, and come into contact with the drilling cuttings and the drilling waste fluid, respectively; the driving motor drives the first shaft and the second shaft to rotate respectively; the rotation of the first shaft drives the first stirrer to rotate, so that the supercritical CO2 fully contacts the drilling cuttings; the rotation of the second shaft drives the second stirrer to rotate, so that the supercritical CO2 fully contacts the drilling waste fluid; and the supercritical CO2 extracts the oil phase of the drilling cuttings and the drilling waste fluid;

[0030] S5. Open the control valve to allow the supercritical CO2 and oil phase mixture to enter the separation tank through the output pipe; then open the pressure relief valve to reduce the pressure of the supercritical CO2 and convert it into gaseous CO2, which is discharged and collected through the outlet pipe. When the CO2 gas rises inside the separation tank, the filter disc is used to filter the oil mixed in the CO2 gas; the oil is discharged from the separation tank through the oil outlet pipe for collection;

[0031] S6. Open the movable cover on the top of the extraction tank, clean the drilling debris blocked by the porous partition, and discharge the drilling waste liquid from which the oil is extracted into the extraction tank through the liquid outlet pipe.

[0032] Compared with the prior art, the beneficial effects of the present invention are embodied in the following aspects:

[0033] First, the device of the present invention has a reasonable structural design. By filtering the drilling debris in the oil-based drilling fluid and using supercritical CO2 to extract the oil phase in the drilling fluid and the drilling debris in steps, it can not only improve the extraction effect of the oil-based drilling fluid, but also prevent the drilling debris from entering the downstream equipment and causing damage to the equipment, and has high stability and reliability.

[0034] Second, the first and second agitators designed in the present invention can fully contact and mix the supercritical CO2 with the drilling waste fluid and drilling cuttings, so that the oil phase in the drilling waste fluid and drilling cuttings can be fully removed, which not only improves the yield of mineral oil but also effectively solves the environmental pollution problem caused by the indiscriminate discharge of drilling waste fluid and drilling cuttings.

[0035] Third, the device of the present invention has high integration and is easy to operate, which promotes the development of the oil drilling industry and improves economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a longitudinal sectional view of the present invention;

[0037] Figure 2 It is a front view of the present invention;

[0038] Figure 3 is a schematic diagram of the connection between the first agitator and the extraction tank of the present invention;

[0039] Figure 4 Schematic diagram of the connection between the mixing rod and the sealing sleeve of the present invention;

[0040] Figure 5 It is a schematic structural diagram of the stirring wheel of the present invention;

[0041] Figure 6 This invention Figure 1 A partial enlarged schematic diagram of point A in the middle;

[0042] Figure 7 is a distribution diagram of the liquid guide tubes of the present invention on the extrusion disk;

[0043] Figure 8 This is a schematic diagram of the connection between the stirring rod and the mounting sleeve of the present invention;

[0044] Figure 9 This is a schematic diagram of the connection between the cleaning scraper and the filter disc of the present invention;

[0045] Among them, 1-CO2 storage component, 10-first Y-shaped conduit, 100-proportional regulating valve, 11-CO2 storage tank, 110-air inlet pipe, 12-electric heating coil, 13-pressurization pump, 2-mineral oil extraction component, 20-output pipe, 200-control valve, 21-extraction tank, 210-porous partition, 211-movable cover, 212-liquid outlet pipe, 213-liquid inlet pipe, 214-air inlet groove, 215-second Y-shaped conduit, 22-heating water jacket, 220-water inlet pipe, 221-water outlet pipe, 23-drive motor, 24-mixing component, 240-first shaft, 241-second shaft, 2410-connector, 2 5-first agitator, 250-hollow tube, 251-connecting sleeve, 252-stirring wheel, 2520-injection head, 253-bevel gear, 254-mixing rod, 255-ring gear, 26-second agitator, 260-extrusion plate, 261-liquid guide tube, 2610-spray seat, 262-mounting sleeve, 263-sliding rod, 2630-sliding sleeve, 264-locking sleeve, 265-stirring rod, 27-sealing sleeve, 270-rotating sleeve, 3-separation assembly, 30-separation tank, 300-air outlet pipe, 301-pressure relief valve, 302-oil outlet pipe, 31-filter disc, 32-cleaning motor, 33-cleaning scraper, 4-base. DETAILED DESCRIPTION

[0046] Example 1

[0047] like Figure 1 The device for supercritical extraction of mineral oil from oil-based drilling fluid shown in the figure includes a CO2 storage assembly 1, a mineral oil extraction assembly 2 connected to the CO2 storage assembly 1 via a first Y-shaped conduit 10, and a separation assembly 3 connected to the mineral oil extraction assembly 2 via an output pipe 20. The CO2 storage assembly 1, the mineral oil extraction assembly 2, and the separation assembly 3 are all disposed on a base 4. The CO2 storage assembly 1 includes a CO2 storage tank 11 with an air inlet pipe 110 disposed on the top and an electric heating coil 12 disposed therein, and a pressure pump 13 connected to the CO2 storage tank 11. A proportional regulating valve 100 is disposed on the first Y-shaped conduit 10, and a control valve 200 is disposed on the output pipe 20.

