Method and device for quantitatively evaluating degassing efficiency of mud gas detector degasser

Abstract

The present application relates to oil and gas exploration and development technical field, more particularly, to a kind of quantitative evaluation mud gas logging degasser degassing efficiency method, specifically comprising: detecting the air tightness of experimental barrel;Quantitative volume V 泥浆 Mud is added and quantitative volume V 注气 The specified concentration ratio of hydrocarbon gas is added to the experimental barrel;The mud in the experimental barrel is stirred by stirring device, so that the hydrocarbon gas injected into the experimental barrel is fully dissolved in the mud in the experimental barrel;Test the concentration Cn 空腔 Of hydrocarbon gas in the cavity at the top of experimental barrel;The mud degassing treatment is carried out on the mud in the experimental barrel by the mud gas logging degasser to be evaluated, and the concentration Cn 泥浆 Of hydrocarbon gas in the mud is obtained;Calculate the hydrocarbon gas degassing efficiency of the mud gas logging degasser to be evaluated.The whole operation process of the present application is simple and clear, the degassing efficiency of the degasser can be quantitatively evaluated, the real gas logging value of different hydrocarbon components can be quantitatively corrected, and the reliability and accuracy of gas logging data can be improved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration and development technology, and more specifically, to a method and apparatus for quantitatively evaluating the degassing efficiency of a mud gas degasser. Background Technology

[0002] Gas logging is a technique for continuously monitoring formation oil and gas displays at the wellhead. Whether in shallow or deep formations, gas logging is a crucial method for oil and gas discovery and evaluation. Gas data acquisition can be divided into two main parts: gas collection and gas detection. Gas detection relies on relatively mature chromatographs, while the gas collection stage still commonly uses electric degassing devices. The stability of the latter's degassing efficiency is the biggest factor affecting the accuracy of gas logging data.

[0003] Degassing efficiency refers to the proportion of gas removed from the drilling fluid in a single operation by a degasser, relative to the total gas content of the drilling fluid. Theoretically, no degassing device can completely remove hydrocarbon gases from drilling fluid in a single operation; even with multiple degassing cycles, only a portion of the hydrocarbon gases in the drilling fluid is removed. Drilling conditions have a significant impact on degassing efficiency. For example, oil-based drilling fluids have the best degassing efficiency, followed by silicate and formate fluids, while water-based drilling fluids have the worst. When gas saturation and viscosity are the same, the measured values ​​for oil-based drilling fluids are much higher than those for water-based drilling fluid systems.

[0004] There are currently two approaches to degassing efficiency calibration experiments. One approach, proposed by Sino-French Bohai Geological Services Co., Ltd., involves repeatedly degassing a quantitative amount of drilling fluid and evaluating the degassing efficiency of each component using the data results. This method is specifically designed for degassers such as GZG that can be degassed multiple times. The other approach involves taking a sample at the inlet of the electric degasser for thermal vacuum quantitative total degassing analysis to detect the total hydrocarbon gas content in the drilling fluid before degassing. Then, a sample is taken at the outlet of the electric degasser for thermal vacuum quantitative total degassing analysis to detect the hydrocarbon gas content in the drilling fluid after degassing. Finally, the ratio of the hydrocarbon gas content after degassing to that before degassing is calculated, which represents the proportion of "residual" gas in the drilling fluid, thus evaluating the degassing efficiency.

[0005] It is obvious that different types of degassers have different abilities to remove hydrocarbon gases from mud, i.e., different degassing efficiencies. When using hydrocarbon gas data collected from different degassers, it is necessary to correct them according to the degassing efficiency. However, the current methods for testing or evaluating the degassing efficiency of degassers are quite complex, and some methods are only applicable to specific types of degassers. Summary of the Invention

[0006] To overcome the limitations of existing technologies, which require evaluating the degassing efficiency of mud gas analyzers to improve the reliability and accuracy of gas measurement data, this invention provides a method and apparatus for quantitatively evaluating the degassing efficiency of mud gas analyzers that is simple to evaluate, easy to operate, and highly applicable.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for quantitatively evaluating the degassing efficiency of a mud gas degasser, specifically including the following steps:

[0008] Step 1: Test the airtightness of the experimental container;

[0009] Step 2: Measure the volume V 泥浆 Add the mud slurry into the experimental bucket, close the lid, and add a quantitative volume V. 注气 A specified concentration of hydrocarbon gas is injected into the experimental barrel through the gas injection channel.

