Drilling fluid degassing efficiency determination device and method based on multi-stage degassing-index cumulative first effect method

Abstract

This invention discloses a drilling fluid degassing efficiency determination device and method based on a multi-stage degassing-index cumulative first-efficiency method, belonging to the field of oil and gas exploration. The device includes a circulation tank system, a stirring system, and a suction pump system. The circulation tank system includes at least two circulation tanks for alternately storing and transporting gas-bearing drilling fluid. The circulation tank system and the stirring system are intermittently connected via a first valve group and another intermittently connected via a second valve group. The exhaust port of the stirring tank is connected to a chromatograph via a gas pipeline. The suction pump system includes a suction pump, which is connected to the circulation tank via a fifth valve. The method uses experimentally measured multi-stage degassing gas component content data to perform exponential curve fitting to determine the total gas content of the drilling fluid. The degassing efficiency of the degasser on the drilling fluid is determined by the ratio of the gas components degassed in the first stage to the total gas content. This invention can accurately determine the drilling fluid degassing efficiency, providing a basis for accurately evaluating formation gas content.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration, specifically to a drilling fluid degassing efficiency measuring device and method based on the multi-stage degassing-index cumulative first-effect method. Background Technology

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

[0003] Commonly used degassers are classified into two types based on their continuous degassing capacity: non-quantitative degassers and quantitative degassers. The quantitative degasser GZG, commonly used in well logging gas testing, has a continuous drilling fluid extraction capacity of 1500 ml / min, and the stirring rod in the mixing tank rotates at a speed of 1400 rpm.

[0004] However, existing drilling fluid degassing efficiency measurement technologies still have some problems and shortcomings. First, traditional degassing devices typically use a single degassing tank design, which cannot achieve a continuous degassing process, resulting in low degassing efficiency. Second, existing technologies struggle to accurately measure the degassing efficiency of drilling fluids under different densities, temperatures, and viscosities, affecting the accuracy of gas logging data. Furthermore, existing degassing efficiency calculation methods often ignore the influence of residual gas in the drilling fluid, failing to fully reflect the true gas content of the drilling fluid.

[0005] In particular, existing technologies lack a device and method capable of achieving multi-stage degassing and accurately measuring degassing efficiency. In practical applications, a single degassing cycle often fails to completely remove gas from drilling fluid, requiring multiple degassing operations to obtain more accurate gas content data. However, existing technologies struggle to achieve continuous operation and precise measurement during multi-stage degassing processes and lack methods for accumulating degassing data, resulting in inaccurate degassing efficiency measurements and impacting the reliability and field applicability of geological logging data.

[0006] Therefore, there is an urgent need to develop a device and method that can adapt to different drilling fluid properties, achieve multi-stage continuous degassing, and accurately measure 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] To address the issues of complexity and inaccuracy in existing drilling fluid degassing efficiency measurement methods, as well as their inability to adapt to drilling fluids of different densities, temperatures, and viscosities, which affects the accuracy of gas logging data and reduces the reliability and field applicability of geological logging data, this invention provides a drilling fluid degassing efficiency measurement device and method based on the multi-stage degassing-index cumulative first-effect method.

[0008] The technical solution adopted by this invention to solve its technical problem is as follows: A drilling fluid degassing efficiency measuring device based on a multi-stage degassing-index cumulative first-effect method is provided, comprising a stirring tank, a suction pump system, wherein 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 comprising a circulation tank system, the circulation tank system including at least two circulation tanks, which alternately store and transport gas-containing drilling fluid; the stirring system and the circulation tank system are connected through a first valve group and a second valve group; the suction pump system includes a suction pump, which is connected to the circulation tank through a fifth valve. The drilling fluid degassing efficiency measuring device is mainly used to measure the degassing efficiency of drilling fluid by a drilling fluid degasser.

[0009] Furthermore, the at least two circulating tanks in the circulating tank system are controlled by a first valve to alternately input degassed drilling fluid from the stirring system into one circulating tank. The first valve is located between the circulating tanks. The first valve is a valve in the first valve group and is a three-way valve that connects the two circulating tanks and the stirring system respectively.