[0048] like Figure 1 、 2As shown, the mineral oil extraction assembly 2 includes an extraction tank 21 with a porous partition 210 at the upper position inside, a movable cover 211 clamped on the top, and a liquid outlet pipe 212 at the lower position of the side wall, a heating water jacket 22 set on the outside of the extraction tank 21 and with a water inlet pipe 220 and a water outlet pipe 221 at the upper and lower ends of the side wall respectively, a driving motor 23 set on the top of the movable cover 211 and a mixing member 24 set inside the extraction tank 21 and connected to the driving motor 23; two ports of the first Y-shaped conduit 10 respectively penetrate the heating water jacket 22 and respectively The movable cover 211 is connected to the extraction tank 21 via bolts at both ends of the extraction tank 21. A liquid inlet pipe 213 is provided on the movable cover 211. The mixing member 24 includes a first shaft 240 that vertically passes through the movable cover 211 and is connected to the output end of the drive motor 23; a second shaft 241 that is rotatably engaged with the porous partition 210 and the bottom of the extraction tank 21, respectively, and is engaged with the first shaft 240 via a connector 2410; a first agitator 25 sleeved on the first shaft 240; and a second agitator 26 sleeved on the second shaft 241.

[0049] like Figure 1 As shown, the separation assembly 3 includes a separation tank 30 with an air outlet pipe 300 on the top, a pressure relief valve 301 on the upper side wall, an oil outlet pipe 302 on the lower side wall, and two filter discs 31 equidistantly arranged inside the separation tank 30.

[0050] Example 2

[0051] This embodiment describes a method for supercritical extraction of mineral oil from oil-based drilling fluid using the apparatus of Example 1, comprising the following steps:

[0052] S1. Connect the proportional control valve 100, the control valve 200, the pressure relief valve 301, the electric heating coil 12, the pressure pump 13 and the drive motor 23 to an external power source respectively;

[0053] S2. Inject CO2 gas into the CO2 storage tank 11 through the air inlet pipe 110 on the CO2 storage tank 11, and turn on the electric heating coil 12 and the pressure pump 13 to convert the CO2 gas into a supercritical state;

[0054] S3. Injecting oil-based drilling fluid into the extraction tank 21 through the liquid inlet pipe 213 on the extraction tank 21. Drilling debris in the oil-based drilling fluid is blocked by the porous partition 210 and flows to the upper part of the extraction tank 21. Drilling waste fluid passes through the porous partition 210 and enters the lower part of the extraction tank 21. Simultaneously, hot water is injected into the heating water jacket 22 through the water inlet pipe 220 on the heating water jacket 22 and circulated through the water outlet pipe 221 to heat the drilling debris and drilling waste fluid.

[0055] S4. Open the proportional regulating valve 100 and the drive motor 23, allowing the supercritical CO2 to enter the two ends of the extraction tank 21 in proportion through the first Y-shaped conduit 10, respectively, and come into contact with the drilling cuttings and the drilling waste fluid. The drive motor 23 drives the first shaft 240 and the second shaft 241 to rotate respectively. The rotation of the first shaft 240 drives the first stirrer 25 to rotate, so that the supercritical CO2 fully contacts the drilling cuttings. The rotation of the second shaft 241 drives the second stirrer 26 to rotate, so that the supercritical CO2 fully contacts the drilling waste fluid. The supercritical CO2 extracts the oil phase of the drilling cuttings and the drilling waste fluid.

[0056] S5. Open the control valve 200 to allow the supercritical CO2 and oil phase mixture to enter the separation tank 30 through the output pipe 20; then open the pressure relief valve 301. After the supercritical CO2 pressure is reduced, it is converted into gaseous CO2 and discharged through the outlet pipe 300 for collection. As the CO2 gas rises inside the separation tank 30, the filter disc 31 is used to filter the oil mixed in the CO2 gas; the oil is discharged from the separation tank 30 through the oil outlet pipe 302 for collection;

[0057] S6. Open the movable cover 211 on the top of the extraction tank 21, clean the drilling debris blocked by the porous partition 210, and discharge the drilling waste liquid from which the oil is extracted from the extraction tank 21 through the liquid outlet pipe 212.

[0058] Example 3

[0059] like Figure 1 The device for supercritical extraction of mineral oil from oil-based drilling fluid shown in the figure includes a CO2 storage assembly 1, a mineral oil extraction assembly 2 connected to the CO2 storage assembly 1 via a first Y-shaped conduit 10, and a separation assembly 3 connected to the mineral oil extraction assembly 2 via an output pipe 20. The CO2 storage assembly 1, the mineral oil extraction assembly 2, and the separation assembly 3 are all disposed on a base 4. The CO2 storage assembly 1 includes a CO2 storage tank 11 with an air inlet pipe 110 disposed on the top and an electric heating coil 12 disposed therein, and a pressure pump 13 connected to the CO2 storage tank 11. A proportional regulating valve 100 is disposed on the first Y-shaped conduit 10, and a control valve 200 is disposed on the output pipe 20.

