An oil-based rock cuttings oil purification device and treatment method

Abstract

A purification device and treatment method for oil-based rock cuttings oil, relating to the field of oil and gas pollution technology, is disclosed. The treatment method includes: S1, the oil-based rock cuttings oil is preheated and then enters a first evaporator for flash evaporation to separate light and heavy components; S2, the light components are cooled to obtain light oil, which is then sent to a first temporary storage container, while the remaining non-condensable gas is sent to a vacuum line; S3, the heavy components are transported to a second temporary storage container, where a portion of the material is returned to the first evaporator for recycling, and the remaining material is transported to a second evaporator for secondary separation; S4, the light components separated in the second evaporator are cooled to obtain light oil and non-condensable gas; a portion of the heavy components separated in the second evaporator are heated and returned to the second evaporator for recycling, while the remaining heavy components are cooled and returned to the raw material tank. This invention further processes oil-based rock cuttings oil to obtain a bright yellow light oil, which can be used as industrial fuel oil with higher added value.

Description

Technical Field

[0001] This invention relates to the field of oil and gas pollution technology, and in particular to an oil-based rock cuttings oil purification device and treatment method. Background Technology

[0002] In shale gas exploration and extraction, drilling fluid is injected to lubricate and cool the drill bit. Oil-based drilling fluid can reduce cuttings shedding and produce fewer drill cuttings, but it generates slag-containing waste liquid mixed with cuttings and other impurities. This slag-containing waste liquid can be treated by distillation or pressure filtration to obtain a brown liquid with no obvious impurities, namely oil-based cuttings oil. Oil-based cuttings oil suffers from low quality, difficulty in removing water, poor light transmittance, and a strong odor, resulting in low added value and low utilization rate. Summary of the Invention

[0003] To address the issue of low added value of oil-based rock cuttings oil in existing technologies, this invention provides an oil-based rock cuttings oil purification device and treatment method.

[0004] This invention provides the following technical solution: an oil-based rock cuttings oil purification device, characterized in that it includes a raw material container, which is connected to the low-temperature inlet of a first heat exchanger via a pipeline, and the low-temperature outlet of the first heat exchanger is connected to the feed inlet of a first evaporator; the light component outlet of the first evaporator is connected to the high-temperature inlet of the first heat exchanger, the high-temperature liquid outlet of the first heat exchanger is connected to a first temporary storage container, and the high-temperature gas outlet of the first heat exchanger is connected to a vacuum pump; the heavy component outlet of the first evaporator is connected to the feed inlet of a second temporary storage container, and the outlet of the second temporary storage container is connected to the feed inlets of the first evaporator and the second evaporator via different pipelines; the light component outlet of the second evaporator is connected to the high-temperature inlet of the first heat exchanger, and the heavy component outlet of the second evaporator is connected to the low-temperature inlet of the second heat exchanger and the raw material container via different pipelines, and the low-temperature outlet of the second heat exchanger is connected to the feed inlet of the second evaporator.

[0005] Preferably, the raw material container is connected to the low-temperature inlet of the third heat exchanger via a pipeline, and the low-temperature outlet of the third heat exchanger is connected to the low-temperature inlet of the first heat exchanger; the heavy component outlet of the second evaporator is connected to the high-temperature inlet of the third heat exchanger via a pipeline, and the high-temperature outlet of the third heat exchanger is connected to the raw material container.

[0006] Preferably, the high-temperature gas outlet of the first heat exchanger is connected to the high-temperature inlet of the fourth heat exchanger, the high-temperature gas outlet of the fourth heat exchanger is connected to the vacuum pipe, the high-temperature liquid outlet of the fourth heat exchanger is connected to the high-temperature inlet of the fifth heat exchanger, the high-temperature outlet of the fifth heat exchanger is connected to the first temporary storage container, and both the fourth and fifth heat exchangers are connected to cooling water pipes.

[0007] Preferably, the gas outlet of the second temporary storage container is connected to the high-temperature inlet of the first heat exchanger.

[0008] Preferably, both the first evaporator and the second evaporator are equipped with a heat transfer oil heat exchange system, and the high-temperature inlet and high-temperature outlet of the second heat exchanger are connected to heat transfer oil pipes.

