Drilling fluid degassing efficiency measuring device and method based on multi-stage degassing-index accumulation first effect method

Abstract

The invention discloses a drilling fluid degassing efficiency measuring device and method based on a multi-stage degassing-index accumulation first effect method, and belongs to the field of oil-gas exploration. The device comprises a circulating tank system, a stirring system and a liquid suction pump system, and the circulating tank system at least comprises two circulating tanks and is used for alternately storing and conveying gas-containing drilling fluid; the circulating tank system is discontinuously connected with the stirring system through a first valve group, and is discontinuously connected with the stirring system through a second valve group; an exhaust port of the stirring tank is connected with a chromatographic analyzer through a gas pipeline; the liquid suction pump system comprises a liquid suction pump, and the liquid suction pump is connected with the circulation tank through a fifth valve. The method comprises the following steps: carrying out index curve fitting on multi-stage degassing gas component content data measured by an experiment to determine the total gas content of the drilling fluid; and determining the degassing efficiency of the degasser on the drilling fluid according to the ratio of the gas component of the first degassing to the total gas content. The degassing efficiency of the drilling fluid can be accurately measured, and a basis is provided for accurately evaluating the gas content of a stratum.

Description

Technical Field

[0001] The present invention relates to the field of oil and gas exploration, and particularly to a device and method for measuring the degassing efficiency of drilling fluid based on multi-stage degassing - exponential cumulative first method. Background Art

[0002] In the field of oil exploration, degassing devices are required to degas the drilling fluid. Measuring the degassing efficiency of drilling fluid is a key link in the process of oil drilling, and it is of great significance for accurately evaluating the gas content of the formation and well control risk. During the drilling process, formation gases will dissolve or disperse in the drilling fluid. By measuring the gas content in the drilling fluid, formation gas information can be obtained, providing important data support for geological logging.

[0003] Common degassers are divided into non - quantitative degassers and quantitative degassers according to their continuous degassing displacement. The commonly used quantitative degasser GZG for gas logging has a continuous pumping displacement of drilling fluid of 1500 ml / min, and the rotation speed of the stirring rod in the stirring tank is 1400 r / min.

[0004] However, the existing technologies for measuring the degassing efficiency of drilling fluid still have some problems and deficiencies. First of all, traditional degassing devices usually adopt a single degassing tank design, which cannot achieve continuous degassing, resulting in low degassing efficiency. Secondly, it is difficult for existing technologies to accurately measure the degassing efficiency of drilling fluid under different density, temperature and viscosity conditions, affecting the accuracy of gas logging data. In addition, the existing degassing efficiency calculation methods often ignore the influence of residual gas in the drilling fluid and cannot comprehensively reflect the true gas content of the drilling fluid.

[0005] In particular, there is a lack of a device and method in the existing technology that can achieve multi - stage degassing and accurately measure the degassing efficiency. In practical applications, single - stage degassing often cannot completely remove the gas in the drilling fluid, and multiple degassing is required to obtain more accurate gas content data. However, it is difficult for the existing technology to achieve continuous operation and precise measurement during multi - stage degassing, and there is also a lack of a cumulative calculation method based on multi - stage degassing data, resulting in inaccurate degassing efficiency measurement results and affecting the reliability and on - site applicability of geological logging data.

[0006] Therefore, it is urgent to develop a device and method that can adapt to different properties of drilling fluid, achieve multi - stage continuous degassing and accurately measure the degassing efficiency, so as to improve the accuracy and reliability of gas logging data and provide more reliable technical support for geological logging and well control safety. Summary of the Invention

[0007] In order to solve the problems of complexity and insufficient accuracy existing in the existing methods for measuring the degassing efficiency of drilling fluids, as well as the technical problems that the existing methods cannot adapt to drilling fluids with different densities, temperatures, and viscosities, which affect the accuracy of gas logging data and reduce the reliability and on-site applicability of geological logging data, the present invention provides a device and method for measuring the degassing efficiency of drilling fluids based on multi-stage degassing - exponential cumulative first method.