[0060] like Figure 1 、 2As shown in Figures 3, 5, 6 and 7, the mineral oil extraction assembly 2 includes an extraction tank 21 with a porous partition 210 at the upper position inside, a movable cover 211 clamped on the top, a liquid outlet pipe 212 at the lower position of the side wall, a heating water jacket 22 set on the outside of the extraction tank 21, and a water inlet pipe 220 and a water outlet pipe 221 at the upper and lower ends of the side wall respectively, a driving motor 23 set on the top of the movable cover 211 and a mixing member 24 set inside the extraction tank 21 and connected to the driving motor 23; two ports of the first Y-shaped conduit 10 respectively penetrate the heating water jacket 22 and are respectively connected to the extraction tank 21. The upper and lower ends of the extraction tank 21 are connected, and the movable cover 211 is connected to the extraction tank 21 by bolts. The movable cover 211 is provided with a liquid inlet pipe 213; the mixing member 24 includes a first shaft 240 that vertically passes through the movable cover 211 and is connected to the output end of the drive motor 23, a second shaft 241 that is rotatably connected to the porous partition 210 and the bottom of the extraction tank 21 and is connected to the first shaft 240 through a connector 2410, a first agitator 25 sleeved on the first shaft 240, and a second agitator 26 sleeved on the second shaft 241; the first agitator 25 includes a first agitator sleeved on the second shaft 240 and a second agitator 26 sleeved on the second shaft 241; A connecting sleeve 251 with four hollow tubes 250 is arranged on a shaft 240 and is scattered in the circumferential direction; a mixing rod 254 is rotatably connected to the hollow tube 250 and is provided with a stirring wheel 252 on the outside; a mixing rod 254 is provided with a bevel gear 253 at the end away from the first shaft 240; and a gear ring 255 is connected to the inside of the extraction tank 21 and is meshed with the bevel gear 253; two first agitators 25 are provided, and the two first agitators 25 are arranged in parallel inside the extraction tank 21. An air inlet groove 214 is provided on the inner wall of the extraction tank 21 at the positions corresponding to the two first agitators 25. 1 is provided on the outer wall thereof with a second Y-shaped conduit 215, which is in communication with the two air inlet grooves 214 and connected to the first Y-shaped conduit 10. The ends of each hollow tube 250 are in communication with the air inlet grooves 214 at the corresponding position. Each stirring wheel 252 is provided with a spray head 2520, which is in communication with the interior of the corresponding hollow tube 250. The second stirrer 26 includes an extrusion plate 260, which is threadedly connected to the second shaft 241 and slidably engaged with the inner wall of the extraction tank 21, and twelve liquid guide tubes 261, which are vertically provided through the extrusion plate 260 and have a liquid spray seat 2610 rotatably engaged at the top.

[0061] like Figure 1 As shown, the separation assembly 3 includes a separation tank 30 with an air outlet pipe 300 on the top, a pressure relief valve 301 on the upper side wall, an oil outlet pipe 302 on the lower side wall, and two filter discs 31 equidistantly arranged inside the separation tank 30.

[0062] Example 4

[0063] This embodiment describes a method for supercritical extraction of mineral oil from oil-based drilling fluid using the apparatus of Example 3, comprising the following steps:

[0064] S1. Connect the proportional control valve 100, the control valve 200, the pressure relief valve 301, the electric heating coil 12, the pressure pump 13 and the drive motor 23 to an external power source respectively;

[0065] S2. Inject CO2 gas into the CO2 storage tank 11 through the air inlet pipe 110 on the CO2 storage tank 11, and turn on the electric heating coil 12 and the pressure pump 13 to convert the CO2 gas into a supercritical state;

[0066] S3. Injecting oil-based drilling fluid into the extraction tank 21 through the liquid inlet pipe 213 on the extraction tank 21. Drilling debris in the oil-based drilling fluid is blocked by the porous partition 210 and flows to the upper part of the extraction tank 21. Drilling waste fluid passes through the porous partition 210 and enters the lower part of the extraction tank 21. Simultaneously, hot water is injected into the heating water jacket 22 through the water inlet pipe 220 on the heating water jacket 22 and circulated through the water outlet pipe 221 to heat the drilling debris and drilling waste fluid.

[0067] S4, open the proportional regulating valve 100 and the driving motor 23, so that the supercritical CO2 enters the two ends of the extraction tank 21 in proportion through the first Y-shaped conduit 10, and contacts the drilling debris and the drilling waste liquid respectively; the driving motor 23 drives the first shaft 240 and the second shaft 241 to rotate respectively, and the first shaft 240 drives the connecting sleeve 251 and the hollow tube 250 to rotate simultaneously, so that when the mixing rod 254 rotates with the hollow tube 250, it rotates under the meshing action of the bevel gear 253 and the ring gear 255, and the drilling debris is continuously stirred by the stirring wheel 252, and the drilling debris is continuously stirred by the first shaft 240. The two Y-shaped conduits 215 direct supercritical CO2 into the interior of each hollow tube 250 and spray it into the drilling debris through the spray head 2520 on the stirring wheel 252, ensuring full contact between the supercritical CO2 and the drilling debris. As the second shaft 241 rotates, the extrusion plate 260 slides up and down along the inner wall of the extraction tank 21, forcing the mixture of drilling waste fluid and supercritical CO2 into the liquid guide tube 261 under the extrusion action of the extrusion plate 260. The mixture then falls back into the extraction tank 21 through the liquid spray seat 2610, allowing the supercritical CO2 to extract the oil phase from the drilling debris and drilling waste fluid.

