阅读说明：本技术 一种从油基岩屑回收基础油的方法 (Method for recovering base oil from oil-based rock debris ) 是由 彭春耀 左京杰 骆小虎 张鑫 何睿 冯彦林 王瑞迪 杨勇 刘乐 杨洋 于 2019-08-23 设计创作，主要内容包括：本申请涉及一种从油基岩屑回收基础油的方法,包括进料阶段、升温阶段、恒温阶段和冷却阶段；其中,在升温阶段和恒温阶段,按照150rpm的搅拌速度搅拌所述油基岩屑,并使反应体系的压力维持在-0.042MPa至-0.047MPa之间,以在负压下对油基岩屑进行热脱附和用过热除氧水蒸汽进行汽提吸附；反应器单元内的温度达到278℃时,进入恒温阶段并持续60min,且使所述反应器单元内的温度维持在276℃至285℃之间。该方法,在负压下同时进行热脱附和汽提吸附,提高了回收率和回收质量,使得回收油可以再次用作配置钻井液的基础油,且工艺过程具有低温、低负压的优点。(The application relates to a method for recovering base oil from oil-based rock debris, which comprises a feeding stage, a heating stage, a constant temperature stage and a cooling stage; in the temperature rise stage and the constant temperature stage, stirring the oil-based rock debris at a stirring speed of 150rpm, and maintaining the pressure of a reaction system between-0.042 MPa and-0.047 MPa so as to perform thermal desorption on the oil-based rock debris under negative pressure and perform stripping adsorption by using superheated deoxygenated water vapor; when the temperature in the reactor unit reached 278 ℃, a thermostatting phase was entered and continued for 60min, and the temperature in the reactor unit was maintained between 276 ℃ and 285 ℃. The method simultaneously performs thermal desorption and stripping adsorption under negative pressure, improves the recovery rate and the recovery quality, enables the recovered oil to be reused as base oil for preparing the drilling fluid, and has the advantages of low temperature and low negative pressure in the process.)

1. A method of recovering base oil from oil-based cuttings, comprising: a feeding stage, a heating stage, a constant temperature stage and a cooling stage; wherein the content of the first and second substances,

placing oil-based cuttings in a reactor unit during the feed phase; after the feeding stage is finished, pumping the pressure of the reaction system to-0.04 MPa, maintaining the pressure at-0.04 MPa, and entering the temperature rising stage;

in the temperature rising stage and the constant temperature stage, stirring the oil-based rock debris at a stirring speed of 150rpm, and maintaining the pressure of a reaction system between-0.042 MPa and-0.047 MPa to perform thermal desorption and stripping adsorption on the oil-based rock debris under negative pressure;

in the temperature rise stage, when the temperature in the reactor unit reaches 120 ℃, introducing superheated deoxygenation steam into the reactor unit to perform steam stripping adsorption on the oil-based rock debris and provide an oxygen-insulated protective environment for thermal desorption, wherein the temperature of the superheated deoxygenation steam is between 120 ℃ and 150 ℃; entering the constant temperature stage when the temperature in the reactor unit reaches 278 ℃; wherein the thermostatting phase lasts 60min and the temperature inside the reactor unit is maintained between 276 ℃ and 285 ℃;

in the cooling stage, the heating of the reactor unit is finished, and the reactor unit is cooled to normal temperature; and after the reactor unit is cooled to a temperature below 180 ℃, introducing air into the reactor unit, stopping negative pressure suction to recover the pressure of the reaction system to normal pressure, and stopping stirring.

2. The method of recovering base oil from oil-based cuttings according to claim 1, wherein in the warming stage and the constant temperature stage, the pressure of the reaction system is maintained at-0.045 MPa.

3. The method of recovering base oil from oil-based cuttings of claim 1, wherein the constant temperature stage maintains a temperature within the reactor unit of 280 ℃.

4. The method of recovering base oil from oil-based rock debris of claim 1, wherein the oil-based rock debris has an oil-containing mass of between 5% and 25% and a water-containing mass of between 0% and 5%.

5. The method of recovering a base oil from oil-based cuttings of claim 1, wherein the base oil is # 3 technical white oil.