[0009] A treatment method applied to an oil-based rock cuttings oil refining unit includes the following steps: S1, after preheating, the oil-based rock cuttings oil enters the first evaporation unit, where it is flash-separated to obtain light and heavy components; S2, the light component is cooled to obtain light oil, the light oil is sent into the first temporary storage container, and the remaining non-condensable gas is sent to the vacuum line. S3, the recombinant components are conveyed to the second temporary storage container, and part of the material in the second temporary storage container is returned to the first evaporation device for recycling, while the remaining material is conveyed to the second evaporation device for secondary separation; S4, the light components separated by the second evaporator are cooled to obtain light oil, which is sent to the first temporary storage container, and the remaining non-condensable gas is sent to the vacuum line; some of the heavy components separated by the second evaporator are heated and returned to the second evaporator for circulation, while the remaining heavy components are cooled and returned to the raw material tank. In steps S3 and S4, the proportion of the partial material is 0-100%, and the proportion of the partial heavy component is 0-100%.

[0010] Preferably, in step S1, the mid-section recovery temperature of the first evaporator is 200~220℃, the top temperature is 140~160℃, and the pressure inside the tower is -95 kPa; in step S3, the proportion of material returned to the first evaporator for circulation is 100%.

[0011] Preferably, in step S1, the temperature of the bottom of the first evaporator is 200~220℃ and the pressure inside the tower is -70kPa; in step S4, the temperature of the bottom of the second evaporator is 220~240℃, the temperature at the top of the tower is stable at 140~160℃, and the pressure inside the tower is -95 kPa.

[0012] Preferably, in step S1, the temperature of the bottom of the first evaporator is 160~180℃ and the pressure inside the tower is ±0 kPa; in step S4, the temperature of the bottom of the second evaporator is 300~320℃ and the pressure inside the tower is ±0 kPa.

[0013] Preferably, in step S1, the waste heat of the heavy components of the second evaporator is used to preheat the oil-based rock cuttings oil for the first time; and the waste heat of the light components of the first evaporator, the second evaporator, and the second temporary storage container is used to preheat the oil-based rock cuttings oil for the second time.

[0014] The beneficial effects of this invention are: further processing oil-based rock cuttings oil to obtain a bright yellow light oil with lower mechanical impurity content, increased light transmittance, and lower water content, which can be used as industrial fuel oil with higher added value. Attached Figure Description

[0015] Figure 1 Device connection for one embodiment of the purification apparatus Figure I .

[0016] Figure 2 Device connection for one embodiment of the purification apparatus Figure II .

[0017] Reference numerals: 11-First heat exchanger, 12-Second heat exchanger, 13-Third heat exchanger, 14-Fourth heat exchanger, 15-Fifth heat exchanger, 21-First evaporation device, 22-Second evaporation device, 31-First temporary storage container, 32-Second temporary storage container, 41-First transfer pump, 42-Second transfer pump, 43-Third transfer pump. Detailed Implementation

[0018] The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings and reference numerals, so that those skilled in the art can implement them after reading this specification. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0019] Example 1

[0020] This invention provides an oil-based rock cuttings oil purification device, including a raw material container, multiple heat exchangers, a first evaporation device, a second evaporation device, a first temporary storage container, a second temporary storage container, a vacuum pump, etc. Please refer to... Figure 1 , 2 The above-mentioned equipment is connected by pipes, which are equipped with corresponding valves, delivery pumps and other components. Liquids flow by gravity or are pressurized by delivery pumps in the pipes, while gases flow under the negative pressure created by vacuum pumps.

[0021] The raw material container can be a raw material tank or a raw material barrel, which contains the oil-based rock cuttings oil to be processed. The plurality of heat exchangers includes a first heat exchanger 11, a second heat exchanger 12, a third heat exchanger 13, a fourth heat exchanger 14, and a fifth heat exchanger 15. The first heat exchanger 11 and the third heat exchanger 13 utilize the residual heat of the intermediate product to preheat the oil-based rock cuttings oil. The second heat exchanger 12 utilizes the heat of the heat transfer oil to heat the heavy components of the second evaporation device. The fourth heat exchanger 14 and the fifth heat exchanger 15 utilize cooling water to cool the light oil. In other embodiments, the number of heat exchangers can be selected according to actual needs. The first evaporation device 21 and the second evaporation device 22 can both be evaporation towers, evaporation tanks, or other evaporation equipment for flash separation of materials. Heating methods can include heat transfer oil, molten salt, electric heating, etc. In this embodiment, both are equipped with a heat transfer oil heat exchange system, with heating achieved by heat transfer oil. The first temporary storage container 31 and the second temporary storage container 32 can both be temporary storage tanks and are both equipped with discharge valves.