[0010] Step 3: Stir the mud in the experimental barrel using a stirring device to ensure that the hydrocarbon gas injected into the experimental barrel in Step 2 is fully dissolved in the mud in the experimental barrel;

[0011] Step 4: Open the gas outlet of the experimental barrel, extract the hydrocarbon gas from the top cavity of the experimental barrel, and measure the concentration Cn of the hydrocarbon gas in the top cavity of the experimental barrel. 空腔 ;

[0012] Step 5: Open the bucket lid and use the mud gas degassing device to degas the mud in the experimental bucket to obtain the hydrocarbon gas concentration Cn in the mud. 泥浆 ;

[0013] Step 6: Calculate the hydrocarbon gas degassing efficiency of the mud gas degasser to be evaluated.

[0014] This invention involves adding a fixed volume of mud slurry to an experimental tank, sealing the tank and ensuring good airtightness, then injecting a fixed volume of hydrocarbon gas at a specified concentration ratio into the tank from the outside. A stirring device is used to ensure the hydrocarbon gas is fully dissolved in the mud. The concentration of hydrocarbon gas in the cavity at the top of the experimental tank is analyzed. The tank is then opened, and the hydrocarbon gas is removed from the mud using a mud gas analyzer to be evaluated, and the concentration is measured. Finally, the hydrocarbon degassing efficiency of the mud gas analyzer to be evaluated is calculated. This invention, by injecting a fixed amount of gas into a fixed amount of mud slurry to saturate it, and then measuring and calculating the true volume of saturated hydrocarbon gas in the mud, can quantitatively evaluate the degassing efficiency of a specified model of mud gas analyzer. The entire operation process is simple, clear, and easy for experimental personnel to understand and operate. It has wide applicability, and the obtained degassing efficiency evaluation results can significantly improve the reliability and accuracy of gas measurement data.

[0015] Preferably, the specific method for testing the airtightness of the experimental barrel in step one is as follows: First, close the lid onto the experimental barrel and shut off the air outlet channel; then, use an air compressor to inject high-pressure air into the experimental barrel through the air injection channel for 1 to 3 minutes; finally, close the air injection channel and test the pressure value of the experimental barrel. After 30 to 40 minutes, test the pressure value inside the experimental barrel again. If the difference between the pressure values ​​before and after is less than 0.01 MPa, the experimental barrel has good airtightness and can be used for subsequent operations; otherwise, the experimental barrel has poor airtightness.

[0016] Preferably, in step three, the stirring speed of the stirring device is 1000 rpm to 1500 rpm, the stirring time is 30 minutes to 40 minutes, and after the stirring device finishes stirring, the experimental container is left to stand for 10 minutes to 15 minutes.

[0017] Preferably, in step four, the concentration of hydrocarbon gas Cn in the top cavity of the experimental barrel is... 空腔 The specific testing method is as follows: Open the gas outlet channel of the experimental barrel, connect the gas inlet line of the gas chromatograph to the gas outlet channel of the experimental barrel, and continuously test and analyze for at least 10 chromatograph test cycles to finally obtain the hydrocarbon gas concentration Cn in the top cavity of the experimental barrel. 空腔 .

[0018] Preferably, in step five, the inlet of the mud degassing device to be evaluated is placed at the center of the experimental barrel to degas the mud in the experimental barrel until there is no mud in the inlet pipe of the degassing device to be evaluated.

[0019] Preferably, the specific calculation steps for the hydrocarbon gas degassing efficiency of the mud gas degasser to be evaluated in step six are as follows:

[0020] First, subtract the mud volume V from the total volume V of the experimental bucket. 泥浆 The volume V of the cavity at the top of the experimental barrel was obtained. 空腔 ;

[0021] V 空腔 =VV 泥浆

[0022] Then, the volume V of the cavity at the top of the experimental barrel was... 空腔 Multiply by the concentration of hydrocarbon gas in the top cavity of the experimental barrel, Cn 空腔 The pure volume Vn of hydrocarbon gas in the top cavity of the experimental barrel was obtained. 空腔 ;

[0023] Vn 空腔 =V 空腔 ×Cn 空腔

[0024] Secondly, a quantitative volume V of hydrocarbon gas was injected into the experimental barrel.注气 Subtract the pure volume of hydrocarbon gas in the top cavity of the experimental barrel, Vn 空腔 The pure volume Vn of hydrocarbon gas dissolved in the mud was obtained. 泥浆 ;