[0010] Furthermore, the circulating tank system further includes an air inlet, an exhaust outlet, a stirring tank, and a stirring motor. The drilling fluid input into the circulating tank system is degassed by stirring, and the degassed amount is measured by the chromatograph.

[0011] Furthermore, the second valve group includes a second valve, a sixth valve, and a fifth valve. The second valve is connected between the circulation tanks. Under the control of the second valve, drilling fluid flows out of the circulation tank alternately and is input into the mixing tank system via a suction pump.

[0012] Furthermore, a temperature sensor is installed between the second valve and the sixth valve, and a heating tape and a heating element are installed outside the circulation tank. The heating tape and heating element are controlled according to the temperature of the drilling fluid in the pipeline detected by the temperature sensor, so as to achieve a constant temperature of the fluid in the circulation pipeline.

[0013] This invention also provides a method for determining drilling fluid degassing efficiency based on multi-stage degassing-exponential cumulative first-efficiency method, comprising the following steps:

[0014] Drain the drilling fluid from the sample pool (called the "return tank" at the drilling site) and input it into the mixing tank. Adjust the first valve to allow the drilling fluid to flow into the first circulation tank and begin the first degassing. Observe the drilling fluid flowing into the first circulation tank until the tank is full and record the gas measurement values ​​of each component measured by the chromatograph.

[0015] When the first circulation tank is full, quickly adjust the second and fifth valves to draw fluid from the first circulation tank, while simultaneously adjusting the first valve to direct the fluid to the second circulation tank. When the drilling fluid in the first circulation tank is depleted, quickly adjust the second valve to draw fluid from the second circulation tank, while simultaneously adjusting the first valve to direct the fluid to the first circulation tank. When the second circulation tank is depleted, adjust the second valve again to draw fluid from the first circulation tank, while simultaneously adjusting the first valve to direct the fluid 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 content in the drilling fluid is below 0.01% or the gas measurement value is below 1% of the initial value, stop degassing and open the third and fourth valves to discharge all the drilling fluid from the circulation tanks.

[0016] Furthermore, the gas component content data of the drilling fluid after multi-stage degassing were obtained experimentally and subjected to exponential curve fitting. The total gas content of the drilling fluid was determined based on the exponential fitting data.

[0017] Furthermore, the total gas content is determined by accumulating two sets of data: one set is the amount of gas degassed in N experiments, and the other set is the remaining amount of gas degassed determined by fitting data after N experiments.

[0018] Furthermore, the degassing efficiency of the drilling fluid is determined by the ratio of the gas components obtained from the first degassing to the total gas content.

[0019] The beneficial effects of this invention are as follows: Through alternating pumping and purging in a circulating tank and a variable frequency stirring motor, continuous degassing experiments are achieved, dynamically capturing the gas release decay law, breaking through the static error limitation of traditional single-stage degassing, and improving the accuracy of degassing efficiency measurement, providing a basis for accurately evaluating formation gas content; the equipment is made of stainless steel and, through the integration of a temperature control system and a variable frequency pump, can simulate drilling fluid performance under complex working conditions such as drilling fluid density, temperature, and viscosity in real time, enhancing environmental adaptability and making it particularly suitable for offshore platforms and complex formations; based on the experimental data fitting exponential equation, a degassing concentration decay curve is constructed, and the total gas content formula is derived, solving the problem of extrapolating limited experimental data; after quantifying the degassing efficiency, a standardized correction basis is provided for gas logging interpretation, enhancing the accuracy of logging data and laying the foundation for horizontal comparison between wells and subsequent interpretation and evaluation of logging data. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 Overall design diagram for drilling fluid degassing efficiency measurement.

[0022] Figure 2 : Layout diagram of the first, second, third and fourth valves.

[0023] Figure 3 Fifth and sixth valve structure layout diagrams.

[0024] Figure 4 Test results of the first group of wells YL10-6-2.

[0025] Figure 5 Test results of the second group of well YL10-6-2.

[0026] Figure 6 Test results of the third group of well YL10-6-2.

[0027] Figure 7 Test results of the third group of wells DF11-2-1d.

[0028] Figure 8 Test results of the fourth group of wells DF11-2-1d.