[0068] S5. Open the control valve 200 to allow the supercritical CO2 and oil phase mixture to enter the separation tank 30 through the output pipe 20; then open the pressure relief valve 301. After the supercritical CO2 pressure is reduced, it is converted into gaseous CO2 and discharged through the outlet pipe 300 for collection. As the CO2 gas rises inside the separation tank 30, the filter disc 31 is used to filter the oil mixed in the CO2 gas; the oil is discharged from the separation tank 30 through the oil outlet pipe 302 for collection;

[0069] S6. Open the movable cover 211 on the top of the extraction tank 21, clean the drilling debris blocked by the porous partition 210, and discharge the drilling waste liquid from which the oil is extracted from the extraction tank 21 through the liquid outlet pipe 212.

[0070] Example 5

[0071] like Figure 1 The device for supercritical extraction of mineral oil from oil-based drilling fluid shown in the figure includes a CO2 storage assembly 1, a mineral oil extraction assembly 2 connected to the CO2 storage assembly 1 via a first Y-shaped conduit 10, a separation assembly 3 connected to the mineral oil extraction assembly 2 via an output pipe 20, and a PLC controller. The CO2 storage assembly 1, the mineral oil extraction assembly 2, and the separation assembly 3 are all disposed on a base 4. The CO2 storage assembly 1 includes a CO2 storage tank 11 with an air inlet pipe 110 disposed on the top and an electric heating coil 12 disposed therein, and a pressure pump 13 connected to the CO2 storage tank 11. A proportional regulating valve 100 is disposed on the first Y-shaped conduit 10, and a control valve 200 is disposed on the output pipe 20.

[0072] like Figure 1 、 2As shown in Figures 3, 5, 6, 7 and 8, the mineral oil extraction assembly 2 includes an extraction tank 21 with a porous partition 210 at the upper position inside, a movable cover 211 clamped on the top, a liquid outlet pipe 212 at the lower position of the side wall, a heating water jacket 22 set on the outside of the extraction tank 21 and provided with a water inlet pipe 220 and a water outlet pipe 221 at the upper and lower ends of the side wall respectively, a driving motor 23 set on the top of the movable cover 211 and a mixing member 24 set inside the extraction tank 21 and connected to the driving motor 23; two ports of the first Y-shaped conduit 10 respectively penetrate the heating water jacket 22 and are respectively connected to the upper and lower ends of the extraction tank 21, the movable cover 211 is connected to the extraction tank 21 by bolts, and the movable cover 211 is connected to the extraction tank 21 by bolts. A liquid inlet pipe 213 is provided on the top; the mixing member 24 includes a first shaft 240 that vertically passes through the movable cover 211 and is connected to the output end of the drive motor 23, a second shaft 241 that is rotatably connected to the porous partition 210 and the bottom of the extraction tank 21 and is connected to the first shaft 240 through a connector 2410, a first agitator 25 sleeved on the first shaft 240, and a second agitator 26 sleeved on the second shaft 241; the first agitator 25 includes a connecting sleeve 251 sleeved on the first shaft 240 and having four hollow tubes 250 distributed in a circumferential manner, a stirring wheel 252 that is rotatably connected to the hollow tube 250 and is sleeved on the outside, and a bevel gear is provided at the end away from the first shaft 240. 253 of the mixing rod 254 and the ring gear 255 that is clamped inside the extraction tank 21 and meshed with the bevel gear 253; there are two first agitators 25, which are arranged in parallel inside the extraction tank 21. The inner wall of the extraction tank 21 is provided with air inlet grooves 214 at positions corresponding to the positions of the two first agitators 25. The outer wall of the extraction tank 21 is provided with a second Y-shaped conduit 215 that is respectively connected to the two air inlet grooves 214 and connected to the first Y-shaped conduit 10. The ends of each hollow tube 250 are connected to the air inlet grooves 214 at the corresponding positions, and each stirring wheel 252 is provided with a spray head 2520 that is connected to the inside of the hollow tube 250 at the corresponding position; the second agitator 25 6 includes an extrusion plate 260 threadedly connected to the second shaft 241 and slidably engaged with the inner wall of the extraction tank 21; 12 liquid guide tubes 261 vertically extending through the extrusion plate 260 and having a liquid spray seat 2610 rotatably engaged at the top; mounting sleeves 262 corresponding to upper and lower positions are rotatably engaged on the lower bottom surface of the extrusion plate 260 and the inner bottom of the extraction tank 21; a retaining sleeve 264 slidably engaged with six sliding rods 263 circumferentially arranged on the second shaft 241, each sliding rod 263 being provided with a sliding sleeve 2630, and each sliding sleeve 2630 having a stirring rod 265 movably hinged at its upper and lower ends, and each stirring rod 265 having an end away from the sliding sleeve 2630 movably hinged to a mounting sleeve 262 at a corresponding position;

[0073] like Figure 1As shown, the separation assembly 3 includes a separation tank 30 with an air outlet pipe 300 on the top, a pressure relief valve 301 on the upper side wall, an oil outlet pipe 302 on the lower side wall, and two filter discs 31 equidistantly arranged inside the separation tank 30; the proportional regulating valve 100, the control valve 200, and the pressure relief valve 301 are all electrically controlled valves;

[0074] The PLC controller is electrically connected to the proportional regulating valve 100 , the control valve 200 , the pressure relief valve 301 , the electric heating coil 12 , the pressure pump 13 and the driving motor 23 , respectively.