[0022] Please refer to the device connection method. Figure 1 , 2 The raw material container is connected to the low-temperature inlet of the third heat exchanger 13 via a pipe, the low-temperature outlet of the third heat exchanger 13 is connected to the low-temperature inlet of the first heat exchanger 11 via a pipe, and the low-temperature outlet of the first heat exchanger 11 is connected to the feed inlet of the first evaporation device 21.

[0023] The light component outlet of the first evaporator 21 is connected to the high-temperature inlet of the first heat exchanger 11 via a gas phase pipeline. The high-temperature gas outlet of the first heat exchanger 11 is connected to the high-temperature inlet of the fourth heat exchanger 14. The high-temperature gas outlet of the fourth heat exchanger 14 is connected to a vacuum pump via a vacuum pipeline. The high-temperature liquid outlets of both the first heat exchanger 11 and the fourth heat exchanger 14 are connected to the high-temperature inlet of the fifth heat exchanger 15. The high-temperature outlet of the fifth heat exchanger 15 is connected to the first temporary storage container 31. The low-temperature inlets and outlets of the fourth and fifth heat exchangers are all connected to cooling water pipes. The first temporary storage container 31 is connected to the product tank via a pipeline, and a first transfer pump 41 is installed on the pipeline.

[0024] The heavy component outlet of the first evaporator 21 is connected to the inlet of the second temporary storage container 32. The outlet of the second temporary storage container 32 is connected to the inlets of the first evaporator 21 and the second evaporator 22 via different pipes. Each pipe is equipped with a second transfer pump 42 and a valve, allowing some material to return to the first evaporator 21 for circulation, while some material enters the second evaporator 22 for secondary separation. The gas outlet of the second temporary storage container 32 is also connected to the high-temperature inlet of the first heat exchanger 11 via a pipe.

[0025] The light component outlet of the second evaporator 22 is connected to the high-temperature inlet of the first heat exchanger 11. The heavy component outlet of the second evaporator 22 is connected to the low-temperature inlet of the second heat exchanger 12 and the high-temperature inlet of the third heat exchanger 13 via different pipes, and each pipe is equipped with a third transfer pump 43 and a valve; the low-temperature outlet of the second heat exchanger 12 is connected to the feed inlet of the second evaporator 22, and both the high-temperature inlet and high-temperature outlet of the second heat exchanger 12 are connected to heat transfer oil pipes; the high-temperature outlet of the third heat exchanger 13 is connected to the raw material container.

[0026] Example 2

[0027] This invention provides a treatment method for an oil-based rock cuttings oil purification device, the treatment equipment of which is based on the purification device provided in Example 1. The treatment method includes the following steps.

[0028] S1, the oil-based rock cuttings oil, after preheating, enters the first evaporation unit for flash separation to obtain light and heavy components. Specifically, the oil-based rock cuttings oil in the raw material container sequentially enters the third heat exchanger 13 and the first heat exchanger 11 for preheating twice before entering the first evaporation unit 21 for flash separation. The first evaporation unit 21 adopts an evaporation tower heated by heat transfer oil, with a middle section recovery temperature of 200~220℃, a tower top temperature of 140~160℃, and a tower pressure controlled at -95 kPa to achieve vacuum distillation, separating the oil-based rock cuttings oil into light and heavy components, with the light components being gaseous and the heavy components being liquid.

[0029] S2, the light component is cooled to obtain light oil, the light oil is sent to the first temporary storage container, and the remaining non-condensable gas is sent to the vacuum pipeline. The specific process is as follows.

[0030] The vacuum pump starts to create negative pressure, transporting the light components in the first evaporator 21 through the gas phase pipeline to the first heat exchanger 11. The light components are condensed into light oil using the lower-temperature oil-based rock cuttings oil. The remaining gas enters the fourth heat exchanger 14, where it is cooled again by cooling water and condenses into light oil. The remaining non-condensable gas enters the vacuum line. The light oil condensed in the first and fourth heat exchangers enters the fifth heat exchanger 15, is cooled again by cooling water, and then transported to the first temporary storage container 31. When the liquid level in the first temporary storage container 31 reaches the designed height, the first transfer pump 41 is started to deliver the light oil into the product container.