[0029] Figure 9 Test results of the fifth group in well DF11-2-1d.

[0030] Figure 10 Test results of the sixth group of wells DF11-2-1d.

[0031] Figure 11 Test results of the seventh group of well DF11-2-1d.

[0032] Figure 12 Test results of the eighth group of well DF11-2-1d.

[0033] In the diagram: 1 – Liquid suction pump, 2 – Stirring motor, 3 – Stirring tank, 4 – Air inlet, 5 – Exhaust outlet, 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

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1:

[0036] This embodiment provides a drilling fluid degassing efficiency measuring device based on the multi-stage degassing-exponential cumulative first-efficiency method, such as... Figure 1 As shown, the device includes a mixing tank 3, a suction pump system, a circulation tank system, and a mixing system. The exhaust port 5 of the mixing tank 3 is connected to a gas pipeline, the other end of which is connected to a chromatograph. The circulation tank system includes at least two circulation tanks, A and B, which alternately store and transport gas-containing drilling fluid. The mixing system and the circulation tank system are intermittently connected via a first valve group and a second valve group; the suction pump system includes a suction pump, which is connected to the circulation tank via a fifth valve.

[0037] In the circulating tank system, two circulating tanks, A and B, are controlled by a first valve T1. They alternately input degassed drilling fluid from the agitation system into one circulating tank. The first valve T1 is located between the circulating tanks. The first valve T1 is a three-way valve, connecting both circulating tanks and the agitation system. Both circulating tanks A and B have a volume of 18L, are made of stainless steel, and can withstand a pressure of 0.5MPa. The outer walls of both circulating tanks A and B are wrapped with a 200W heating cable and heating strip. The heating cable and heating strip are connected to a temperature sensor 11 via a temperature controller. When the temperature sensor 11 detects that the drilling fluid temperature in the pipeline is lower than the set value, the temperature controller activates the heating cable to heat the fluid. Two insulated tanks are used for circulating degassed fluid. The main body of the equipment is made of stainless steel and is suitable for offshore platform environments. The insulated tanks maintain the mud temperature by wrapping the outer wall with explosion-proof heating tape, and an online thermometer is installed to monitor the mud temperature in real time. A flip cover 9 is installed at the top of the circulation tanks A and B. After opening the flip cover 9, drilling fluid before degassing can be injected into the circulation tanks A and B. The filter screen 10 can remove impurities in the drilling fluid to prevent impurities from clogging the pipelines and related valves.

[0038] The mixing system includes an air inlet 4, an exhaust outlet 5, a mixing tank 3, and a mixing motor 2. The drilling fluid input into the circulation tank system is degassed by mixing, and the degassed amount is measured using a chromatograph. The mud pumping rate is 1.5 liters / minute, and the mixing tank motor speed is 1400 rpm. The second valve group includes the second valve T2, the fifth valve T5, and the sixth valve T6 (e.g., ...). Figure 3As shown, the second valve T2 is connected between circulation tanks A and B. Controlled by the second valve T2, drilling fluid alternately flows out of circulation tanks A and B and is pumped into the mixing tank system via the suction pump 1. A temperature sensor 11 is installed between the second valve T2 and the fifth valve T5. A heating tape and a heating element are installed outside circulation tanks A and B. The heating tape and heating element are controlled based on the temperature of the drilling fluid in the pipeline detected by the temperature sensor 11, thus maintaining a constant temperature of the fluid in the circulation pipeline. A third valve T3 and a fourth valve T4 are connected to the outside of circulation tanks A and B, respectively. When the entire device stops degassing, the third valve T3 and the fourth valve T4 open, draining the drilling fluid from circulation tanks A and B, facilitating subsequent cleaning of circulation tanks A and B.

[0039] The volume of the mixing tank 3 is customized according to the amount of drilling fluid, with a 1.5L option available. It is also made of stainless steel and can withstand a pressure of 1MPa. A stirring motor 2 is installed at the top of the mixing tank 3. The stirring motor 2 has a power of 1.5kW and a maximum speed of 1500rpm. The shaft of the stirring motor 2 is connected to a stirring paddle, which features a four-blade design. This paddle creates strong turbulence within the mixing tank 3, promoting the release of gas from the drilling fluid.