[0075] Example 6

[0076] This embodiment describes a method for supercritical extraction of mineral oil from oil-based drilling fluid using the apparatus of Example 5, comprising the following steps:

[0077] S1. Connect the proportional control valve 100, the control valve 200, the pressure relief valve 301, the electric heating coil 12, the pressure pump 13 and the drive motor 23 to an external power source respectively;

[0078] S2. Inject CO2 gas into the CO2 storage tank 11 through the air inlet pipe 110 on the CO2 storage tank 11, and use the PLC controller to control the electric heating coil 12 and the pressure pump 13 to turn on, so that the CO2 gas is converted to a supercritical state;

[0079] S3. Injecting oil-based drilling fluid into the extraction tank 21 through the liquid inlet pipe 213 on the extraction tank 21. Drilling debris in the oil-based drilling fluid is blocked by the porous partition 210 and flows to the upper part of the extraction tank 21. Drilling waste fluid passes through the porous partition 210 and enters the lower part of the extraction tank 21. Simultaneously, hot water is injected into the heating water jacket 22 through the water inlet pipe 220 on the heating water jacket 22 and circulated through the water outlet pipe 221 to heat the drilling debris and drilling waste fluid.

[0080] S4. Use the PLC controller to control the proportional regulating valve 100 and the driving motor 23 to open, so that the supercritical CO2 enters the two ends of the extraction tank 21 in proportion through the first Y-shaped conduit 10, and contacts the drilling debris and drilling waste liquid respectively; the driving motor 23 drives the first shaft 240 and the second shaft 241 to rotate respectively, and the first shaft 240 drives the connecting sleeve 251 and the hollow tube 250 to rotate simultaneously, so that when the mixing rod 254 rotates with the hollow tube 250, it rotates under the meshing action of the bevel gear 253 and the ring gear 255, and the drilling debris is continuously stirred by the stirring wheel 252. The supercritical CO2 is introduced into the interior of each hollow tube 250 by the second Y-shaped conduit 215, and sprayed onto the drilling debris through the injection head 2520 on the stirring wheel 252. The supercritical CO2 is fully contacted with the drilling debris; when the second shaft 241 rotates, the extrusion plate 260 slides up and down along the inner wall of the extraction tank 21, so that the mixture of drilling waste fluid and supercritical CO2 enters the liquid guide tube 261 under the extrusion action of the extrusion plate 260 and falls again into the interior of the extraction tank 21 through the liquid spray seat 2610; at the same time, when the second shaft 241 rotates, it drives the positioning sleeve 264 to rotate, and uses the sliding rod 263 to drive the stirring rod 265 and the mounting sleeve 262 to rotate; when the extrusion plate 260 moves up and down, the angle between the two stirring rods 265 on the same sliding sleeve 2630 changes continuously, so that the drilling waste fluid and supercritical CO2 are mixed more evenly, so that the supercritical CO2 extracts the oil phase of the drilling debris and drilling waste fluid;

[0081] S5. Use the PLC controller to control the control valve 200 to open, so that the supercritical CO2 and oil phase mixture enters the separation tank 30 through the output pipe 20; then control the pressure relief valve 301 to open, and the supercritical CO2 is converted into gaseous CO2 after the pressure is reduced. It is discharged and collected through the outlet pipe 300. When the CO2 gas rises inside the separation tank 30, the filter disc 31 is used to filter the oil mixed in the CO2 gas; the oil is discharged from the separation tank 30 through the oil outlet pipe 302 for collection;

[0082] S6. Open the movable cover 211 on the top of the extraction tank 21, clean the drilling debris blocked by the porous partition 210, and discharge the drilling waste liquid from which the oil is extracted from the extraction tank 21 through the liquid outlet pipe 212.

[0083] Example 7

[0084] like Figure 1The device for supercritical extraction of mineral oil from oil-based drilling fluid shown in the figure includes a CO2 storage assembly 1, a mineral oil extraction assembly 2 connected to the CO2 storage assembly 1 via a first Y-shaped conduit 10, a separation assembly 3 connected to the mineral oil extraction assembly 2 via an output pipe 20, and a PLC controller. The CO2 storage assembly 1, the mineral oil extraction assembly 2, and the separation assembly 3 are all disposed on a base 4. The CO2 storage assembly 1 includes a CO2 storage tank 11 with an air inlet pipe 110 disposed on the top and an electric heating coil 12 disposed therein, and a pressure pump 13 connected to the CO2 storage tank 11. A proportional regulating valve 100 is disposed on the first Y-shaped conduit 10, and a control valve 200 is disposed on the output pipe 20.