6. The method of recovering base oil from oil-based cuttings according to claim 1, wherein the oil-based cuttings inside the reactor unit are heated by an electric heating jacket in the warming stage and the constant temperature stage.

7. The method of claim 1, wherein the mixed gas in the reactor unit is sucked into a condensing unit for condensation by a negative pressure generated by a negative pressure unit, and the mixed liquid condensed by the condensing unit is sucked into the buffer unit for storage.

Technical Field

The application relates to the technical field of oil-based rock debris treatment, in particular to a method for recovering base oil from oil-based rock debris.

Background

Oil-based drilling fluids are also known as oil-based muds. It includes water-in-oil emulsified drilling fluid using oil as continuous phase, water (volume content can be up to 50%) as dispersed phase and emulsifier as stabilizing agent and drilling fluid prepared from diesel oil, oxidized asphalt, organic acid, alkali and other chemical agents. Compared with water-based drilling fluid, the oil-based drilling fluid has the advantages of high temperature resistance, salt and calcium corrosion resistance, contribution to well wall stability, good lubricity, small damage to oil-gas layers and the like. Because the above advantages are commonly used for exploration and development of shale gas or oil and gas resources under other complex geological conditions, the cuttings (drill cuttings) generated in the development process can be attached to part of the oil-based drilling fluid and reversely discharged to the ground. With the large-scale development of shale gas, the oil-based cuttings generation amount is increased, and the shale gas development single well generates about 300m³Oil-based cuttings can produce over 200 million tons of waste drill cuttings per year. The oil-based rock debris is a dangerous solid waste, is solid waste which is formed by firmly bonding petroleum hydrocarbon, colloid, asphaltene, rock debris, an inorganic flocculating constituent, an organic flocculating constituent, water, other organic matters and inorganic matters, has the oil content of about 5-25 percent (mass ratio), has higher recovery value and the water content of 0-5 percent, and cannot be directly discharged. Oil-based rock debris needs to be subjected to advanced treatment, the oil content of the oil-based rock debris is reduced, base oil is recovered, and the pollution risk is eliminated.

Disclosure of Invention

To solve the above technical problem or at least partially solve the above technical problem, the present application provides a method of recovering base oil from oil-based cuttings.

The application provides a method for recovering base oil from oil-based rock debris, which comprises the following steps: a feeding stage, a heating stage, a constant temperature stage and a cooling stage; wherein the content of the first and second substances,

in the feed phase, oil-based cuttings are placed in a reactor unit; after the feeding stage is finished, pumping the pressure of the reaction system to-0.04 MPa, maintaining the pressure at-0.04 MPa, and entering a temperature rising stage;

in the temperature rising stage and the constant temperature stage, stirring the oil-based rock debris at a stirring speed of 150rpm, and maintaining the pressure of a reaction system between-0.042 MPa and-0.047 MPa to perform thermal desorption and stripping adsorption on the oil-based rock debris under negative pressure;

in the temperature rise stage, when the temperature in the reactor unit reaches 120 ℃, introducing superheated deoxygenation steam into the reactor unit to perform steam stripping adsorption on the oil-based rock debris and provide an oxygen-insulated protective environment for thermal desorption, wherein the temperature of the superheated deoxygenation steam is between 120 ℃ and 150 ℃; when the temperature in the reactor unit reaches 278 ℃, entering a constant temperature stage; wherein the constant temperature stage lasts for 60min and the temperature in the reactor unit is maintained between 276 ℃ and 285 ℃;

in the cooling stage, the heating of the reactor unit is finished, and the reactor unit is cooled to the normal temperature; and after the reactor unit is cooled to below 180 ℃, introducing air into the reactor unit, stopping negative pressure suction to recover the pressure of the reaction system to normal pressure, and stopping stirring.

In certain embodiments, the pressure of the reaction system is maintained at-0.045 MPa during the temperature-raising stage and the constant-temperature stage.

In certain embodiments, the isothermal stage maintains the temperature within the reactor unit at 280 ℃.

In certain embodiments, the oil-based cuttings have an oil-containing mass between 5% and 25% and a water-containing mass between 0% and 5%.