[0008] The technical solution adopted by the present invention to solve its technical problems is to provide a device for measuring the degassing efficiency of drilling fluids based on multi-stage degassing - exponential cumulative first method, including a stirring tank and a liquid suction pump system. The exhaust port of the stirring tank is connected to a gas pipeline, and the other end of the gas pipeline is connected to the chromatographic analyzer. Further, it includes a circulation tank system. The circulation tank system includes at least two circulation tanks, and the circulation tanks alternately store and transport gas-containing drilling fluids; the stirring system is connected to the circulation tank system through a first valve group and a second valve group; the liquid suction pump system includes a liquid suction pump, and the liquid suction pump is connected to the circulation tank through a fifth valve. The device for measuring the degassing efficiency of drilling fluids is mainly used to measure the degassing efficiency of a drilling fluid degasser for drilling fluids.

[0009] Further, the at least two circulation tanks in the circulation tank system are controlled by a first valve, and alternately input the degassed drilling fluid from the stirring system into one circulation tank. The first valve is arranged between the circulation tanks; the first valve is one of the valves in the first valve group, and the first valve is a three-way valve, and the three-way valve is respectively connected to two circulation tanks and the stirring system.

[0010] Further, the circulation tank system further includes an air inlet, an exhaust port, a stirring tank, and a stirring motor. The drilling fluid input into the circulation tank system is stirred and degassed, and the degassing amount is measured by the chromatograph.

[0011] Further, the second valve group includes a second valve, a sixth valve, and a fifth valve. The second valve is connected between the circulation tanks. Through the control of the second valve, the drilling fluid alternately flows out of the circulation tank and is input into the stirring tank system through the liquid suction pump.

[0012] Further, a temperature sensor is arranged between the second valve and the sixth valve. A heat tracing tape and a heating tape are arranged outside the circulation tank. According to the temperature of the drilling fluid in the pipeline detected by the temperature sensor, the heat tracing tape and the heating tape are controlled to heat, so as to keep the temperature of the fluid in the circulation pipeline constant.

[0013] The present invention also provides a method for measuring the degassing efficiency of drilling fluids based on multi-stage degassing - exponential cumulative first method, including the following steps: Pump liquid from the sample cell (referred to as "return chute" at the drilling site), input it into the stirring tank, adjust the first valve to make the drilling fluid flow into the first circulation tank, start the first degassing process, observe the drilling fluid flowing into the first circulation tank until it is full, and record the gas logging values of each component measured by the chromatograph.

[0014] When the first circulation tank is full, quickly adjust the second valve and the fifth valve to pump liquid from the first circulation tank. At the same time, adjust the first valve to make the liquid flow to the second circulation tank. When the drilling fluid in the first circulation tank in the circulation tank system is pumped out, quickly adjust the second valve to pump liquid from the second circulation tank. At the same time, adjust the first valve to make the liquid flow to the first circulation tank; when the second circulation tank is pumped out, adjust the second valve to pump liquid from the first circulation tank again. At the same time, adjust the first valve to make the liquid flow to the second circulation tank; repeat the process of switching the second and first valves to perform multi-stage degassing of the drilling fluid; when the chromatograph shows that the gas in the drilling fluid is lower than 0.01% or the gas logging value is lower than 1% of the initial value, stop degassing, and open the third valve and the fourth valve to discharge all the drilling fluid in the circulation tank.

[0015] Furthermore, perform exponential curve fitting on the gas component content data of the multi-stage degassing of the drilling fluid measured in the experiment, and determine the total gas content of the drilling fluid based on the exponential fitting data.

[0016] Furthermore, the total gas content is determined by accumulating two parts of data. One part of the data is the degassing volume of N experiments, and the other part of the data is the remaining degassing volume determined by the fitting data after N times.

[0017] Furthermore, determine the degassing efficiency of the drilling fluid by the ratio of the gas components in the first degassing to the total gas content.