[0085] like Figure 1 、 2As shown in Figures 3, 4, 5, 6, 7 and 8, the mineral oil extraction assembly 2 includes an extraction tank 21 with a porous partition 210 at the upper position inside, a movable cover 211 clamped on the top, a liquid outlet pipe 212 at the lower position of the side wall, a heating water jacket 22 sleeved on the outside of the extraction tank 21, and a water inlet pipe 220 and a water outlet pipe 221 at the upper and lower ends of the side wall respectively, a driving motor 23 arranged on the top of the movable cover 211 and a mixing member 24 arranged inside the extraction tank 21 and connected to the driving motor 23; a lifting ear is provided on the movable cover 211, and a sealing ring is provided at the connection between the movable cover 211 and the extraction tank 21; two ports of the first Y-shaped conduit 10 respectively penetrate the heating water jacket 22 and are respectively connected to the upper and lower ends of the interior of the extraction tank 21 The movable cover 211 is connected to the extraction tank 21 by bolts, and a liquid inlet pipe 213 is provided on the movable cover 211; the mixing member 24 includes a first shaft 240 vertically passing through the movable cover 211 and connected to the output end of the drive motor 23, a second shaft 241 rotatably connected to the porous partition 210 and the bottom of the extraction tank 21 and connected to the first shaft 240 through a connector 2410, a first agitator 25 sleeved on the first shaft 240, and a second agitator 26 sleeved on the second shaft 241; the first agitator 25 includes a connecting sleeve 251 sleeved on the first shaft 240 and having four hollow tubes 250 distributed in a circumferential manner, a stirring wheel 252 rotatably connected to the hollow tube 250 and having an outer sleeve , a mixing rod 254 with a bevel gear 253 at one end away from the first shaft 240 and a gear ring 255 that is clamped inside the extraction tank 21 and meshed with the bevel gear 253; two first agitators 25 are provided, and the two first agitators 25 are arranged side by side inside the extraction tank 21. Air inlet grooves 214 are provided on the inner wall of the extraction tank 21 at positions corresponding to the positions of the two first agitators 25. A second Y-shaped conduit 215 that is respectively connected to the two air inlet grooves 214 and connected to the first Y-shaped conduit 10 is provided on the outer wall of the extraction tank 21. The ends of each hollow tube 250 are connected to the air inlet grooves 214 at the corresponding positions, and each stirring wheel 252 is provided with a spray head 25 that is connected to the interior of the hollow tube 250 at the corresponding position. 20; The second agitator 26 includes an extrusion plate 260 threadedly connected to the second shaft 241 and slidably engaged with the inner wall of the extraction tank 21; and 12 liquid guide tubes 261 vertically extending through the extrusion plate 260 and having a liquid spray seat 2610 rotatably engaged at the top. Mounting sleeves 262 corresponding to upper and lower positions are rotatably engaged with the lower bottom surface of the extrusion plate 260 and the inner bottom of the extraction tank 21. A retaining sleeve 264 with six sliding rods 263 circumferentially arranged thereon is slidably engaged with the second shaft 241. Each sliding rod 263 is provided with a sliding sleeve 2630. A stirring rod 265 is movably hinged to the upper and lower ends of each sliding sleeve 2630. The end of each stirring rod 265 away from the sliding sleeve 2630 is movably hinged to the mounting sleeve 262 at the corresponding position.

[0086] like Figure 1 、 9 As shown, the separation assembly 3 includes a separation tank 30 with an air outlet pipe 300 on the top, a pressure relief valve 301 on the upper side wall, an oil outlet pipe 302 on the lower side wall, and two filter discs 31 equidistantly arranged inside the separation tank 30; the proportional regulating valve 100, the control valve 200, and the pressure relief valve 301 are all electrically controlled valves; a cleaning motor 32 is provided on the top of the separation tank 30, the output shaft of which passes through the separation tank 30 and each filter disc 31 in sequence and is rotatably engaged with the bottom of the separation tank 30; a cleaning scraper 33 is sleeved on the output shaft and abuts against the lower bottom surface of each filter disc 31;

[0087] The PLC controller is electrically connected to the proportional regulating valve 100 , the control valve 200 , the pressure relief valve 301 , the electric heating coil 12 , the pressure pump 13 , the driving motor 23 and the cleaning motor 32 , respectively.

[0088] Example 8

[0089] This embodiment describes a method for supercritical extraction of mineral oil from oil-based drilling fluid using the apparatus of Example 7, comprising the following steps:

[0090] S1. Connect the proportional control valve 100, the control valve 200, the pressure relief valve 301, the electric heating coil 12, the pressure pump 13, the drive motor 23 and the cleaning motor 32 to an external power source respectively;

[0091] S2. Inject CO2 gas into the CO2 storage tank 11 through the air inlet pipe 110 on the CO2 storage tank 11, and use the PLC controller to control the electric heating coil 12 and the pressure pump 13 to turn on, so that the CO2 gas is converted to a supercritical state;

[0092] S3. Injecting oil-based drilling fluid into the extraction tank 21 through the liquid inlet pipe 213 on the extraction tank 21. Drilling debris in the oil-based drilling fluid is blocked by the porous partition 210 and flows to the upper part of the extraction tank 21. Drilling waste fluid passes through the porous partition 210 and enters the lower part of the extraction tank 21. Simultaneously, hot water is injected into the heating water jacket 22 through the water inlet pipe 220 on the heating water jacket 22 and circulated through the water outlet pipe 221 to heat the drilling debris and drilling waste fluid.