In certain embodiments, the base oil is # 3 technical white oil.

In certain embodiments, the oil-based cuttings within the reactor unit are heated by an electrical heating jacket during the warm-up phase and the constant temperature phase.

In some embodiments, at the buffer unit, the negative pressure generated by the negative pressure unit draws the mixed gas in the reactor unit into the condensing unit for condensation, and draws the mixed liquid obtained by condensation of the condensing unit into the buffer unit for storage.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

according to the method provided by the embodiment of the application, thermal desorption and stripping adsorption are simultaneously carried out under negative pressure, the recovery rate and the recovery quality are improved, the recovered oil can be used as the base oil for preparing the drilling fluid again, and the process has the advantages of low temperature and low negative pressure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

FIG. 1 is a schematic diagram illustrating the structure of one embodiment of a system for recovering base oil from oil-based cuttings as provided in an example of the present application;

FIG. 2 is a hardware schematic diagram of one embodiment of a control system for recovering base oil from oil-based cuttings as provided in an example of the present application;

FIG. 3 is a flow chart of one embodiment of a method for recovering base oil from oil-based cuttings provided in an example of the present application; and

FIG. 4 is a chromatogram of 3# technical white oil and recycled oil provided in the examples of the present application.

Symbolic illustrations in the drawings:

steam generation unit 100: the system comprises a steam generator 101, a pressure gauge 1, a pressure measuring element 2, a liquid level meter 3, a liquid discharge valve 4, a water supply tank 5, a liquid supply pump 6, a steam output valve 7, a thermal oxygen removal valve 8, a steam conveying pipeline 9 with a pipeline heating belt and a steam flowmeter 10;

the reactor unit 200: the system comprises a reactor 201, a power motor 11, a transmission belt 12, a rotating speed measuring ring 13, a temperature sensor 14, an explosion-proof safety valve 15, a vacuum pressure gauge 16, a steam flowmeter 17, a steam injection end 18, an electric heating jacket 19, an output end 20, a stirrer interface 21, a stirrer 22, a power motor control device 111 and a heating control device 119;

the condensing unit 300: a condenser coil 28 and a cooling water tank 29;

the cache unit 400: a pressure release valve 30, a pressure gauge 31, an injection end 32, an output end 33 and a liquid discharge port 34;

the negative pressure unit 500: a vacuum pump 35, an exhaust gas treatment device 36, and a vacuum pump control device 351;

the control system 600: a timer 23, a rotation speed display 24, a heating temperature control board 25, a stirring speed control knob 26, a heating control knob 27, a memory 601, a processor 602, and a communication device 603.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the following description, suffixes such as "module", "component", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no specific meaning in itself. Thus, "module", "component" or "unit" may be used mixedly.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "first", "second", "third", etc. are used only for distinguishing the description, and are not intended to indicate or imply relative importance.

The terms "upper", "lower", "left", "right", "inner", "outer", and the like, refer to orientations or positional relationships based on orientations or positional relationships illustrated in the drawings or orientations and positional relationships that are conventionally used in the practice of the products of the present invention, and are used for convenience in describing and simplifying the invention, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the invention.

Furthermore, the terms "vertical" and the like do not require absolute perpendicularity between the components, but may be slightly inclined. Such as "vertical" merely means that the direction is relatively more vertical and does not mean that the structure must be perfectly vertical, but may be slightly inclined.

In the description of the present invention, it is also to be noted that the terms "disposed," "mounted," "connected," and the like are to be construed broadly unless otherwise specifically stated or limited. For example, the connection can be fixed, detachable or integrated; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The system for recovering the base oil from the oil-based rock debris provided in the embodiment of the invention can comprise: the system comprises a steam generation unit, a reactor unit, a condensation unit, a buffer unit, a negative pressure unit, a control system, a static storage separation tank, a power supply and the like.