[0018] The beneficial effects of the present invention are as follows: Through the alternating pumping and discharging of the circulation tank and the variable-frequency stirring motor, continuous multiple experimental degassing is realized, the law of gas release attenuation is dynamically captured, the static error limit of traditional single degassing is broken through, the accuracy of degassing efficiency measurement is improved, and a basis is provided for accurately evaluating the gas content of the formation; The equipment is made of stainless steel, and by integrating a temperature control system and a variable-frequency liquid pump, it can simulate the performance of drilling fluid under complex working conditions such as drilling fluid density, temperature, and viscosity in real time, enhancing the environmental adaptability, and is especially suitable for applications on offshore platforms and in complex formations; Based on the experimental data, an exponential equation is fitted, a degassing concentration attenuation curve is constructed, and a total gas content formula is derived, solving the problem of extrapolating limited experimental data; After quantifying the degassing efficiency, it provides a standardized calibration basis for gas logging interpretation, enhances the accuracy of logging data, and lays a foundation for horizontal comparison between wells and the interpretation and evaluation of logging data in the later stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, and do not constitute a limitation to the present invention. In the drawings: Figure 1 : Overall design drawing for measuring the degassing efficiency of drilling fluid.

[0020] Figure 2 : Structural layout drawings of the first, second, third, and fourth valves.

[0021] Figure 3 : Structural layout drawings of the fifth and sixth valves.

[0022] Figure 4 : Test results of the first group for Well YL10-6-2.

[0023] Figure 5 : Test results of the second group for Well YL10-6-2.

[0024] Figure 6 : Test results of the third group for Well YL10-6-2.

[0025] Figure 7 : Test results of the third group for Well DF11-2-1d.

[0026] Figure 8 : Test results of the fourth group for Well DF11-2-1d.

[0027] Figure 9 : Test results of the fifth group for Well DF11-2-1d.

[0028] Figure 10 : Test results of the sixth group for Well DF11-2-1d.

[0029] Figure 11 : Test results of the seventh group for Well DF11-2-1d.

[0030] Figure 12 : Test results of the eighth group for Well DF11-2-1d.

[0031] In the figure: 1 - liquid suction pump, 2 - stirring motor, 3 - stirring tank, 4 - air inlet, 5 - exhaust port, 6 - pipeline, 7 - Tank A, 8 - Tank B, 9 - flip cover, 10 - filter screen, 11 - temperature sensor, T1 - first valve, T2 - second valve, T3 - third valve, T4 - fourth valve, T5 - fifth valve, T6 - sixth valve. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Example 1:

[0034] This example provides a device for measuring the degassing efficiency of drilling fluid based on multi-stage degassing - exponential cumulative first method. As shown in Figure 1 , the device includes a stirring tank 3, a liquid suction pump system, a circulation tank system, and a stirring system. The exhaust port 5 of the stirring tank 3 is connected to a gas pipeline, and the other end of the gas pipeline is connected to a chromatograph analyzer. The circulation tank system includes at least two circulation tanks A and B, and the circulation tanks alternately store and transport gas-containing drilling fluid. The stirring system is intermittently connected to the circulation tank system through a first valve group, and the stirring system is intermittently connected to the circulation tank system through a second valve group; the liquid suction pump system includes a liquid suction pump, and the liquid suction pump is connected to the circulation tank through a fifth valve.

[0035] The two circulation tanks A and B in the circulation tank system are controlled by a first valve T1, and alternately input the degassed drilling fluid from the stirring system into one of the circulation tanks. The first valve T1 is set between the circulation tanks. The first valve T1 is a three-way valve, and the three-way valve is respectively connected to the two circulation tanks and the stirring system. The volumes of both of these two circulation tanks A and B are 18L, and the material is stainless steel, which can withstand a pressure of 0.5 MPa. The outer walls of the circulation tanks A and B are both wrapped with a heating tape and a heating belt with a power of 200W. The heating tape and the heating belt are connected to a temperature controller through a temperature sensor 11. When the temperature sensor 11 detects that the temperature of the drilling fluid in the pipeline is lower than the set value, the temperature controller will start the heating tape for heating. Two heat preservation barrels are used to achieve cyclic degassing. The main body of the equipment is made of stainless steel and is suitable for the offshore platform environment. The outer wall of the heat preservation barrel is wound with an explosion-proof heating belt to maintain the mud temperature, and an on-line thermometer is installed at the same time to observe the mud temperature in real time. Flip covers 9 are provided at the upper ends of the circulation tanks A and B. After opening the flip covers 9, the drilling fluid before degassing can be injected into the circulation tanks A and B. The filter screen 10 can remove the impurities in the drilling fluid to avoid the blockage of the pipeline and related valves by the drilling fluid impurities.