[0025] Vn 泥浆 =V 注气 -Vn 空腔

[0026] Finally, the concentration of hydrocarbon gases Cn in the mud obtained from the degasser to be evaluated will be... 泥浆 Multiply by the mud volume V 泥浆 Then divide by the pure volume of hydrocarbon gases dissolved in the mud, Vn 泥浆 The hydrocarbon gas degassing efficiency η of the degasser to be evaluated can be obtained. n ;

[0027] η n =Cn 泥浆 ×V 泥浆 / Vn 泥浆

[0028] That is, η n =Cn 泥浆 ×V 泥浆 / {V 注气 -(VV 泥浆 )×Cn 空腔}

[0029] A device for quantitatively evaluating the degassing efficiency of a mud gas degasser includes an experimental barrel and a lid that can be closed onto the experimental barrel; the lid is provided with a means for quantitatively measuring volume V. 注气 The test chamber is equipped with an injection channel for injecting hydrocarbon gas at a specified concentration ratio and an outlet channel for discharging hydrocarbon gas from the top cavity of the test chamber; the chamber lid is also connected to a stirring device for stirring the mud inside the test chamber.

[0030] Preferably, the stirring device includes a driving component, a stirring rod, and stirring blades; one end of the stirring rod is connected to the output shaft of the driving component, and the other end extends into the experimental barrel; the stirring blades are located at the end of the stirring rod inside the experimental barrel.

[0031] Preferably, a first valve for controlling the opening and closing of the gas injection channel is connected to the gas injection channel located outside the experimental barrel; the length of the gas injection channel located inside the experimental barrel is 3 / 5 to 4 / 5 of the height of the experimental barrel.

[0032] Preferably, a pressure gauge and a second valve for controlling the opening and closing of the air outlet channel are connected to the air outlet channel located outside the experimental barrel; the pressure gauge is located between the barrel lid and the second valve, and the length of the air outlet channel located inside the experimental barrel is 1 / 5 to 2 / 5 of the height of the experimental barrel.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1) This invention saturates a quantitative amount of gas into a quantitative amount of mud, and detects and calculates the true volume of hydrocarbon gas saturated in the mud. This enables quantitative evaluation of the degassing efficiency of different degassers, thereby quantitatively correcting the true gas measurement values ​​of different hydrocarbon components. This can effectively improve the reliability and interpretation accuracy of gas measurement data.

[0035] 2) The device of the present invention is simple to set up, and the whole operation process is concise and clear, which is easy for experimental personnel to understand and operate. It can evaluate the degassing efficiency of specific degassers under different drilling fluid performance conditions, and has high applicability. Attached Figure Description

[0036] Figure 1 This is a flowchart illustrating the method for quantitatively evaluating the degassing efficiency of a mud gas degasser according to the present invention.

[0037] Figure 2 This is a schematic diagram of the structure of the device for quantitatively evaluating the degassing efficiency of the mud gas measuring degasser of the present invention;

[0038] Figure 3 This is a partial structural schematic diagram of the device for quantitatively evaluating the degassing efficiency of the mud gas measuring degasser of the present invention.

[0039] Figure 4 This is a schematic diagram of the internal structure of the device for quantitatively evaluating the degassing efficiency of the mud gas measuring degasser of the present invention.

[0040] Figure 5 This is a schematic diagram of the structure of the first and second valves of the device for quantitatively evaluating the degassing efficiency of the mud gas measuring degasser of the present invention.

[0041] In the attached diagram: 1-Experimental barrel; 11-Injection channel; 111-First valve; 12-Outlet channel; 121-Pressure gauge; 122-Second valve; 2-Barrel lid; 3-Stirring device; 31-Driver; 32-Stirring rod; 33-Stirring blade. Detailed Implementation

[0042] The accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0043] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "long," and "short" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0044] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0045] Example 1

[0046] like Figures 1-5 The diagram illustrates a method and apparatus for quantitatively evaluating the degassing efficiency of a mud gas degasser. Specifically, as shown... Figures 2-5 The device shown is a device for quantitatively evaluating the degassing efficiency of a mud gas degasser, including an experimental barrel 1, a barrel lid 2, and a stirring device 3. In this embodiment, the experimental barrel 1 is a hollow cylindrical structure with an open top. The barrel lid 2 can be closed to the opening at the top of the experimental barrel 1 and is tightened onto the experimental barrel 1 by a buckle.