Referring to fig. 1, which is a schematic structural diagram of a system for recovering base oil from oil-based rock debris according to various embodiments of the present disclosure, a steam generation unit 100, a reactor unit 200, a condensation unit 300, a buffer unit 400, a negative pressure unit 500, and a control system 600 are provided. Wherein, the steam generating unit 100 is used for generating superheated deoxygenated water steam to be used as an anaerobic protective environment for stripping adsorption and providing thermal desorption. And the reactor unit 200 is in air-tight communication with the steam generation unit 100 and is used for carrying out steam stripping adsorption and thermal desorption on the oil-based rock debris under the negative pressure condition. And the condensation unit 300 is communicated with the reactor unit 200 in an airtight manner and is used for condensing the mixed gas in the reactor unit 200 to obtain a mixed liquid. And the buffer unit 400 is in air-tight communication with the condensing unit 300 and is used for storing the mixed liquid obtained by condensing in the condensing unit 300. And the negative pressure unit 500 is used for generating negative pressure so that the reactor unit 200 can perform stripping adsorption and thermal desorption on the oil-based rock debris under the negative pressure condition. A control system 600 for controlling a process for recovering base oil from oil-based cuttings.

The various components of the system for recovering base oil from oil-based cuttings are described in detail below with reference to fig. 1.

The reactor unit 200 has a reactor 201, a steam injection end 18, an output end 20, an agitator interface 22, a temperature sensor 14, and an electrical heating jacket 19. The reactor 201 contains oil-based cuttings.

The steam injection end 18 of the reactor unit 200 communicates with the steam generation unit 100. The steam generation unit 100 injects steam, which is superheated deoxygenated water vapor generated by heating deoxygenated water, into the reactor 201. A steam flow meter 10 for measuring the flow rate of the injected steam is provided between the steam generation unit 100 and the steam injection end 18.

The output 20 of the reactor unit 200 is in communication with a condensing unit 300. The condensing unit 300 serves to condense the mixed gas of the reactor 201. The mixed gas comprises oil phase steam and water phase steam. An explosion-proof safety valve 15, a steam flow meter 17 and a vacuum pressure gauge 16 are arranged between the condensing unit 300 and the output end 20.

The stirrer connector 21 is used for installing a stirrer 22 positioned at the upper part of the reactor unit 200, and the stirrer connector 21 is used for connecting different types of stirrers 22. The stirrer 22 is provided with a driving belt 12, a rotating speed measuring ring 13 and a magnetic stirrer interface. The drive belt 12 of the agitator 22 is connected to a power motor 11. The power motor 11 is connected to the control system 600. The rotational speed measuring ring 13 of the stirrer 22 is connected with the control system 600. In certain embodiments, stirrer 22 is a magnetic stirrer.

A temperature sensor 14 is installed at the upper portion of the reactor unit 200, and the temperature sensor 14 is connected to the control system 600. An electric heating jacket 19 is arranged on the outer wall of the reactor 201, and the electric heating jacket 19 is connected with a control system 600.

The steam generation unit 100 has a steam generator 101, a thermal deoxygenation valve 8, a steam delivery line 9 with a line heating tape, a pressure gauge 1, a steam flow meter 10, a level gauge 3, a water supply tank 5, and a liquid supply pump 6.

The steam generator 101 has an inlet end, an outlet end and a drain outlet. The liquid inlet end is connected with a liquid supply pump 6, and the liquid supply pump is connected with a water supply tank 5. The output end is connected with the thermal oxygen removal valve 8, and the thermal oxygen removal valve 8 is used for discharging oxygen and water vapor generated by primarily heating water in the steam generator 101 so as to achieve the purpose of removing oxygen from the water vapor. The steam delivery line 9 is connected to the thermal deoxygenation valve 8, and the steam delivery line 9 delivers the superheated deoxygenated water vapor generated by the steam generator 101 to the reactor unit 200.

The line heating tape is installed to be wound around the steam delivery line 9, and the line heating tape keeps warm for steam flowing through the steam delivery line 9. A steam flow meter 10 is mounted on the steam delivery line 9, the steam flow meter 10 being used to measure the amount of steam output by the steam generator 101. The pressure gauge 1 is arranged on the steam generator 101, and the pressure gauge 1 is connected with the output end of the steam generator 101.

A pressure measuring element 2 is arranged between the control system 600 and the output end of the steam generator 101; the control system 600 controls the heating system of the steam generator 101 to be turned on and off according to the real-time pressure at the output of the steam generator 101.