[0031] S3, the heavy components are transported to the second temporary storage container 32, and then the material in the second temporary storage container 32 is pumped back to the first evaporation device 21 by the second transfer pump 42 for circulation, thereby realizing single-tower distillation.

[0032] Example 3

[0033] This invention provides a treatment method for an oil-based rock cuttings oil purification device, the treatment equipment of which is based on the purification device provided in Example 1. The treatment method includes the following steps.

[0034] S1, the oil-based rock cuttings oil, after preheating, enters the first evaporation unit for flash separation to obtain light and heavy components. Specifically, the oil-based rock cuttings oil in the raw material container sequentially enters the third heat exchanger 13 and the first heat exchanger 11 for preheating twice before entering the first evaporation unit 21 for flash separation. The first evaporation unit 21 adopts an evaporation tower heated by heat transfer oil, with a tower bottom temperature of 200~220℃ and a gradual decrease in temperature from bottom to top. The pressure inside the tower is controlled at -70 kPa to achieve vacuum distillation, separating the oil-based rock cuttings oil into light and heavy components. The light components are gaseous, and the heavy components are liquid.

[0035] S2, the light component is cooled to obtain light oil, the light oil is sent to the first temporary storage container, and the remaining non-condensable gas is sent to the vacuum pipeline. The specific process is as follows.

[0036] The vacuum pump starts to create negative pressure, transporting the light components in the first evaporator 21 through the gas phase pipeline to the first heat exchanger 11. The light components are condensed into light oil using the lower-temperature oil-based rock cuttings oil. The remaining gas enters the fourth heat exchanger 14, where it is cooled again by cooling water and condenses into light oil. The remaining non-condensable gas enters the vacuum line. The light oil condensed in the first and fourth heat exchangers enters the fifth heat exchanger 15, is cooled again by cooling water, and then transported to the first temporary storage container 31. When the liquid level in the first temporary storage container 31 reaches the designed height, the first transfer pump 41 is started to deliver the light oil into the product container.

[0037] S3, the recombinant components are transported to the second temporary storage container 32. Part of the material in the second temporary storage container 32 is returned to the first evaporation device 21 for circulation, while the remaining material is transported by the second transfer pump 42 to the second evaporation device 22 for secondary separation.

[0038] S4, the light components separated by the second evaporator are condensed to obtain light oil, which is sent to the first temporary storage container, and the remaining non-condensable gas is sent to the vacuum line; some of the heavy components separated by the second evaporator are returned to the second evaporator for circulation after heating, and some of the heavy components are returned to the raw material tank after cooling; the specific process is as follows.

[0039] The second evaporation unit 22 also employs an evaporation tower, with a bottom temperature of 220~240℃ and a gradually decreasing temperature from bottom to top, reaching 140~160℃ at the top. The pressure inside the tower is controlled at -95 kPa, achieving vacuum distillation. After secondary separation, gaseous light components and liquid heavy components are obtained. The light component outlet at the top of the second evaporation unit 22 is connected to the gas phase pipeline of the first evaporation unit 21. The gaseous light components also enter the first heat exchanger 11 and the fourth heat exchanger 14 under the negative pressure generated by the vacuum pump, where they are condensed to obtain light oil. The non-condensable gas enters the vacuum pipeline, and the light oil is further cooled by the fifth heat exchanger 15 before entering the first temporary storage container 31. The heavy component outlet of the second evaporator 22 is connected to the low-temperature inlet of the second heat exchanger 12 and the high-temperature inlet of the third heat exchanger 13 through different pipes. Some of the heavy components enter the second heat exchanger 12, which can use heat transfer oil, molten salt or steam to heat the heavy components and then return them to the second evaporator 22 for circulation. The remaining heavy components are transported to the third heat exchanger 13 by the third transfer pump 43, and then returned to the raw material container after the waste heat is used to heat the oil-based rock cuttings oil.

[0040] Example 4

[0041] This invention provides a treatment method for an oil-based rock cuttings oil purification device, the treatment equipment of which is based on the purification device provided in Example 1. The treatment method includes the following steps.

