Gas logging data comprehensive correction method based on experimental analysis

Abstract

The invention belongs to the technical field of oil fields, mines and the like, and particularly relates to a gas logging data comprehensive correction method based on experimental analysis, which comprises the following steps: collecting engineering parameters, gas logging data and drilling fluid logging data; carrying out statistics on the engineering parameter distribution condition of a hydrocarbon reservoir section in the research area, and extracting standard engineering parameter data by taking a median as a target value; performing engineering parameter theoretical correction on the gas logging data of the target well according to the standard engineering parameter data; according to the drilling fluid logging data distribution condition, a degassing efficiency experiment of specified drilling fluid performance and degasser types is carried out, and hydrocarbon concentration measurement values of different degassers are obtained; and according to the drilling fluid logging data of the target well and the hydrocarbon concentration measurement values of the different degassers, a degassing efficiency correction coefficient is extracted, degassing efficiency correction is carried out on the theoretically corrected gas logging data, and finally corrected gas logging data is obtained. The problem that the explanation precision of an existing method is difficult to improve is solved.

Description

Technical Field

[0001] The present invention belongs to the technical fields of oil fields, mines, etc., and particularly relates to a comprehensive correction method for gas logging data based on experimental analysis. Background Art

[0002] Gas logging is an important technical means for oil exploration and development. By analyzing the gas composition and flow characteristics of the returned drilling fluid at the surface wellhead, the characteristics of hydrocarbon-bearing properties of underground formations can be indirectly inferred, thereby guiding drilling operations and oil and gas exploration and development. However, there are certain errors and interferences in gas logging data, which need to be corrected to better guide oil and gas exploration and development. There are many influencing factors for gas logging data. In terms of engineering operations, there are connections, tripping, coring operations, changes in engineering parameters, changes in drilling fluid properties, and afterflow gas, etc. In terms of geology, there are reservoir heterogeneity, complex fluid properties, and formation energy differences, etc., resulting in difficulties in improving the comparability and interpretation accuracy of gas logging data.

[0003] Many logging practitioners have carried out a large amount of work to achieve effective correction of gas logging data, and the following several methods are introduced:

[0004] For example, starting from the main factors affecting the concentration of broken gas, calculating the unit formation rock volume broken by the drill bit for gas logging data correction, partially realizing the normalization correction of gas data under different drilling conditions;

[0005] For example, aiming at the influence of drilling fluid viscosity on gas logging data, a circulation simulation experiment was carried out, and it was found that when other factors remain unchanged, the gas logging value increases with the increase of drilling fluid viscosity when the funnel viscosity is lower than 60 s (collectively referred to as viscosity hereinafter), and shows the opposite law when it is higher than 60 s viscosity;

[0006] Again, for example, using a self-developed simulation experimental device for gas logging affected by multiple factors, a response experiment of the total hydrocarbon value of gas logging with different drilling fluid densities and viscosities was completed, and it was found that the total hydrocarbon value is the largest when the drilling fluid density is 1.05 g / cm 3 and the viscosity is 60 s;

[0007] In addition, there is also a comparative analysis of gas logging values of the same formation in vertical and horizontal well sections, and it is considered that when the drilling fluid density increases and the viscosity rises, the total hydrocarbon value of gas logging rises, and the influence of drilling fluid density is more significant.

[0008] In summary, the current gas logging correction methods still mainly rely on numerical theoretical calculations, and the experimental simulation corrections are all single-point indoor experiments with drilling fluids of different densities and viscosities, resulting in difficulties in improving the comparability and interpretation accuracy of gas logging data. Summary of the Invention

[0009] The object of the present invention is to provide a comprehensive correction method for gas logging data based on experimental analysis, which solves the problem that it is difficult to improve the interpretation accuracy of existing methods.

[0010] The present invention is realized by the following technical solutions:

[0011] The present invention discloses a comprehensive correction method for gas logging data based on experimental analysis, including the following steps:

[0012] S1. Collect engineering parameters, gas logging data and drilling fluid logging data;

[0013] S2. Statistically study the distribution of engineering parameters in the hydrocarbon-bearing intervals in the study area, and extract standard engineering parameter data with the median as the target value;

[0014] S3. According to the standard engineering parameter data, perform theoretical correction of engineering parameters on the gas logging data of the target well;

[0015] S4. Based on the distribution of drilling fluid logging data, conduct degassing efficiency experiments for specified drilling fluid properties and degasser types to obtain hydrocarbon concentration measurement values of different degassers;

[0016] S5. According to the drilling fluid logging data of the target well and the hydrocarbon concentration measurement values of different degassers obtained in S4, extract the degassing efficiency correction coefficient, and perform degassing efficiency correction on the gas logging data theoretically corrected in S3 to obtain the finally corrected gas logging data.

[0017] Further, in S1, the gas logging data includes the content data of total hydrocarbon, methane, ethane, propane, normal / isobutane and normal / isopentane in the depth domain and the time domain respectively.