The condensing unit 300 has a condensing coil 28 and a cooling water tank 29, the condensing coil 28 is disposed in the cooling water tank 29, and the cooling water in the cooling water tank 29 condenses the mixed steam flowing through the condensing coil 28. Condenser coil 28 may comprise a 304 stainless steel 6mm inside diameter 3m condenser coil (5 cm overall coil diameter), a 304 stainless steel 6mm inside diameter 5m condenser coil (10 cm overall coil diameter). In some embodiments, a 304 stainless steel 3m condensing coil with an inner diameter of 6mm and a 304 stainless steel 5m condensing coil with an inner diameter of 6mm are connected in parallel, one end of the condensing coil is connected to the reactor unit 200, and the other end of the condensing coil is connected to the buffer unit 400.

The buffer unit 400 is a vertical gas tank having an injection port 32, an output port 33, a pressure relief valve 30, a liquid discharge port 34, and a pressure gauge 31. The injection end 32 of the buffer unit 400 is connected with the condensing unit 300, and the output end 33 of the buffer unit is connected with the negative pressure unit 500. The pressure relief valve 30 is installed at the top end of the vertical gas storage tank, and the pressure relief valve 30 is used for relieving the overhigh pressure in the vertical gas storage tank. The pressure gauge 31 is arranged in the middle of the vertical gas storage tank, and the pressure gauge 31 is connected with the vertical gas storage tank and used for displaying real-time pressure in the vertical gas storage tank. The liquid outlet 34 is located at the bottom of the vertical gas tank, and the liquid outlet 34 is used for discharging the mixed liquid from the condensing unit 300 buffered in the vertical gas tank.

The negative pressure unit 500 comprises a tail gas treatment device 36 and a vacuum pump 35; the input end of the negative pressure unit 500 is connected with the cache unit 400, the output end of the negative pressure unit 500 is connected with the tail gas treatment device 36, and the tail gas treatment device 36 is composed of an air filter element, activated carbon and oil absorption cotton.

In certain embodiments, the control system 600 is an electronic numerical control box having a heating control knob 27, a stirring speed control knob 26, a heating temperature control panel 25, a rotational speed display 24, and a timer 23. A heating control knob 27 for controlling the switch for heating the electric heating jacket 19. And a stirring speed control knob 26 for controlling the rotation speed of the power motor 11. A heating temperature control plate 25 for adjusting the heating temperature of the electric heating jacket 19. And the rotating speed display 24 is used for displaying the real-time rotating speed of the stirrer 22 measured by the rotating speed measuring ring 13. And a timer 23 for displaying the reaction time.

In other embodiments, the control system 600 includes: a memory, a processor, and a computer program stored on the memory and executable on the processor; the computer program when executed by the processor implements the steps of the method of recovering base oil from oil-based cuttings. Referring to fig. 2, a block diagram of a system for recovering base oil from oil-based cuttings is shown, and a control system as shown in fig. 2 will be described with reference to fig. 1.

The control system 600 may comprise various types of computer equipment, as shown in fig. 2, the control system 600 comprising a processor 602, a memory 601 and a communication means 603. The memory 601 stores data, files and computer programs. The communication device 603 may include various types of communication interfaces and communication protocols to communicate with the reactor unit 100, the negative pressure unit 500, and the steam generation unit 100 to receive detection data of various types of sensors and to send control instructions to various types of control devices.

Referring to fig. 1 and 2, the reactor unit 200 includes a tachometer ring 13, a temperature sensor 14, a power motor control device 111, a heating control device 119, and the like. Referring to fig. 1, the tachometer ring 13 is used to detect the rotation speed of the power motor 11, and the power motor control device 111 is used to adjust the rotation speed of the power motor 11 according to the control command, but is not limited thereto. The temperature sensor 14 is used for detecting the reaction temperature of the reactor unit 200, and the heating control device 119 is used for controlling the heating temperature according to the control instruction of the control system 600 so that the reaction temperature of the reactor unit 200 is at a predetermined value.

Referring to fig. 1 and 2, the negative pressure unit 500 includes a vacuum pump control device 351 for controlling vacuum pumping by the vacuum pump according to a control command of the control system 600 so that the reaction pressure of the reactor unit 200 is within a preset range.