[0036] The stirring system includes an air inlet 4, an exhaust port 5, a stirring tank 3, and a stirring motor 2. The drilling fluid input into the circulation tank system is degassed by stirring, and the degassing volume is measured by a chromatograph. The mud pumping displacement is 1.5 liters per minute, and the rotation speed of the stirring tank motor is 1400 revolutions per minute. The second valve group includes a second valve T2, a fifth valve T5, and a sixth valve T6 (as shown in Figure 3As shown, the second valve T2 is connected between the circulation tanks A and B. Through the control of the second valve T2, the drilling fluid alternately flows out from the circulation tanks A and B and is input into the mixing tank system through the suction pump 1. A temperature sensor 11 is provided between the second valve T2 and the fifth valve T5. A heat tracing tape and a heating tape are provided outside the circulation tanks A and B. The heat tracing tape and the heating tape are controlled to heat according to the temperature of the drilling fluid in the pipeline detected by the temperature sensor 11, so as to keep the temperature of the fluid in the circulation pipeline constant. A third valve T3 and a fourth valve T4 are respectively connected to the outer sides of the circulation tanks A and B. When the entire device stops degassing, the third valve T3 and the fourth valve T4 are opened to drain the drilling fluid in the circulation tanks A and B, which is convenient for subsequent cleaning of the circulation tanks A and B.

[0037] The volume of the mixing tank 3 is customized according to the amount of the drilling fluid, and 1.5 L can be selected. The material is also stainless steel and can withstand a pressure of 1 MPa. A mixing motor 2 is provided at the top of the mixing tank 3. The power of the mixing motor 2 is 1.5 kW, and the maximum rotation speed can reach 1500 rpm. The shaft of the mixing motor 2 is connected with a mixing paddle. The mixing paddle is designed with four blades and can form strong turbulence in the mixing tank 3 to promote the precipitation of gas in the drilling fluid.

[0038] An air inlet 4 and an exhaust port 5 are also provided at the top of the mixing tank 3. The air inlet 4 is connected with a gas supplementing system, and nitrogen or air can be introduced into the mixing tank 3 to adjust the pressure in the mixing tank 3. The exhaust port 5 is connected with a gas pipeline, and the other end of the gas pipeline is connected with a chromatograph. The chromatograph adopts a gas chromatograph and can qualitatively and quantitatively analyze the gas components separated from the drilling fluid, and the detection accuracy can reach 0.0001%.

[0039] The first valve T1 can be a manual three-way valve or an electric three-way valve. When it is a manual three-way valve, it is manually switched through the judgment of the worker; when it is an electric three-way valve, remote control can be realized through the control system, and the switching time is less than 1 second. The second valve T2 is also a manual three-way valve or an electric three-way valve and has the same performance parameters.

[0040] The suction pump 1 is a diaphragm pump. The diaphragm pump is used to pump the mud. The pump speed (displacement) is adjusted by a variable frequency pump, the mixing speed is adjusted by a variable frequency motor, the heat tracing tape maintains the temperature of the mud, and the heating tape can heat the mud. The degassing efficiency is measured by degassing the same sample multiple times, and then the true gas content in the mud is restored through data correction, so as to improve the gas component recognition and the accuracy of gas logging interpretation.