[0018] Further, the drilling fluid logging data includes drilling fluid density, viscosity, temperature data and degasser type.

[0019] Further, the engineering parameters include the drilling time, drilling fluid displacement and bit diameter data in the depth domain and the time domain respectively.

[0020] Further, S2 is specifically: determine the hydrocarbon-bearing intervals in the study area, take each interval as an object, calculate the median value of the engineering parameters of all wells in this hydrocarbon-bearing interval, and use the median of this engineering parameter as the standard value during correction to obtain the standard bit diameter, standard drilling time and standard displacement data.

[0021] Further, in S3, the following formula is used to perform theoretical correction of engineering parameters on the gas logging data of the target well:

[0022] C n理 =C n (Rop / Rop 标 )(D b / Db标 )(F low / F low标 );

[0023] In the formula, C n理 is the gas logging data after theoretical correction; C n is the data of total hydrocarbon, methane, ethane, propane, n / i-butane and n / i-pentane content in the depth domain of gas logging data; Rop is the original drilling time; Rop 标 is the standard drilling time; D b is the original bit diameter; D b标 is the standard bit diameter; F low is the original drilling fluid displacement; F low标 is the standard drilling fluid displacement.

[0024] Furthermore, S4 is specifically as follows:

[0025] Prepare drilling fluid samples and saturated injection hydrocarbon gases according to the drilling fluid performance range in the study area, and use different degassers to conduct degassing analysis simultaneously to obtain the hydrocarbon concentration measurement values of different degassers.

[0026] Furthermore, in S5, according to the drilling fluid logging data of the target well and the hydrocarbon concentration measurement values of different degassers obtained in S4, extract the degassing efficiency correction coefficient, and the specific expression is:

[0027] η n = C 脱 / C VMS ;

[0028] In the formula, η n is the degassing efficiency correction coefficient; C 脱 is the hydrocarbon concentration measured by the degasser used in gas logging; C VMS is the hydrocarbon concentration measured by the VMS degasser.

[0029] Furthermore, in S5, based on the degassing efficiency correction coefficient, perform degassing efficiency correction on the theoretically corrected gas logging data obtained in S3, and the expression is:

[0030] C n校 = C n理 η n ;

[0031] In the formula, C n校 is the finally corrected gas logging data, C n理 is the theoretically corrected gas logging data, and η n is the degassing efficiency correction coefficient.

[0032] Furthermore, the engineering parameters, gas logging data, and drilling fluid logging data are extracted from the logging data in the study area. The specific extraction method is as follows: collect the logging data in the study area, and extract the engineering parameters, gas logging data, and drilling fluid logging data from the real-time monitoring data of the comprehensive logging instrument of a single well.

[0033] Compared with the prior art, the present invention has the following beneficial technical effects:

[0034] The present invention discloses a comprehensive correction method for gas logging data based on experimental analysis. By removing the abnormal gas logging values during pump shutdown, statistically analyzing the distribution of engineering parameters in the main intervals in the area, extracting the standard bit diameter, standard drilling time, and standard displacement data with the median as the target value respectively as the basic parameters for theoretical correction; for the bit diameter, standard drilling time, and standard displacement, theoretically correct the gas logging data with the actual value and the target value to obtain the preliminary corrected result of the gas logging data; design the degassing efficiency experiment under different drilling fluid properties and degasser types to obtain the law of gas logging data changing with drilling fluid properties and degasser types; extract the drilling fluid property parameters and degasser types in the actual well data, and correct the preliminary corrected result of the gas logging data according to the corresponding degassing efficiency to obtain the final corrected result of the gas logging data. The present invention completes the comprehensive correction of gas logging data by performing engineering parameter theoretical correction after removing outliers from the original gas logging data and combining the experimental results of degassing efficiency for different drilling fluid properties and degasser types. This correction technology uses the basic parameters collected during the logging operation as a means to effectively correct gas logging data under different engineering conditions, and truly improves the vertical and horizontal comparability of gas logging data, which is an effective method to improve the interpretation accuracy of gas logging data. Brief Description of the Drawings

[0035] Figure 1 is a flowchart of a comprehensive correction method for gas logging data based on experimental analysis of the present invention;

[0036] Figure 2 is the correction result of a typical well. Detailed Description of the Invention

[0037] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0038] The components described and illustrated in the accompanying drawings and embodiments of the present invention can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present invention provided in the following drawings is not intended to limit the scope of the claimed invention, but merely represents a selected embodiment of the present invention. Based on the accompanying drawings and embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0039] It should be noted that the term "comprising", "including" or any other variant is intended to cover non-exclusive inclusion, such that a process, element, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to the process, element, method, article or device.

[0040] The present invention provides a comprehensive correction method for gas logging data based on experimental analysis. By removing the abnormal gas logging values during pump shutdown, theoretical correction of the gas logging data is performed for the bit diameter, standard drilling time, and standard displacement using the actual values and target values. The degassing efficiency correction is carried out by using the degassing efficiency experiments under different drilling fluid properties and degasser types to obtain the final corrected result of the gas logging data.