In addition, the control system 600 can communicate with the steam generating unit 100 shown in fig. 1 to control the steam generating unit 100 to generate the required superheated oxygen-removing steam, and the control includes, but is not limited to, a switch, a temperature of the superheated oxygen-removing steam, a flow rate of the superheated oxygen-removing steam, and so on, which will not be described in detail in this embodiment.

The control system 600 may send control commands to the various valve devices shown in fig. 1 to control the opening or closing of the valve devices and the degree of opening of the valve devices, thereby controlling the flow of gas or liquid through the valves.

Computer programs stored on the memory 601 of the control system 600 and executable on the processor 602 include: a control device for recovering base oil from oil-based rock debris realizes a method for recovering base oil from oil-based rock debris, and the method comprises a temperature rise step, a constant temperature step and a cooling step.

After the oil-based rock debris is placed in the reactor 201, an instruction is sent to the vacuum pump control device 351 to control the negative pressure unit 600 to pump the pressure of the reaction system to-0.04 Mpa, and then the temperature is raised. In some embodiments, after the pressure of the reaction system is pumped to-0.04 MPa, the temperature raising step may be performed after the pressure is maintained for a predetermined time.

In the temperature raising step and the constant temperature step, a command is sent to the power motor control device 111 to turn on the stirrer 22 and control the stirrer 22 to stir the oil-based cuttings at a stirring speed of 150rpm, a command is sent to the vacuum pump control device 351 to turn on the vacuum pumping, and the negative pressure unit 600 is controlled and the pressure of the reaction system is maintained between-0.042 MPa and-0.047 MPa to thermally desorb and strip the oil-based cuttings under negative pressure.

In the temperature raising step, an instruction is sent to the heating control device 119 to start heating, and when the temperature sensor 14 detects that the temperature in the reactor 201 reaches 120 ℃, the steam generation unit 100 is controlled to start introducing the superheated deoxygenated steam into the reactor to strip and adsorb the oil-based rock debris and provide an oxygen insulation protection environment required by thermal desorption, wherein the temperature of the superheated deoxygenated steam is between 120 ℃ and 150 ℃. When the temperature in the reactor 201 reaches 278 ℃ detected by the temperature sensor 14, entering a constant temperature step; wherein the constant temperature step lasts for 60min, and the temperature in the reactor is controlled to be maintained between 276 ℃ and 285 ℃ by a heating control device 119.

And after the constant temperature step lasts for 60min, entering a cooling step. In the cooling step, the heating control device 119 is controlled to stop heating the reactor 201, and the reactor 201 is cooled to normal temperature; wherein, after the cooling step is carried out for 10min, the introduction of superheated deoxygenated steam into the reactor 201 is finished, when the temperature of the reactor is detected to be cooled to below 180 ℃ by the temperature sensor 14, the introduction of air into the reactor 201 is controlled, the negative pressure unit 500 is controlled to stop negative pressure suction to recover the pressure of the reaction system to normal pressure, and the stirrer is controlled to stop stirring. And controls the negative pressure unit 600 to stop the negative pressure suction to restore the pressure of the reaction system to the normal pressure, and sends an instruction to the power motor control device 111 to control the stirrer 22 to stop stirring.

Referring to fig. 3, in certain embodiments, a method of recovering base oil from oil-based cuttings includes: a feed stage S300, a warming stage S302, a constant temperature stage S304, and a cooling stage S306. The method may be controlled automatically by the control system as described in fig. 2 or may be operated partially manually by the control system 600 as shown in fig. 1.

In the present embodiment, in the feeding stage S300, oil-based cuttings are placed in the reactor unit 200; after the feeding stage S300 is completed, the pressure of the reaction system is pumped to-0.04 MPa by the negative pressure unit 500 and maintained at-0.04 MPa for a certain period of time (e.g., 10 minutes), and then the temperature is raised in the temperature raising stage S302.

In the temperature rising stage S302 and the constant temperature stage S304, the oil-based rock debris is stirred at the stirring speed of 150rpm, and the pressure of the reaction system is maintained between-0.042 MPa and-0.047 MPa, so that the oil-based rock debris is subjected to thermal desorption and stripping adsorption under negative pressure.