[0047] The stirring device 3 is used to stir the mud in the experimental barrel 1 so that the hydrocarbon gas injected into the experimental barrel 1 is fully dissolved in the mud. Specifically, the stirring device 3 includes a drive component 31, a stirring rod 32, and a stirring blade 33. The drive component 31 is a pneumatic motor, and the stirring rod 32 is a solid steel rod. One end of the stirring rod 32 is located outside the experimental barrel 1 and is connected to the output end of the drive component 31. The other end of the stirring rod 32 extends into the interior of the experimental barrel 1. The barrel cover 2 is provided with a through hole 13 for the stirring rod 32 to pass through. The length of the stirring rod 32 located inside the experimental barrel 1 is 4 / 5 of the height of the experimental barrel 1. The stirring blade 33 is connected to the end of the stirring rod 32 located inside the experimental barrel 1.

[0048] In use, the pneumatic drive unit 31 drives the stirring rod 32 to rotate, which in turn drives the stirring blade 33 to rotate and stir the mud inside the experimental barrel 1.

[0049] The lid 2 is also equipped with an injection channel 11 and an outlet channel 12. The injection channel 11 is used to inject a quantitative volume V. 注气 A specified concentration of hydrocarbon gas is introduced into the experimental barrel 1. The gas outlet channel 12 is used to discharge the hydrocarbon gas in the top cavity of the experimental barrel 1. The hydrocarbon gas in the top cavity of the experimental barrel 1 can be extracted through the gas outlet channel 12.

[0050] Specifically, the gas injection channel 11 is a hollow steel pipe. One end of the gas injection channel 11 is located outside the experimental barrel 1, and the other end is located inside the experimental barrel 1. A first valve 111 is connected to the gas injection channel 11 located outside the experimental barrel 1. The first valve 111 is used to close and open the gas injection channel 11. In this embodiment, the first valve 111 is a ball valve.

[0051] The length of the air injection channel 11 located inside the experimental barrel 1 is 4 / 5 of the height of the experimental barrel 1. When mud is added to the experimental barrel 1, the end of the air injection channel 11 is located inside the mud.

[0052] The air outlet channel 12 is a hollow steel pipe. One end of the air outlet channel 12 is located outside the experimental barrel 1, and the other end is located inside the experimental barrel 1. A pressure gauge 121 and a second valve 122 are connected to the air outlet channel 12 located outside the experimental barrel 1. The pressure gauge 121 is used to measure the pressure data inside the experimental barrel 1, and the second valve 122 is used to close and open the air outlet channel 12. The pressure gauge 121 is located between the barrel cover 2 and the second valve 122. In this embodiment, the second valve 122 is a ball valve.

[0053] The length of the venting channel 12 located inside the experimental barrel 1 is 1 / 5 of the height of the experimental barrel 1. When mud is added to the experimental barrel 1, the end of the venting channel 12 is located above the mud, and the hydrocarbon gas in the top cavity of the experimental barrel 1 can be discharged through the venting channel 12.

[0054] like Figure 1 As shown, the present invention also provides a method for quantitatively evaluating the degassing efficiency of a mud gas degasser using the above-mentioned device, specifically including the following steps:

[0055] Step 1: Test the airtightness of experimental container 1;

[0056] Step 2: Measure the volume V 泥浆 Add the mud slurry into experimental bucket 1, close the bucket lid 2 onto experimental bucket 1, and add a quantitative volume V. 注气 A specified concentration of hydrocarbon gas is injected into experimental barrel 1 through the gas injection channel 11.

[0057] Step 3: Stir the mud in the experimental tank 1 using the stirring device 3 to ensure that the hydrocarbon gas injected into the experimental tank 1 in step 2 is fully dissolved in the mud in the experimental tank 1;

[0058] Step 4: Open the gas outlet channel 12 of experimental barrel 1, extract the hydrocarbon gas from the top cavity of experimental barrel 1, and measure the concentration Cn of the hydrocarbon gas in the top cavity of experimental barrel 1. 空腔 ;

[0059] Step 5: Open the lid 2 of the bucket and use the mud gas degassing device to degas the mud in the experimental bucket 1 to obtain the concentration of hydrocarbon gases Cn in the mud. 泥浆 ;

[0060] Step 6: Calculate the hydrocarbon gas degassing efficiency of the mud gas degasser to be evaluated.

[0061] The specific method for testing the airtightness of experimental container 1 in step one above is as follows:

[0062] First, put the lid 2 on the experimental barrel 1 and tighten the buckle. Then, close the second valve 122 on the air outlet channel 12 of the experimental barrel 1, that is, close the air outlet channel 12 of the experimental barrel 1.