[0041] When the device is tested at the drilling site, the drilling fluid is selected to be pumped from the return tank at the drilling site. The fifth valve T5 is used to directly suck the drilling fluid from the on-site return tank, and under the push of the liquid suction pump system, the drilling fluid enters the mixing tank 3 for the first degassing. After the first degassing, the drilling fluid flows into the circulation tank (A / B) under the action of gravitational potential energy. Therefore, in this solution, the position of the mixing tank should be higher than that of the circulation tank (A / B), especially the height of the liquid outlet of the mixing tank 3 should be higher than the height of the liquid inlet of the circulation tank (A / B). Then, driven by the liquid suction pump system, the liquid is pumped from the circulation tank (A / B) again for the second, third, fourth, and fifth degassing; when the device is not tested at the drilling site, the liquid is pumped from the circulation tank (A / B), and the drilling fluid in the circulation tank (A / B) is directly injected into the circulation tank (A / B) through the flip cover 9 and the filter screen 10 as described above.

[0042] T6 is a manual three-way valve, and an electric device can also be selected to measure the flow rate of the drilling fluid after being pressurized by the liquid suction pump 1. When the flow rate in the pipeline exceeds the threshold, the power of the liquid suction pump 1 is reduced, and when the flow rate in the pipeline is lower than the threshold, the power of the liquid suction pump 1 is increased. In this solution, the flow rate of the pump is adjusted manually, and an electric method can also be further adopted for automatic control.

[0043] Embodiment 2: This embodiment provides a method for measuring the degassing efficiency of drilling fluid based on multi-stage degassing - exponential cumulative first method. The measuring device described in Embodiment 1 is used, and the measuring steps of the measuring device include the following content.

[0044] Step 1: Equipment preparation and connection Power connection: Ensure that the device has been correctly connected to the 220V power supply, and check whether the connection of the power cord is firm. Air pipeline connection: Connect one end of the air pipeline to the exhaust port 5 of the mixing tank 3 of the device, and the other end to the sample inlet of the chromatograph analyzer. Ensure that the connection is well sealed to prevent gas leakage.

[0045] Step 2: Equipment parameter adjustment Pump displacement adjustment: Adjust the displacement of the liquid suction pump 1 to 1500 ml / min (Adjustment method: Turn on the liquid suction pump, suck the drilling fluid from the T5 valve, discharge it from the T6 valve and use a stopwatch and measuring cup to measure. Rotate the flow rate adjustment knob on the liquid suction pump body until the measured value is 1500 ml / min). This can be set through the control panel of the variable frequency pump. Stirring speed adjustment: Adjust the stirring speed of the stirring rod to 1400 revolutions per minute (adjusted by the knob inside the explosion-proof box as Figure 2 shown). This can be set through the control panel of the variable frequency motor.

[0046] Step 3: Start cyclic degassing Adjust the T5 valve to pump liquid from the sample pool (reflux tank at the drilling site), adjust the T5 valve to flow towards the mixing tank 3, and adjust the T1 valve to flow towards tank A 7; turn on the main power switch, the liquid pumping pump switch, and the heat tracing tape switch in sequence, and the measuring device starts the first degassing; observe the drilling fluid flowing into tank A until it is full, and record the gas logging values of each component measured by the chromatograph; If it is not suitable to pump liquid on-site, the liquid in the sample pool, i.e., the gas-bearing drilling fluid, can be directly poured into tank A of the circulation tank.

[0047] Subsequently, start the equipment: turn on the main power switch, the liquid pumping pump switch, and the heat tracing tape switch in sequence. Start the circulating degassing process.

[0048] Step 4: Gas analysis Chromatograph analysis: Use the chromatograph to analyze the degassed gas and record the analysis results. This will help determine the gas content and composition in the mud.

[0049] Step 5: Circulation tank switching From tank A to tank B: When the drilling fluid in tank A is pumped out, quickly adjust the T2 valve to pump liquid from tank B of the circulation tank, and at the same time adjust the T1 valve to flow towards tank A. This will start pumping the mud from tank B for degassing. From tank B to tank A: When the drilling fluid in tank B is pumped out, quickly adjust the T2 valve to pump liquid from tank A of the circulation tank, and at the same time adjust the T1 valve to flow towards tank B. This will restart pumping the mud from tank A for degassing.

[0050] Step 6: Repeat the degassing process Repeat steps 5 to 6: Continue to repeat the above steps until the gas detector shows that the gas content in the drilling fluid drops below 0.01%, or the gas logging value is less than 1% of the initial value. This indicates that the gas content in the drilling fluid has been reduced to a relatively low level.