[0042] S1, the oil-based rock cuttings oil, after preheating, enters the first evaporation unit for flash separation to obtain light and heavy components. Specifically, the oil-based rock cuttings oil in the raw material container sequentially enters the third heat exchanger 13 and the first heat exchanger 11 for preheating twice before entering the first evaporation unit 21 for flash separation. The first evaporation unit 21 adopts an evaporation tower heated by heat transfer oil, with a tower bottom temperature of 160~180℃ and a gradual decrease in temperature from bottom to top. The pressure inside the tower is controlled at ±0 kPa to achieve atmospheric pressure distillation, separating the oil-based rock cuttings oil into light and heavy components. The light components are gaseous, and the heavy components are liquid.

[0043] S2, the light component is cooled to obtain light oil, the light oil is sent to the first temporary storage container, and the remaining non-condensable gas is sent to the vacuum pipeline. The specific process is as follows.

[0044] The vacuum pump starts to create negative pressure, transporting the light components in the first evaporation unit 21 through the gas phase pipeline to the first heat exchanger 11. The light components are condensed into light oil using low-temperature oil-based rock cuttings. The remaining gas enters the fourth heat exchanger 14, where it is cooled again by cooling water and condenses into light oil. The remaining non-condensable gas enters the vacuum line. The light oil condensed in the first and fourth heat exchangers enters the fifth heat exchanger 15, is cooled again by cooling water, and then transported to the first temporary storage container 31. When the liquid level in the first temporary storage container 31 reaches the designed height, the first transfer pump 41 is started to deliver the light oil into the product container.

[0045] S3, the recombinant components are transported to the second temporary storage container 32. Part of the material in the second temporary storage container 32 is returned to the first evaporation device 21 for circulation, while the remaining material is transported by the second transfer pump 42 to the second evaporation device 22 for secondary separation.

[0046] S4, the light components separated by the second evaporator are cooled to obtain light oil, which is sent to the first temporary storage container, and the remaining non-condensable gas is sent to the vacuum line; some of the heavy components separated by the second evaporator are heated and returned to the second evaporator for circulation, while some of the heavy components are cooled and returned to the raw material tank; the specific process is as follows.

[0047] The second evaporation unit 22 also employs an evaporation tower, with a bottom temperature of 300~320℃. The temperature inside the tower gradually decreases from bottom to top, and the pressure inside the tower is controlled at ±0 kPa to achieve atmospheric distillation. After secondary separation, gaseous light components and liquid heavy components are obtained. The light component outlet at the top of the second evaporation unit 22 is connected to the gas phase pipeline of the first evaporation unit 21. The gaseous light components also enter the first heat exchanger 11 and the fourth heat exchanger 14 under the negative pressure generated by the vacuum pump, where they are condensed to obtain light oil. The non-condensable gas enters the vacuum pipeline, and the light oil is cooled again by the fifth heat exchanger 15 before entering the first temporary storage container 31. The heavy component outlet of the second evaporator 22 is connected to the low-temperature inlet of the second heat exchanger 12 and the high-temperature inlet of the third heat exchanger 13 through different pipes. Some of the heavy components enter the second heat exchanger 12, which can use heat transfer oil, molten salt or steam to heat the heavy components and then return them to the second evaporator 22 for circulation. The remaining heavy components are transported to the third heat exchanger 13 by the third transfer pump 43, and then returned to the raw material container after the waste heat is used to heat the oil-based rock cuttings oil.

[0048] Using the processing methods provided in Examples 2, 3, and 4, the resulting light oil is bright yellow, with lower mechanical impurity content, increased light transmittance, and lower water content compared to oil-based rock cuttings oil, making it suitable for use as industrial fuel oil. The oil-based rock cuttings oil raw material used in Example 3 and the resulting light oil were tested according to the provisions of GB 17411-2015 Marine Fuel Oil, and all indicators of the light oil met the national standard requirements.