[0040] The top of the mixing tank 3 is also equipped with an air inlet 4 and an exhaust port 5. The air inlet 4 is connected to an air supply system, which can introduce nitrogen or air into the mixing tank 3 to regulate the pressure inside. The exhaust port 5 is connected to a gas pipeline, the other end of which is connected to a gas chromatograph. The gas chromatograph is capable of qualitative and quantitative analysis of the gas components extracted from the drilling fluid, with a detection accuracy of up to 0.0001%.

[0041] The first valve, T1, can be either a manual three-way valve or an electric three-way valve. If it is a manual three-way valve, the operator switches it manually based on their judgment. If it is an electric three-way valve, it can be remotely controlled through the control system, with a switching time of less than 1 second. The second valve, T2, is also either a manual or electric three-way valve and has the same performance parameters.

[0042] The suction pump 1 is a diaphragm pump, which draws in mud. The pump speed (displacement) is adjusted by a variable frequency pump, and the stirring speed is adjusted by a variable frequency motor. A heating tape maintains the mud temperature, and a heating belt heats the mud. The same sample is degassed multiple times, and the degaussing efficiency is measured. Then, the data is corrected to restore the true gas content in the mud, improving the gas group resolution and the accuracy of gas measurement interpretation.

[0043] When the equipment is tested at the drilling site, drilling fluid is drawn from the return channel at the drilling site. The fifth valve, T5, is used to directly draw drilling fluid from the return channel, and the fluid enters the mixing tank 3 for the first degassing under the drive of the suction pump system. After the first degassing, the drilling fluid flows into the circulation tank (A / B) under the influence of gravity. Therefore, in this design, the mixing tank is positioned higher than the circulation tank (A / B), especially the outlet of the mixing tank 3 is higher than the inlet of the circulation tank (A / B). Then, driven by the suction pump system, fluid is drawn from the circulation tank (A / B) for the second, third, fourth, and fifth degassing processes. When the equipment is not tested at the drilling site, fluid is drawn from the circulation tank (A / B), and the drilling fluid in the circulation tank (A / B), as described above, is directly injected into the circulation tank (A / B) through the flip-top 9 and filter screen 10.

[0044] T6 is a manual three-way valve, but an electric device can also be selected. It measures the flow rate of drilling fluid after being pressurized by suction pump 1. If the flow rate in the passage exceeds a threshold, the power of suction pump 1 is reduced; if the flow rate in the passage is below the threshold, the power of suction pump 1 is increased. In this scheme, the pump flow rate is manually adjusted, but it can also be further automated by using an electric method.

[0045] Example 2:

[0046] This embodiment provides a method for determining the degassing efficiency of drilling fluid based on the multi-stage degassing-index cumulative first-effect method. The method uses the measuring device described in Embodiment 1, and the measurement steps using the measuring device include the following.

[0047] Step 1: Equipment preparation and connection;

[0048] Power Connection: Ensure the equipment is correctly connected to a 220V power supply and check that the power cord connection is secure. Gas Line Connection: Connect one end of the gas line to the exhaust port 5 of the mixing tank 3 of the equipment, and the other end to the sample inlet of the chromatograph. Ensure the connection is well sealed to prevent gas leakage.

[0049] Step 2: Adjust equipment parameters;

[0050] Pump Displacement Adjustment: Adjust the displacement of pump 1 to 1500 ml / min (Adjustment method: Turn on the suction pump, draw drilling fluid from valve T5, and discharge it from valve T6. Use a stopwatch and measuring cup to measure the flow rate. Rotate the flow rate adjustment knob on the suction pump body until the measured value is 1500 ml / min). This can be set through the control panel of the variable frequency pump. Agitation Speed ​​Adjustment: Adjust the agitation speed of the stirring rod to 1400 rpm (adjust the knob inside the explosion-proof enclosure as follows). Figure 2 (As shown). This can be set through the control panel of the variable frequency motor.