[0051] Step 7: Clean the equipment Discharge the mud: After the test, open the T3 and T4 valves to discharge the drilling fluid in tanks A and B. Clean the tank body and pipeline: Pour clean water to clean the residual drilling fluid in tanks A and B and the pipeline respectively. Ensure that all components are cleaned to prevent cross-contamination.

[0052] Perform exponential curve fitting on the gas component content data of the multi-stage degassing of the drilling fluid measured in the experiment. The fitting curve is shown in Figures 4 - 12 . At the same time, determine the total gas content of the drilling fluid based on the exponentially fitted data. According to the degassing efficiency experiment, define the measured values of a certain gas component for each degassing in the experiment as a1, a2, a3... an, and the value of the xth degassing of the experimental data exponentially curve fitting as. The sum of the measured value of a certain gas component calculated from the measured value of the degassing experiment plus the subsequent value based on the exponentially curve fitting is the total gas content S of this component in the drilling fluid a-y Total gas content calculation: (N = number of experiments); The formula for the degassing efficiency of the drilling fluid of this component: . Accurately evaluate the proportion of the first degassing to provide a standardized calibration basis for gas logging interpretation.

[0053] Perform exponential curve fitting on the gas component content data of the multi-stage degassing of the drilling fluid measured in the experiment. The fitting curve is shown in Figures 4 - 12 . At the same time, determine the total gas content of the drilling fluid based on the exponentially fitted data. According to the degassing efficiency experiment, define the measured values of a certain gas component for each degassing in the experiment as a1, a2, a3... an, and the x-th degassing value of the exponential curve fitting of the experimental data as. The sum of a certain gas component calculated by adding the measured value of the degassing experiment and the subsequent value based on the exponential curve fitting is the total gas content S of this component in the drilling fluid a-y . Calculation of total gas content: (N = number of experiments); The formula for the degassing efficiency of the drilling fluid of this component: . Accurately evaluate the proportion of the first degassing to provide a standardized calibration basis for gas logging interpretation.

[0054] This experiment was carried out 9 times in two wells, namely Well YC36-2-1 and Well DF11-2-1d in a certain oilfield. The experimental results are shown in Table 1, Figures 4 - 12 as shown. From Table 1, Figures 4 - 12 it can be seen that the degassing efficiency curves obtained from each well are basically the same and have a common rule, that is, as the number of carbon atoms increases, the degassing efficiency gradually decreases. This shows that the larger the number of carbon atoms in hydrocarbon gases, the stronger the ability to adsorb in the drilling fluid, the more difficult it is to remove from the drilling fluid, and the lower the degassing efficiency, which is consistent with the theory. The degassing efficiency of the drilling fluid of the present invention is of great significance for discovering, interpreting, and evaluating oil and gas layers. During the logging process, this value can be used to perform real-time calibration on the gas logging value, enhance the accuracy of logging data, and lay a foundation for horizontal comparison between wells and the subsequent interpretation and evaluation of logging data.

[0055] Table 1. Degassing efficiency of each gas component in different wells

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0057] Other embodiments of the present application will be readily contemplated by those skilled in the art upon consideration of the specification and practice of the application disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include the common general knowledge or conventional technical means in the technical field disclosed in the present application. The specification and examples are only regarded as exemplary, and the true scope of the present application is pointed out by the claims.

Claims

1. A device for measuring the degassing efficiency of drilling fluid based on a multi-stage degassing-exponential cumulative first method, comprising a stirring system and a liquid suction pump system. The stirring system includes a stirring tank (3), and an exhaust port (5) of the stirring tank (3) is connected to a gas pipeline, and the other end of the gas pipeline is connected to a chromatographic analyzer, characterized in that, Further includes a circulating tank system, the circulating tank system includes at least two circulating tanks (A, B), and the circulating tanks alternately store and convey the gas-containing drilling fluid; the stirring system and the circulating tank system are connected through a first valve group and a second valve group; the liquid suction pump system includes a liquid suction pump, and the liquid suction pump is connected to the circulating tanks (A, B) through a fifth valve.