[0063] Then, a 0.1 MPa air compressor was used to inject high-pressure air into the test chamber 1 through the air injection channel 11 for 1 minute;

[0064] Finally, close the first valve 111 of the gas injection channel 11 on the experimental barrel 1, that is, close the gas injection channel 11 of the experimental barrel 1. Read the pressure value of the experimental barrel 1 through the pressure gauge 121. Read the pressure value inside the experimental barrel 1 again after 30 minutes. If the difference between the pressure values ​​before and after is less than 0.01 MPa, the experimental barrel 1 has good sealing performance and can be used for subsequent operations; otherwise, the experimental barrel 1 has poor sealing performance.

[0065] The specific operation of step two above is as follows: The quantitative volume V... 泥浆 Add the specified performance mud to the experimental barrel 1, tightly seal the barrel lid 2 onto the experimental barrel 1, close the second valve 122 on the air outlet channel 12, open the first valve 111 on the air injection channel 11, and add a quantitative volume V. 注气 A specified concentration of hydrocarbon gas is injected into experimental tank 1 through the injection channel 11. After the injection is completed, the first valve 111 on the injection pipeline 11 is closed. The properties of the mud and the concentration ratio of the hydrocarbon gas are consistent with the mud performance range and oil and gas reservoir properties commonly used in the field.

[0066] The specific operation of step three above is as follows: the pneumatic drive unit 31 drives the stirring blade 33 to rotate through the stirring rod 32. During the rotation of the stirring blade 33, the mud in the experimental barrel 1 is stirred so that the hydrocarbon gas injected into the experimental barrel 1 is fully dissolved in the mud. During stirring, the stirring speed is 1000 rpm and the stirring time is 30 minutes. After stirring, the experimental barrel 1 is left to stand for 10 minutes.

[0067] The specific operation of step four above is as follows: Open the second valve 122 on the gas outlet channel 12 to analyze the hydrocarbon gas concentration in the top cavity of the experimental barrel 1. Specifically, connect the other side of the ball valve to the gas chromatograph's inlet line, and connect the end of the gas outlet channel 12 located outside the experimental barrel 1 to the gas chromatograph's inlet line. Analyze continuously for at least 10 chromatograph test cycles to obtain the hydrocarbon gas concentration Cn in the top cavity of the experimental barrel 1. 空腔 The gas chromatograph is a conventional gas chromatograph, and its specific structure and principle will not be described in detail here.

[0068] The specific operation of step five above is as follows: Open the bucket lid 2, place the inlet of the mud gas analyzer to be evaluated at the center of the experimental bucket 1, and perform mud degassing treatment on the mud in the experimental bucket 1 until there is no mud in the inlet pipe of the degasser to be evaluated, and obtain the hydrocarbon gas concentration Cn in the mud. 泥浆 ;

[0069] The specific calculation steps for the hydrocarbon gas degassing efficiency of the mud gas analyzer to be evaluated in step six above are as follows:

[0070] First, subtract the mud volume V from the total volume V of the experimental bucket. 泥浆 The volume V of the top cavity of the experimental barrel (1) was obtained. 空腔 The total volume V of the experimental barrel can be obtained by measurement.

[0071] V 空腔 =VV 泥浆

[0072] Then, the volume V of the cavity at the top of the experimental barrel (1) is... 空腔 Multiply by the concentration of hydrocarbon gas in the top cavity of the experimental barrel (1), Cn 空腔 The pure volume Vn of hydrocarbon gas in the top cavity of the experimental barrel (1) was obtained. 空腔 ;

[0073] Vn 空腔 =V 空腔 ×Cn 空腔

[0074] Secondly, a quantitative volume V of hydrocarbon gas was injected into the experimental container (1). 注气 Subtract the pure volume of hydrocarbon gas Vn in the top cavity of the experimental barrel (1). 空腔 The pure volume Vn of hydrocarbon gas dissolved in the mud was obtained. 泥浆 ;

[0075] Vn 泥浆 =V 注气 -Vn 空腔

[0076] Finally, the concentration of hydrocarbon gases Cn in the mud obtained from the degasser to be evaluated will be...泥浆 Multiply by the mud volume V 泥浆 Then divide by the pure volume of hydrocarbon gases dissolved in the mud, Vn 泥浆 The hydrocarbon gas degassing efficiency η of the degasser to be evaluated can be obtained. n ;

[0077] η n =Cn 泥浆 ×V 泥浆 / Vn 泥浆

[0078] That is, η n =Cn mud × V mud / {V air injection - (VV mud) × Cn cavity}.