In the temperature rise stage S302, when the temperature in the reactor unit reaches 120 ℃, introducing superheated deoxygenation steam into the reactor unit to perform steam stripping adsorption on the oil-based rock debris and provide an oxygen-insulated protective environment for thermal desorption, wherein the temperature of the superheated deoxygenation steam is between 120 ℃ and 150 ℃; when the temperature in the reactor unit reaches 278 ℃, entering an S304 constant temperature stage; wherein the S304 isothermal stage lasts 60min and the temperature inside the reactor unit is maintained between 276 ℃ and 285 ℃.

In the cooling stage S306, the heating of the reactor unit is terminated, and the reactor unit is cooled to normal temperature. And after entering the cooling stage S306 for ten minutes, finishing introducing superheated deoxygenated water vapor into the reactor unit, after the temperature of the reactor unit is cooled to be below 180 ℃, introducing air into the reactor unit, stopping negative pressure suction to recover the pressure of the reaction system to normal pressure, and stopping stirring.

After the cooling stage S306 is completed, the solid phase in the reactor unit is removed, the liquid is removed from the buffer unit, and the oil phase is separated therefrom.

The present invention will be further illustrated by the following specific examples, but the present invention should not be construed as being limited to these examples. In the examples, all parts and percentages are given by weight unless otherwise indicated.

Method for recovering base oil from oil-based rock debris

Example 1

Weighing 945.31g of liquid-containing solid phase produced by a drilling field spin-drying device, adding the 945.31g into a 3L (internal volume) reactor unit, covering a kettle cover according to an operation rule and fastening; connecting a steam pipeline; the exhaust pipeline is connected with the condensing system, the condenser is connected with the vertical gas storage tank, and the vertical gas storage tank is connected with the vacuum pump; the reactor unit heating power supply, the stirrer power supply were connected and a thermometer was inserted.

And opening a vacuum pump, sucking the gas in the vertical gas storage tank, the condenser and the reactor unit, reducing the pressure to-0.040 MPa, and keeping the pressure for 10 minutes without reduction.

Turning on a stirrer on the reactor unit, and adjusting the rotating speed to 150 revolutions; turning on a heating switch of the reactor unit to start heating; reducing the pressure in the reactor unit to-0.045 MPa and maintaining the pressure;

when the temperature in the reactor unit rises to 120 ℃, the water vapor is started to be added, and the adding amount is based on the pressure in the reactor unit of-0.042 to-0.047 MPa.

The temperature in the reactor unit is increased to 278 ℃ and the time is started, and then the temperature is kept between 276 ℃ and 285 ℃ and is maintained for 1 hour.

And (3) closing a heating power supply of the reactor unit, starting cooling, starting to put a small amount of air after the temperature in the reactor unit is reduced to 180 ℃ in order to accelerate the cooling speed until the temperature in the reactor unit is reduced to below 150 ℃, closing the stirrer, and closing the steam generator, the vacuum pump and the power supply main gate.

Cooling the temperature in the reactor unit to normal temperature, opening the reactor unit, and taking out the solid phase; discharging the liquid in the vertical gas storage tank.

After the liquid discharged from the vertical gas tank was left standing for 24 hours, the upper oil was extracted, the solid in the reactor unit was taken, and the results of the detection are shown in table 1.

Table 1 table of parameters and test results of example 1

Serial number	Temperature of	Rotating speed (rotating/minute)	Negative pressure (MPa)	Time (minutes)	Oil content (%)
						1	280	150	-0.045	60	0.01

Example 2

Weighing 783.31g of oil-based detritus under a vibrating screen on a drilling site, adding the weighed detritus into a 3L (internal volume) reactor unit, covering a kettle cover according to an operation rule and fastening; connecting a steam pipeline; the exhaust pipeline is connected with the condensing system, the condenser is connected with the vertical gas storage tank, and the vertical gas storage tank is connected with the vacuum pump; the reactor unit heating power supply, the stirrer power supply were connected and a thermometer was inserted.