2. The drilling fluid degassing efficiency measuring device based on the multi-stage degassing-exponential cumulative first method according to claim 1, characterized in that The at least two circulating tanks (A, B) in the circulating tank system are controlled by a first valve (T1), and alternately input the degassed drilling fluid from the stirring system into the circulating tanks, and the first valve (T1) is arranged between the circulating tanks; The first valve (T1) is a three-way valve, and the three-way valve is respectively connected to two circulating tanks and the stirring system.

3. The device for measuring the degassing efficiency of drilling fluid based on the multi-stage degassing-exponential cumulative first method according to claim 2, wherein The first valve (T1) is one of the valves in the first valve group.

4. The device for measuring the degassing efficiency of drilling fluid based on the multi-stage degassing-exponential cumulative first method according to claim 2, characterized in that, The stirring system further includes an air inlet (4), an exhaust port (5) and a stirring motor (2), and the drilling fluid input into the circulating tank system is stirred and degassed, and the degassing amount is measured by the chromatograph.

5. The drilling fluid degassing efficiency measuring device based on the multi-stage degassing-exponential cumulative first method according to claim 1, characterized in that, The second valve group includes a second valve (T2), a fifth valve (T5) and a sixth valve (T6), the second valve (T2) is connected between the circulating tanks (A, B), and through the control of the second valve (T2), the drilling fluid alternately flows out from the circulating tanks (A, B) and is input into the stirring system through the liquid suction pump (1).

6. The drilling fluid degassing efficiency measuring device based on the multi-stage degassing-exponential cumulative first method according to claim 5, characterized in that, A temperature sensor (11) is arranged between the second valve (T2) and the fifth valve (T5), and a heat tracing belt is arranged outside the circulating tanks (A, B), and the heat tracing belt heating is controlled according to the temperature of the drilling fluid in the pipeline detected by the temperature sensor (11) to keep the temperature of the fluid in the circulating pipeline constant.

7. A method for measuring the degassing efficiency of drilling fluid based on a multi-stage degassing-exponential cumulative first method, characterized in that, Using the measuring device according to any one of claims 1 - 6, includes the following steps: S1 Pump liquid from the return tank at the drilling site, input it into the stirring tank, adjust the first valve to make the drilling fluid flow into the first circulating tank, start stirring and degassing, observe the drilling fluid flowing into the first circulating tank until it is full, and record the gas measurement values of each component measured by the chromatograph; or directly fill the sample or the sample taken from the return tank at the drilling site into the first circulating tank until it is full, start stirring and degassing, and record the gas measurement values of each component measured by the chromatograph; S2 When the drilling fluid in the first circulating tank in the circulating tank system is pumped out, quickly adjust the second valve (T2) to pump liquid from the second circulating tank; when the second circulating tank is pumped out, then adjust the second valve to pump liquid from other tanks outside the second circulating tank; S3 When the chromatograph shows that the gas in the drilling fluid is lower than the threshold, stop degassing, and open the third valve (T3) and the fourth valve (T4) to discharge all the drilling fluid in the circulating tanks.

8. The method for measuring the degassing efficiency of drilling fluid based on the multi-stage degassing-exponential cumulative first method according to claim 7, characterized in that, Perform exponential curve fitting on the gas component content data of the multi-stage degassing of the drilling fluid measured in the experiment, and determine the total gas content of the drilling fluid based on the exponentially fitted data.

9. The method for measuring the degassing efficiency of drilling fluid based on the multi-stage degassing-exponential cumulative first method according to claim 8, characterized in that, The total gas content is determined by accumulating two parts of data. One part of the data is the degassing amount of N experiments, and the other part of the data is the remaining degassing amount determined by the fitted data after N times.

10. The method for measuring the degassing efficiency of drilling fluid based on the multi-stage degassing-exponential cumulative first method according to claim 9, characterized in that, The degassing efficiency of the drilling fluid is determined by the ratio of the gas components after the first degassing to the total gas content.

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