[0079] This invention saturates a quantitative amount of gas into a quantitative amount of mud and measures the true volume of hydrocarbon gases in the saturated mud. This allows for the quantitative evaluation of the degassing efficiency of different degassers, thereby quantitatively correcting the true gas measurement values ​​of different hydrocarbon components. Ultimately, this effectively improves the reliability and interpretation accuracy of gas measurement data.

[0080] Example 2

[0081] This embodiment is embodiment 2 of a method and apparatus for quantitatively evaluating the degassing efficiency of a mud gas degasser. The difference between this embodiment and embodiment 1 is that the length of the stirring rod 32 located inside the experimental barrel 1 and the length of the air injection channel 11 located inside the experimental barrel 1 are both 3 / 5 of the height of the experimental barrel 1, and the length of the air outlet channel 12 located inside the experimental barrel 1 is 1 / 5 of the height of the experimental barrel 1.

[0082] Example 3

[0083] This embodiment is embodiment 3 of a method and apparatus for quantitatively evaluating the degassing efficiency of a mud gas degasser. The difference between this embodiment and embodiment 1 is that the length of the stirring rod 32 located inside the experimental barrel 1 and the length of the air injection channel 11 located inside the experimental barrel 1 are both 4 / 5 of the height of the experimental barrel 1, and the length of the air outlet channel 12 located inside the experimental barrel 1 is 2 / 5 of the height of the experimental barrel 1.

[0084] Example 4

[0085] This embodiment is embodiment 4 of a method and apparatus for quantitatively evaluating the degassing efficiency of a mud gas degasser. The difference between this embodiment and embodiment 1 is that the length of the stirring rod 32 located inside the experimental barrel 1 and the length of the air injection channel 11 located inside the experimental barrel 1 are both 7 / 10 of the height of the experimental barrel 1, and the length of the air outlet channel 12 located inside the experimental barrel 1 is 3 / 10 of the height of the experimental barrel 1.

[0086] Example 5

[0087] This embodiment is Example 5 of a method and apparatus for quantitatively evaluating the degassing efficiency of a mud gas degasser. The difference between this embodiment and Example 1 is that:

[0088] The specific method for testing the airtightness of experimental container 1 in step one is as follows:

[0089] First, put the lid 2 on the experimental barrel 1 and tighten the buckle. Then, close the second valve 122 on the air outlet channel 12 of the experimental barrel 1, that is, close the air outlet channel 12 of the experimental barrel 1.

[0090] Then, high-pressure air was injected into the test chamber 1 for 3 minutes using a 0.1 MPa air compressor through the air injection channel 11 of the test chamber 1;

[0091] Finally, close the first valve 111 of the gas injection channel 11 on the experimental barrel 1, that is, close the gas injection channel 11 of the experimental barrel 1. Read the pressure value of the experimental barrel 1 through the pressure gauge 121. Read the pressure value inside the experimental barrel 1 again after 40 minutes. If the difference between the pressure values ​​before and after is less than 0.01 MPa, the experimental barrel 1 has good sealing performance and can be used for subsequent operations; otherwise, the experimental barrel 1 has poor sealing performance.

[0092] The specific operation of step three is as follows: the pneumatic drive unit 31 drives the stirring blade 33 to rotate through the stirring rod 32. During the rotation of the stirring blade 33, the mud in the experimental barrel 1 is stirred so that the hydrocarbon gas injected into the experimental barrel 1 is fully dissolved in the mud. During stirring, the stirring speed is 1500 rpm and the stirring time is 40 minutes. After stirring, the experimental barrel 1 is left to stand for 15 minutes.

[0093] Example 6

[0094] This embodiment is Embodiment 6 of a method and apparatus for quantitatively evaluating the degassing efficiency of a mud gas degasser. The difference between this embodiment and Embodiment 1 is that:

[0095] The specific method for testing the airtightness of experimental container 1 in step one is as follows:

[0096] First, put the lid 2 on the experimental barrel 1 and tighten the buckle. Then, close the second valve 122 on the air outlet channel 12 of the experimental barrel 1, that is, close the air outlet channel 12 of the experimental barrel 1.