[0049] The above describes one or more embodiments of the present invention in a relatively specific and detailed manner, but it should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. An oil-based rock cuttings oil purification device, characterized in that, The device includes a raw material container connected via a pipe to the low-temperature inlet of a first heat exchanger, the low-temperature outlet of the first heat exchanger connected to the feed inlet of a first evaporator; a light component outlet of the first evaporator connected to the high-temperature inlet of the first heat exchanger, a high-temperature liquid outlet of the first heat exchanger connected to a first temporary storage container, and a high-temperature gas outlet of the first heat exchanger connected to a vacuum pump; a heavy component outlet of the first evaporator connected to the feed inlet of a second temporary storage container, the discharge outlet of the second temporary storage container connected via different pipes to the feed inlets of the first and second evaporators respectively; a light component outlet of the second evaporator connected to the high-temperature inlet of the first heat exchanger, a heavy component outlet of the second evaporator connected via different pipes to the low-temperature inlet of the second heat exchanger and the raw material container respectively, and a low-temperature outlet of the second heat exchanger connected to the feed inlet of the second evaporator.

2. The oil-based rock cuttings oil purification device according to claim 1, characterized in that, The raw material container is connected to the low-temperature inlet of the third heat exchanger via a pipeline, and the low-temperature outlet of the third heat exchanger is connected to the low-temperature inlet of the first heat exchanger; the heavy component outlet of the second evaporator is connected to the high-temperature inlet of the third heat exchanger via a pipeline, and the high-temperature outlet of the third heat exchanger is connected to the raw material container.

3. The oil-based rock cuttings oil purification device according to claim 1, characterized in that, The high-temperature gas outlet of the first heat exchanger is connected to the high-temperature inlet of the fourth heat exchanger, the high-temperature gas outlet of the fourth heat exchanger is connected to the vacuum pipe, the high-temperature liquid outlet of the fourth heat exchanger is connected to the high-temperature inlet of the fifth heat exchanger, the high-temperature outlet of the fifth heat exchanger is connected to the first temporary storage container, and both the fourth and fifth heat exchangers are connected to cooling water pipes.

4. The oil-based rock cuttings oil purification device according to claim 1, characterized in that, The gas outlet of the second temporary storage container is connected to the high-temperature inlet of the first heat exchanger.

5. The oil-based rock cuttings oil purification device according to claim 1, characterized in that, Both the first evaporator and the second evaporator are equipped with a heat transfer oil heat exchange system, and the high-temperature inlet and high-temperature outlet of the second heat exchanger are connected to heat transfer oil pipes.

6. A treatment method applied to an oil-based rock cuttings oil purification device according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1, after preheating, the oil-based rock cuttings oil enters the first evaporation unit, where it is flash-separated to obtain light and heavy components; S2, the light component is cooled to obtain light oil, the light oil is sent into the first temporary storage container, and the remaining non-condensable gas is sent to the vacuum line. S3, the recombinant components are conveyed to the second temporary storage container, and part of the material in the second temporary storage container is returned to the first evaporation device for recycling, while the remaining material is conveyed to the second evaporation device for secondary separation; S4, the light components separated by the second evaporator are cooled to obtain light oil, the light oil is sent to the first temporary storage container, and the remaining non-condensable gas is sent to the vacuum line. Some of the heavy components separated by the second evaporator are heated and then returned to the second evaporator for circulation, while the remaining heavy components are cooled and returned to the raw material tank. In steps S3 and S4, the proportion of the partial material is 0-100%, and the proportion of the partial heavy component is 0-100%.

7. The treatment method according to claim 6, characterized in that, In step S1, the mid-section recovery temperature of the first evaporator is 200~220℃, the top temperature is 140~160℃, and the pressure inside the tower is -95 kPa; in step S3, the proportion of material returned to the first evaporator for circulation is 100%.

8. The treatment method according to claim 6, characterized in that, In step S1, the temperature of the bottom of the first evaporator is 200~220℃ and the pressure inside the tower is -70kPa; in step S4, the temperature of the bottom of the second evaporator is 220~240℃, the temperature at the top of the tower is stable at 140~160℃, and the pressure inside the tower is -95 kPa.

9. The treatment method according to claim 6, characterized in that, In step S1, the temperature of the bottom of the first evaporator is 160~180℃ and the pressure inside the tower is ±0 kPa; in step S4, the temperature of the bottom of the second evaporator is 300~320℃ and the pressure inside the tower is ±0 kPa.

10. The treatment method according to claim 6, characterized in that, In step S1, the waste heat of the heavy components of the second evaporator is used to preheat the oil-based rock cuttings oil for the first time; the waste heat of the light components of the first evaporator, the second evaporator, and the second temporary storage container is used to preheat the oil-based rock cuttings oil for the second time.

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