[0093] S4, use the PLC controller to control the proportional regulating valve 100 and the driving motor 23 to open, so that the supercritical CO2 enters the two ends of the extraction tank 21 in proportion through the first Y-shaped conduit 10, and contacts the drilling debris and drilling waste liquid respectively; the driving motor 23 drives the first shaft 240 and the second shaft 241 to rotate respectively, and the first shaft 240 drives the connecting sleeve 251 and the hollow tube 250 to rotate simultaneously, so that when the mixing rod 254 rotates with the hollow tube 250, it rotates under the meshing action of the bevel gear 253 and the ring gear 255, and the drilling debris is continuously stirred by the stirring wheel 252, and the supercritical CO2 is introduced into each hollow tube 250 by the second Y-shaped conduit 215, and sprayed into the drilling debris through the injection head 2520 on the stirring wheel 252, so that the supercritical CO2 is fully in contact with the drilling debris; when the second shaft 241 rotates, the extrusion plate 260 rotates along the extraction The inner wall of the tank 21 slides up and down, so that the mixture of drilling waste fluid and supercritical CO2 enters the liquid guide tube 261 under the squeezing action of the squeezing plate 260 and falls again into the interior of the extraction tank 21 through the liquid spraying seat 2610. At the same time, when the second shaft 241 rotates, it drives the locking sleeve 264 to rotate, and the sliding rod 263 drives the stirring rod 265 and the mounting sleeve 262 to rotate. When the squeezing plate 260 moves up and down, the angle between the two stirring rods 265 on the same sliding sleeve 2630 changes continuously, thereby making the drilling waste fluid and supercritical CO2 mix more evenly, so that the supercritical CO2 extracts the oil phase of the drilling debris and drilling waste fluid. The extraction tank 21 is provided with two sealing sleeves 27 respectively mounted on the outside of the two gear rings 255. The sealing sleeve 27 is slidably engaged with a rotating sleeve 270, and each hollow tube 250 is rotatably engaged with the rotating sleeve 270 at the corresponding position.

[0094] S5. Use the PLC controller to control the control valve 200 and the motor 32 to start, so that the supercritical CO2 and oil phase mixture enters the separation tank 30 through the output pipe 20; then control the pressure relief valve 301 to open, and the supercritical CO2 is converted into gaseous CO2 after the pressure is reduced, and is discharged and collected through the outlet pipe 300. When the CO2 gas rises inside the separation tank 30, the filter disc 31 is used to filter the oil mixed in the CO2 gas; use the PLC controller to control the cleaning motor 32 to start, and use the cleaning scraper 33 to clean the oil accumulated at the lower end of the filter disc 31; the oil is discharged from the separation tank 30 through the oil outlet pipe 302 for collection;

[0095] S6. Open the movable cover 211 on the top of the extraction tank 21, clean the drilling debris blocked by the porous partition 210, and discharge the drilling waste liquid from which the oil is extracted from the extraction tank 21 through the liquid outlet pipe 212.

[0096] It should be noted that the PLC controller, proportional control valve 100, control valve 200, pressure relief valve 301, electric heating coil 12, pressure pump 13, drive motor 23 and cleaning motor 32 used in the present invention all adopt existing technologies and are not specifically limited here. The corresponding products can be selected according to actual needs.

Claims

1. A device for supercritical extraction of mineral oil from oil-based drilling fluid, characterized in that: It comprises a CO2 storage component (1), a mineral oil extraction component (2) connected to the CO2 storage component (1) via a first Y-shaped conduit (10), and a separation component (3) connected to the mineral oil extraction component (2) via an output pipe (20); The CO2 storage component (1), the mineral oil extraction component (2) and the separation component (3) are all arranged on a base (4); the CO2 storage component (1) comprises a CO2 storage tank (11) with an air inlet pipe (110) arranged on the top, an electric heating coil (12) arranged inside, and a pressure pump (13) connected to the CO2 storage tank (11); a proportional regulating valve (100) is arranged on the first Y-shaped conduit (10), and a control valve (200) is arranged on the output pipe (20); The mineral oil extraction assembly (2) comprises an extraction tank (21) with a porous partition (210) arranged at an upper position inside, a movable cover (211) clamped at the top, a liquid outlet pipe (212) arranged at a lower position of the side wall, a heating water jacket (22) sleeved on the outside of the extraction tank (21) and provided with a water inlet pipe (220) and a water outlet pipe (221) at the upper and lower ends of the side wall, a driving motor (23) arranged on the top of the movable cover (211), and a mixing member (24) arranged inside the extraction tank (21) and connected to the driving motor (23); two ports of the first Y-shaped conduit (10) respectively penetrate the heating water jacket (22) and are respectively connected to the extraction tank (21). The upper and lower ends of the tank (21) are connected, the movable cover (211) is connected to the extraction tank (21) by bolts, and a liquid inlet pipe (213) is provided on the movable cover (211); the mixing component (24) comprises a first shaft (240) vertically penetrating the movable cover (211) and connected to the output end of the driving motor (23), a second shaft (241) rotatably engaged with the porous partition (210) and the bottom of the extraction tank (21) respectively and engaged with the first shaft (240) through a connector (2410), a first stirrer (25) sleeved on the first shaft (240), and a second stirrer (26) sleeved on the second shaft (241); The separation assembly (3) comprises a separation tank (30) having an air outlet pipe (300) arranged on the top, a pressure relief valve (301) arranged at the upper position of the side wall, an oil outlet pipe (302) arranged at the lower position of the side wall, and a plurality of filter discs (31) arranged at equal distances inside the separation tank (30).

2. The device for supercritical extraction of mineral oil from oil-based drilling fluid according to claim 1, characterized in that: The first agitator (25) comprises a connecting sleeve (251) sleeved on the first shaft (240) and having a plurality of hollow tubes (250) distributed in a circumferentially scattered manner, a mixing rod (254) rotatably engaged with the hollow tubes (250) and having a stirring wheel (252) sleeved on the outside, a bevel gear (253) provided at one end away from the first shaft (240), and a gear ring (255) engaged in the extraction tank (21) and meshing with the bevel gear (253).