[0097] Then, high-pressure air was injected into the test chamber 1 for 2 minutes using a 0.1 MPa air compressor through the air injection channel 11 of the test chamber 1;

[0098] Finally, close the first valve 111 of the gas injection channel 11 on the experimental barrel 1, that is, close the gas injection channel 11 of the experimental barrel 1. Read the pressure value of the experimental barrel 1 through the pressure gauge 121. Read the pressure value inside the experimental barrel 1 again after 35 minutes. If the difference between the pressure values ​​before and after is less than 0.01 MPa, the experimental barrel 1 has good sealing performance and can be used for subsequent operations; otherwise, the experimental barrel 1 has poor sealing performance.

[0099] The specific operation of step three is as follows: the pneumatic drive unit 31 drives the stirring blade 33 to rotate through the stirring rod 32. During the rotation of the stirring blade 33, the mud in the experimental barrel 1 is stirred so that the hydrocarbon gas injected into the experimental barrel 1 is fully dissolved in the mud. During stirring, the stirring speed is 1200 rpm and the stirring time is 35 minutes. After stirring, the experimental barrel 1 is left to stand for 13 minutes.

[0100] Test case

[0101] This invention was applied in the degassing efficiency evaluation experiment of GZG degasser in a western exploration area of ​​a certain sea area. The evaluation results of the degassing efficiency correction were consistent with the analysis results of the actual downhole samples. The experimental values ​​of degassing efficiency of methane, ethane, propane and butane were consistent with the analysis data of downhole samples by 90%, which has unique technical advantages and good application effect.

[0102] Application results in a western exploration area of ​​a certain sea area show that the device and method of this invention have a good application effect on the evaluation of degassing efficiency of degassers. The entire operation process is simple, clear and easy for experimental personnel to understand and operate. It can carry out degassing efficiency evaluation for specific types of degassers under different drilling fluid performance conditions. The obtained degassing efficiency evaluation results can significantly improve the interpretation accuracy of gas logging data, which will help the region to obtain more oil and gas discoveries and economic benefits in subsequent oil and gas exploration.

[0103] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for quantitatively evaluating the degassing efficiency of a mud gas degasser, characterized in that: Specifically, the following steps are included: Step 1: Test the airtightness of the experimental container (1); Step 2: Measure the volume V 泥浆 The mud was added into the experimental bucket (1), and the bucket lid (2) was placed on the experimental bucket (1). A quantitative volume V was added. 注气 A specified concentration of hydrocarbon gas is injected into the experimental barrel (1) through the gas injection channel (11); Step 3: Stir the mud in the experimental barrel (1) using the stirring device (3) so that the hydrocarbon gas injected into the experimental barrel (1) in step 2 is fully dissolved in the mud in the experimental barrel (1); Step 4: Open the gas outlet channel (12) of the experimental barrel (1), extract the hydrocarbon gas from the top cavity of the experimental barrel (1), and measure the concentration Cn of the hydrocarbon gas in the top cavity of the experimental barrel (1). 空腔 ; Step 5: Open the lid (2) and use the mud gas degassing device to be evaluated to degas the mud in the experimental bucket (1) to obtain the concentration of hydrocarbon gas Cn in the mud. 泥浆 ; Step 6: Calculate the hydrocarbon gas degassing efficiency of the mud gas degasser to be evaluated; The specific calculation steps for the hydrocarbon gas degassing efficiency of the mud gas degasser to be evaluated in step six are as follows: First, subtract the mud volume V from the total volume V of the experimental bucket. 泥浆 The volume V of the top cavity of the experimental barrel (1) was obtained. 空腔 ; V 空腔 =VV 泥浆 Then, the volume V of the cavity at the top of the experimental barrel (1) is... 空腔 Multiply by the concentration of hydrocarbon gas in the top cavity of the experimental barrel (1), Cn 空腔 The pure volume Vn of hydrocarbon gas in the top cavity of the experimental barrel (1) was obtained. 空腔 ; Vn 空腔 =V 空腔 ×Cn 空腔 Secondly, a quantitative volume V of hydrocarbon gas was injected into the experimental container (1). 注气 Subtract the pure volume of hydrocarbon gas Vn in the top cavity of the experimental barrel (1). 空腔 The pure volume Vn of hydrocarbon gas dissolved in the mud was obtained. 泥浆 ; Vietnam 泥浆 =V 注气 -Vn 空腔 Finally, the concentration of hydrocarbon gases Cn in the mud obtained from the degasser to be evaluated will be... 泥浆 Multiply by the mud volume V 泥浆 Then divide by the pure volume of hydrocarbon gases dissolved in the mud, Vn 泥浆 The hydrocarbon gas degassing efficiency η of the degasser to be evaluated can be obtained. n ; η n =Cn 泥浆 ×V 泥浆 / Vn 泥浆 That is, η n =Cn 泥浆 ×V 泥浆 / {V 注气 -(VV 泥浆 )×Cn 空腔 }。 2. The method for quantitatively evaluating the degassing efficiency of a mud gas degasser according to claim 1, characterized in that: The specific method for testing the airtightness of the experimental barrel (1) in step one is as follows: First, cover the experimental barrel (1) with the lid (2) and close the air outlet channel (12) of the experimental barrel (1); then, use an air compressor to inject high-pressure air into the experimental barrel (1) through the air injection channel (11) of the experimental barrel (1) for 1 to 3 minutes; finally, close the air injection channel (11) of the experimental barrel (1), test the pressure value of the experimental barrel (1), and test the pressure value of the experimental barrel (1) again after 30 to 40 minutes. If the difference between the pressure values ​​before and after is less than 0.01 MPa, the experimental barrel (1) has good airtightness and can be used for subsequent operations; otherwise, the experimental barrel (1) has poor airtightness.