And 2, opening the vacuum pump, sucking the gas in the vertical gas storage tank, the condenser and the reactor unit, reducing the pressure to-0.040 MPa, and keeping the pressure for 10 minutes without reduction.

3, opening a stirrer on the reactor unit, and regulating the rotating speed to 150 revolutions; turning on a heating switch of the reactor unit to start heating; the pressure in the reactor unit was reduced to-0.045 MPa and maintained.

And 4, when the temperature in the reactor unit rises to 120 ℃, starting to add the water vapor, wherein the adding amount is based on that the pressure in the reactor unit is between-0.042 and-0.047 MPa.

5, starting the timer when the temperature in the reactor unit rises to 278 ℃, and then keeping the temperature between 276 and 285 ℃ for 1 hour.

And 6, closing the heating power supply of the reactor unit, starting cooling, in order to accelerate the cooling speed, after the temperature in the reactor unit is reduced to 180 ℃, starting to put a small amount of air until the temperature in the reactor unit is reduced to below 150 ℃, closing the stirrer, and closing the steam generator, the vacuum pump and the power supply main gate.

7, reducing the temperature in the reactor unit to normal temperature, opening the reactor unit, and taking out rock debris; discharging the liquid in the vertical gas storage tank.

8, after the liquid discharged from the vertical gas storage tank is static for 24 hours, extracting the upper oil, taking the solid in the reactor unit, and detecting the result as shown in table 2.

Table 2 example 2 table of parameters and test results

Serial number	Temperature of	Rotating speed (rotating/minute)	Negative pressure (MPa)	Time (minutes)	Oil content (%)
						2	280	150	-0.045	60	0.02

Wherein, the oil content calculation formula is as follows: solid phase oil content (%) after thermal desorption ═ measured oil mass/(measured oil mass + measured solid phase mass).

The results show that: the method of reduced pressure distillation is used, reasonable parameters can meet the high standard requirement of harmless treatment, the running cost of equipment is considered, and the parameters of temperature, rotating speed, negative pressure, time and the like are optimized, so that the method can meet the requirement of environmental protection and can generate good economic benefit.

Second, chromatographic analysis of recovered oil and 3# white oil

The chromatographic components obtained by chromatographic analysis of the white oil No. 3 and the recovered oil of this example are shown in Table 3, and the chromatogram is shown in FIG. 4.

TABLE 33 # chromatographic analysis chart for industrial white oil and recovered oil

Referring to table 3 and fig. 4, the # 2 recovered oil is an oil chromatogram obtained at a heating constant temperature of 240 ℃, the # 1 recovered oil is an oil chromatogram obtained at a heating constant temperature of 280 ℃, and the white oil is an oil chromatogram of the # 3 industrial white oil used for preparing the oil-based drilling fluid. Through chromatographic analysis and comparison, the 3# white oil and the recovered oil product have large difference only from n-eicosane to n-hexacosane, and the n-pentacosane and the n-hexacosane are not detected from the 3# white oil. The proportion of n-undecane to n-nonadecane in 3# white oil is 99.19%, the proportion of n-undecane to n-nonadecane in oil products subjected to thermal desorption is 93.66%, and the oil products have basically the same composition.

Third, the performance comparison of the oil base drilling fluid prepared by the recovered oil

A comparison experiment for preparing the oil-based drilling fluid is carried out on the 3# white oil and the recovered oil obtained by the method in the embodiment of the application, the oil-based drilling fluid is prepared according to an oil-based drilling fluid formula with an oil-water ratio of 65:35 and 85:15, whether the recovered oil can be used as base oil for preparing the oil-based drilling fluid in field construction is verified, and experimental data are shown in tables 4 and 5 below.

TABLE 465/353 # white oil and reclaimed oil formulated oil-based drilling fluid performance comparison table

Table 585 oil base drilling fluid performance comparison table for No. 153 white oil and recovered oil configuration

From tables 4 and 5, it can be seen that the properties of the oil-based drilling fluid prepared from the oil recovered by the method of the embodiment of the present application are similar to those of the oil-based drilling fluid prepared from the 3# white oil. The recovered oil product can be used as base oil for preparing oil-based drilling fluid in field construction operation.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.