3. The device for supercritical extraction of mineral oil from oil-based drilling fluid according to claim 2, characterized in that: Two first agitators (25) are provided, and the two first agitators (25) are arranged side by side in the upper and lower parts inside the extraction tank (21). An air inlet groove (214) is provided on the inner wall of the extraction tank (21) at positions corresponding to the positions of the two first agitators (25). A second Y-shaped conduit (215) is provided on the outer wall of the extraction tank (21) and is connected to the two air inlet grooves (214) and the first Y-shaped conduit (10). The ends of each hollow tube (250) are connected to the air inlet groove (214) at the corresponding position, and each stirring wheel (252) is provided with a spray head (2520) that is connected to the inside of the hollow tube (250) at the corresponding position.

4. The device for supercritical extraction of mineral oil from oil-based drilling fluid according to claim 3, characterized in that: Two sealing sleeves (27) are provided inside the extraction tank (21) and are respectively sleeved on the outside of the two gear rings (255). A rotating sleeve (270) is slidably engaged with the sealing sleeve (27), and each hollow tube (250) is rotatably engaged with the rotating sleeve (270) at a corresponding position.

5. The device for supercritical extraction of mineral oil from oil-based drilling fluid according to claim 1, characterized in that: The second agitator (26) includes an extrusion plate (260) threadedly connected to the second shaft (241) and slidably engaged with the inner wall of the extraction tank (21), and a plurality of liquid guide tubes (261) vertically penetrating the extrusion plate (260) and having a liquid spray seat (2610) rotatably engaged at the top.

6. The device for supercritical extraction of mineral oil from oil-based drilling fluid according to claim 5, characterized in that: The lower surface of the extrusion plate (260) and the inner bottom of the extraction tank (21) are both rotatably engaged with mounting sleeves (262) corresponding to the upper and lower positions; the second shaft (241) is slidably engaged with a positioning sleeve (264) on which a plurality of sliding rods (263) are circumferentially arranged; each of the sliding rods (263) is provided with a sliding sleeve (2630); and each of the upper and lower ends of the sliding sleeve (2630) is movably hinged with a stirring rod (265); and one end of each stirring rod (265) away from the sliding sleeve (2630) is movably hinged to the mounting sleeve (262) at the corresponding position.

7. The device for supercritical extraction of mineral oil from oil-based drilling fluid according to claim 1, characterized in that: The top of the separation tank (30) is provided with an output shaft which sequentially passes through the separation tank (30) and each filter disc (31) and then is rotatably engaged with the bottom of the separation tank (30). A cleaning scraper (33) is sleeved on the output shaft and abuts against the bottom surface of each filter disc (31).

8. The device for supercritical extraction of mineral oil from oil-based drilling fluid according to claim 1, characterized in that: The movable cover (211) is provided with a lifting lug, and a sealing ring is provided at the connection between the movable cover (211) and the extraction tank (21).

9. A method for supercritical extraction of mineral oil from oil-based drilling fluid using the device according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Connect the proportional control valve (100), the control valve (200), the pressure relief valve (301), the electric heating coil (12), the pressure pump (13), and the drive motor (23) to an external power source respectively; S2, injecting CO2 gas into the interior of the CO2 storage tank (11) through the air inlet pipe (110) on the CO2 storage tank (11), and turning on the electric heating coil (12) and the pressure pump (13) to convert the CO2 gas into a supercritical state; S3, injecting the oil-based drilling fluid into the extraction tank (21) through the liquid inlet pipe (213) on the extraction tank (21), the drilling debris in the oil-based drilling fluid is blocked by the porous partition (210) to the upper part of the extraction tank (21), and the drilling waste fluid enters the lower part of the extraction tank (21) through the porous partition (210); at the same time, injecting hot water into the heating water jacket (22) through the water inlet pipe (220) on the heating water jacket (22), and circulating it through the water outlet pipe (221), thereby heating the drilling debris and the drilling waste fluid; S4, opening the proportional regulating valve (100) and the driving motor (23), so that the supercritical CO2 enters the two ends of the extraction tank (21) in proportion through the first Y-shaped conduit (10), and contacts the drilling debris and the drilling waste liquid respectively; the driving motor (23) drives the first shaft (240) and the second shaft (241) to rotate respectively; the first shaft (240) drives the first stirrer (25) to rotate during the rotation process, so that the supercritical CO2 contacts the drilling debris fully; the second shaft (241) drives the second stirrer (26) to rotate during the rotation process, so that the supercritical CO2 contacts the drilling waste liquid fully; so that the supercritical CO2 extracts the oil phase of the drilling debris and the drilling waste liquid; S5. Open the control valve (200) to allow the supercritical CO2 and oil phase mixture to enter the separation tank (30) through the output pipe (20); then open the pressure relief valve (301), and the supercritical CO2 is converted into gaseous CO2 after the pressure is reduced, and discharged and collected through the outlet pipe (300); when the CO2 gas rises inside the separation tank (30), the filter disc (31) is used to filter the oil mixed in the CO2 gas; the oil is discharged from the separation tank (30) through the oil outlet pipe (302) for collection; S6. Open the movable cover (211) at the top of the extraction tank (21), clean the drilling debris blocked by the porous partition (210), and discharge the drilling waste liquid from which the oil is extracted from the extraction tank (21) through the liquid outlet pipe (212).

10. The device for supercritical extraction of mineral oil from oil-based drilling fluid according to claim 1, characterized in that: The movable cover (211) is provided with a lifting lug.

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