3. The method for quantitatively evaluating the degassing efficiency of a mud gas degasser according to claim 1, characterized in that: In step three, the stirring speed of the stirring device (3) is 1000 rpm to 1500 rpm, and the stirring time is 30 minutes to 40 minutes. After the stirring device (3) has finished stirring, the experimental bucket (1) is left to stand for 10 minutes to 15 minutes.

4. The method for quantitatively evaluating the degassing efficiency of a mud gas degasser according to claim 1, characterized in that: The hydrocarbon gas concentration Cn in the top cavity of the experimental barrel (1) in step four. 空腔 The specific testing method is as follows: Open the gas outlet channel (12) of the experimental barrel (1), connect the gas inlet pipeline of the gas chromatograph to the gas outlet channel (12) of the experimental barrel (1), and continuously test and analyze for at least 10 chromatograph test cycles to finally obtain the hydrocarbon gas concentration Cn in the top cavity of the experimental barrel (1). 空腔 .

5. The method for quantitatively evaluating the degassing efficiency of a mud gas degasser according to claim 1, characterized in that: In step five, the inlet of the mud gas degassing device to be evaluated is placed at the center of the experimental barrel (1) to degas the mud in the experimental barrel (1) until there is no mud in the inlet pipe of the degassing device to be evaluated.

6. A method for quantitatively evaluating the degassing efficiency of a mud gas degasser according to any one of claims 1 to 5, characterized in that: The apparatus used in the method includes an experimental barrel (1) and a lid (2) that can be closed onto the experimental barrel (1); the lid (2) is provided with a metering capacity V. 注气 The test barrel (1) is filled with a specified concentration of hydrocarbon gas through an injection channel (11) and an outlet channel (12) for the hydrocarbon gas to be discharged from the top cavity of the test barrel (1); the barrel cover (2) is also connected to a stirring device (3) for stirring the mud in the test barrel (1).

7. The method for quantitatively evaluating the degassing efficiency of a mud gas degasser according to claim 6, characterized in that: The stirring device (3) includes a driving component (31), a stirring rod (32) and a stirring blade (33); one end of the stirring rod (32) is connected to the output shaft of the driving component (31), and the other end extends into the experimental barrel (1); the stirring blade (33) is located at the end of the stirring rod (32) inside the experimental barrel (1).

8. The method for quantitatively evaluating the degassing efficiency of a mud gas degasser according to claim 6, characterized in that: A first valve (111) for controlling the opening and closing of the gas injection channel (11) is connected to the gas injection channel (11) located outside the experimental barrel (1); the length of the gas injection channel (11) located inside the experimental barrel (1) is 3 / 5 to 4 / 5 of the height of the experimental barrel (1).

9. A method for quantitatively evaluating the degassing efficiency of a mud gas degasser according to claim 6, characterized in that: A pressure gauge (121) and a second valve (122) for controlling the opening and closing of the air outlet channel (12) are connected to the air outlet channel (12) located outside the experimental barrel (1); the pressure gauge (121) is located between the barrel cover (2) and the second valve (122), and the length of the air outlet channel (12) located inside the experimental barrel (1) is 1 / 5 to 2 / 5 of the height of the experimental barrel (1).

Images