[0051] Step 3: Begin the degassing cycle;

[0052] Adjust valve T5 to draw liquid from the sample pool (called "reflux tank" at the drilling site), adjust valve T5 to flow towards mixing tank 3, and adjust valve T1 to flow towards tank A 7; turn on the main power switch, the liquid pump switch, and the temperature tracing switch in sequence, and the measuring device will begin the first degassing; observe the drilling fluid flowing towards tank A until the tank is full, and record the gas measurement values ​​of each component measured by the chromatograph;

[0053] If the site is not suitable for liquid extraction, the liquid in the sample cell, i.e., the gas-containing drilling fluid, can be directly poured into circulation tank A.

[0054] The equipment is then started: turn on the main power switch, the liquid pump switch, and the heat tracing switch in sequence. The degassing process begins.

[0055] Step 4: Gas analysis;

[0056] Chromatographic analysis: The extracted gases are analyzed using a chromatograph, and the results are recorded. This helps determine the gas content and composition in the mud.

[0057] Step 5: Switching the circulating tank;

[0058] From Tank A to Tank B: When the drilling fluid in Tank A is depleted, quickly switch valve T2 to draw fluid from Tank B, and simultaneously switch valve T1 to flow to Tank A. This will begin drawing mud from Tank B for degassing. From Tank B to Tank A: When the drilling fluid in Tank B is depleted, quickly switch valve T2 to draw fluid from Tank A, and simultaneously switch valve T1 to flow to Tank B. This will restart drawing mud from Tank A for degassing.

[0059] Step 6: Repeat the degassing process;

[0060] Repeat steps 5 and 6: Continue repeating the above steps until the gas meter shows that the gas content in the drilling fluid has dropped below 0.01%, or the gas reading is below 1% of the initial value. This indicates that the gas content in the drilling fluid has been reduced to a low level.

[0061] Step 7: Clean the equipment;

[0062] Draining Mud: After testing, open valves T3 and T4 to drain the drilling fluid from tanks A and B. Cleaning Tanks and Pipelines: Pour clean water into tanks A and B and rinse away any remaining drilling fluid from the pipelines. Ensure all components are thoroughly cleaned to prevent cross-contamination.

[0063] The gas component content data of the drilling fluid after multi-stage degassing, obtained from the experiment, were fitted with an exponential curve. The fitted curve is shown in the figure. Figure 4-12Simultaneously, the total gas content of the drilling fluid is determined based on exponential fitting data. According to the degassing efficiency experiment, the measured values ​​of a certain gas component degassing in each experiment are defined as a1, a2, a3...an. The x-th degassing value obtained by the exponential curve fitting of the experimental data is S. The total gas content of that component in the drilling fluid is the sum of the measured values ​​from the degassing experiment and the values ​​calculated from the subsequent exponential curve fitting. a-y Total gas content calculation: (N = number of experiments); Formula for the degassing efficiency of this component in drilling fluid: Accurately assessing the initial degassing rate provides a standardized calibration basis for gas measurement interpretation.

[0064] The gas component content data of the drilling fluid after multi-stage degassing, obtained from the experiment, were fitted with an exponential curve. The fitted curve is shown in the figure. Figure 4-12 Simultaneously, the total gas content of the drilling fluid is determined based on exponential fitting data. According to the degassing efficiency experiment, the measured values ​​of a certain gas component degassing in each experiment are defined as a1, a2, a3...an. The x-th degassing value obtained by the exponential curve fitting of the experimental data is S. The total gas content of that component in the drilling fluid is the sum of the measured values ​​from the degassing experiment and the values ​​calculated from the subsequent exponential curve fitting. a-y Total gas content calculation: (N = number of experiments); formula for drilling fluid degassing efficiency of this component: Accurately assessing the initial degassing rate provides a standardized calibration basis for gas measurement interpretation.

[0065] This experiment was conducted nine times in two wells, YC36-2-1 and DF11-2-1d, in a certain oilfield. The results are shown in Table 1. Figure 4-12 As shown in Table 1, Figure 4-12 It can be seen that the degassing efficiency curves obtained from each well are basically the same, and there is a common pattern: as the number of carbon atoms increases, the degassing efficiency gradually decreases. This indicates that the larger the number of carbon atoms in hydrocarbon gases, the stronger their ability to be adsorbed in the drilling fluid, the more difficult it is to remove them from the drilling fluid, and the lower the degassing efficiency, which is consistent with theory. The drilling fluid degassing efficiency of this invention is of great significance for the discovery, interpretation, and evaluation of oil and gas reservoirs. During the logging process, this value can be used to correct gas measurement values ​​in real time, enhance the accuracy of logging data, and lay the foundation for lateral comparison between wells and subsequent interpretation and evaluation of logging data.

[0066] Table 1. Degassing efficiency of various components of gas in different wells.

[0067]

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions 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.

[0069] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and incorporate common knowledge or customary techniques in the art disclosed herein. The specification and examples are to be considered exemplary only, and the true scope of this application is indicated by the claims.

Claims

1. A multi-stage degassing-index cumulative first effect method based drilling fluid degassing efficiency measuring device, comprising a stirring system and a liquid suction pump system, the stirring system comprising a stirring tank (3), an air pipe line being connected to an exhaust port (5) of the stirring tank (3), and the other end of the air pipe line being connected to a chromatograph, characterized in that, The system further includes a circulation tank system, which comprises at least two circulation tanks (A and B) that alternately store and transport gaseous drilling fluid; the stirring system is connected to the circulation tank system via a first valve group and a second valve group; and the suction pump system includes a suction pump that is connected to the circulation tanks (A and B) via a fifth valve.

2. The drilling fluid degassing efficiency measuring device based on the multi-stage degassing-exponential cumulative first-effect 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) to alternately input degassed drilling fluid from the stirring system into the circulating tanks. The first valve (T1) is located between the circulating tanks. The first valve (T1) is a three-way valve, which is connected to two circulation tanks and a stirring system respectively.

3. The multi-stage degassing-index cumulative first effect method based drilling fluid degassing efficiency measurement apparatus according to claim 2, characterized in that, The first valve (T1) is one of the valves in the first valve group.

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

5. The drilling fluid degassing efficiency measuring device based on the multi-stage degassing-exponential cumulative first-efficiency 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 circulation tanks (A and B). Under the control of the second valve (T2), drilling fluid flows out of the circulation tanks (A and B) alternately and is input into the stirring system through the suction pump (1).

6. The drilling fluid degassing efficiency measuring device based on the multi-stage degassing-exponential cumulative first-effect method according to claim 5, characterized in that, A temperature sensor (11) is provided between the second valve (T2) and the fifth valve (T5). A heating tape is provided outside the circulation tanks (A, B). The heating tape is heated according to the temperature of the drilling fluid in the pipeline detected by the temperature sensor (11) to achieve a constant temperature of the fluid in the circulation pipeline.

7. A method for determining drilling fluid degassing efficiency based on multi-stage degassing-exponential cumulative first-effect method, characterized in that, Using the measuring apparatus according to any one of claims 1-6, the method comprises the following steps: S1 draws drilling fluid from the return tank at the drilling site and inputs it into the mixing tank. The first valve is adjusted to allow the drilling fluid to flow into the first circulation tank. Stirring and degassing are started, and the flow of drilling fluid into the first circulation tank is observed until the tank is full. The gaseous values ​​of each component measured by the chromatograph are recorded. Alternatively, the sample or the sample taken from the return tank at the drilling site is directly filled into the first circulation tank until it is full. Stirring and degassing are started, and the gaseous values ​​of each component measured by the chromatograph are recorded. When the drilling fluid in the first circulating tank of the circulating tank system is exhausted, the second valve (T2) is quickly adjusted to draw fluid from the second circulating tank; when the second circulating tank is exhausted, the second valve is adjusted again to draw fluid from other tanks outside the second circulating tank. S3 stops degassing when the chromatograph shows that the gas content in the drilling fluid is below the threshold, and opens the third valve (T3) and the fourth valve (T4) to discharge all the drilling fluid from the circulating tank.

8. The method for determining drilling fluid degassing efficiency based on multi-stage degassing-exponential cumulative first-efficiency method according to claim 7, characterized in that, The gas component content data of the drilling fluid after multi-stage degassing were obtained experimentally and subjected to exponential curve fitting. The total gas content of the drilling fluid was determined based on the exponential fitting data.

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

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

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