[0041] As Figure 1 shown, the present invention discloses a comprehensive correction method for gas logging data based on experimental analysis, including the following specific steps:

[0042] S1. Collect engineering parameters, gas logging data, and drilling fluid logging data;

[0043] S2. Statistically analyze the distribution of engineering parameters in the hydrocarbon-bearing intervals in the study area, and extract the standard bit diameter, standard drilling time, and standard displacement data with the median as the target value;

[0044] S3. According to the standard bit diameter, standard drilling time, and standard displacement data, perform theoretical correction of the engineering parameters for the gas logging data of the target well;

[0045] S4. Based on the distribution of the drilling fluid logging data, conduct degassing efficiency experiments for the specified drilling fluid properties and degasser types to obtain the hydrocarbon concentration measurement values of different degassers;

[0046] S5. According to the drilling fluid logging data of the target well and the hydrocarbon concentration measurement values of different degassers obtained in S4, extract the degassing efficiency correction coefficient, and perform degassing efficiency correction on the theoretically corrected gas logging data.

[0047] In S1, the engineering parameters include the drilling time, drilling fluid displacement, and bit diameter data in the depth domain and time domain respectively;

[0048] Gas logging data include the content data of total hydrocarbons, methane, ethane, propane, n / i-butane, and n / i-pentane in the depth domain and time domain respectively;

[0049] Drilling fluid logging data include drilling fluid density, viscosity, temperature data, and degasser type.

[0050] In S1, engineering parameters, gas logging data, and drilling fluid logging data are extracted from the logging data in the study area. The specific extraction method is as follows: collect the logging data in the study area, and extract engineering parameters, gas logging data, and drilling fluid logging data from the real-time monitoring data of the comprehensive logging instrument of a single well.

[0051] In S2, statistically analyze the distribution of engineering parameters in the main intervals within the area, and extract the standard bit diameter, standard drilling time, and standard displacement data respectively with the median as the target value. Specifically, it includes:

[0052] Determine the hydrocarbon-bearing intervals in the study area. Take each interval as the object, and obtain the median value of the target parameters of all wells in this interval. The target parameters are bit diameter, drilling time, and displacement. Use the median of this parameter as the standard value for correction.

[0053] In S3, perform theoretical correction of engineering parameters on the gas logging data of the target well according to the standard bit diameter, standard drilling time, and standard displacement data. Specifically, it includes:

[0054] According to the actual values and standard values of the bit diameter, drilling time, and displacement data, use the following formula for theoretical correction of engineering parameters:

[0055] C n理 =C n (Rop / Rop 标 )(D b / D b标 )(F low / F low标 )

[0056] In the formula, C n理 is the gas logging data after theoretical correction of engineering parameters, %; C n is the original gas logging data, %; Rop is the original drilling time, minutes / meter; Rop 标 is the standard drilling time, minutes / meter; D b is the original bit diameter, mm; D b标 is the standard bit diameter, mm; F low is the original drilling fluid displacement, liters / minute; F low标 is the standard drilling fluid displacement, liters / minute.

[0057] In S4, conduct degassing efficiency experiments under different drilling fluid properties and degasser conditions, including:

[0058] Configure drilling fluid samples and saturated injection hydrocarbon gases according to the performance range of the drilling fluid in the study area, and use different degassers to conduct degassing analysis simultaneously to obtain the measured values of hydrocarbon concentrations of different degassers;

[0059] In S5, according to the actual drilling fluid performance and degasser type of the target well, extract the degassing efficiency correction coefficient, specifically:

[0060] Extract the degassing efficiency correction coefficient, and obtain the degassing efficiency correction coefficient of different degassers using the following formula:

[0061] η n = C 脱 / C VMS

[0062] In the formula, η n is the degassing efficiency correction coefficient of hydrocarbon components under specific drilling fluid performance conditions, %; C 脱 is the hydrocarbon concentration measured by the degasser used in gas logging, %; C VMS is the hydrocarbon concentration measured by the VMS degasser, %. VMS is a thermal vacuum distillation degasser.

[0063] Use the following formula to correct the degassing efficiency of the gas logging data after theoretical correction:

[0064] C n校 = C n理 η n ;

[0065] In the formula, C n校 is the finally corrected gas logging data, C n理 is the gas logging data after theoretical correction, and η n is the degassing efficiency correction coefficient.

[0066] The present invention provides a method for correcting gas logging data. By removing the abnormal gas logging values during the pump stop period, statistically analyzing the distribution of engineering parameters in the main intervals in the area, extracting the standard bit diameter, standard drilling time, and standard displacement data with the median as the target value respectively as the basic parameters for theoretical correction; for the bit diameter, standard drilling time, and standard displacement, theoretically correct the gas logging data with the actual value and the target value to obtain the preliminary corrected result of the gas logging data; design a degassing efficiency experiment under different drilling fluid performance and degasser type conditions to obtain the law of the change of gas logging data with the drilling fluid performance and degasser type; extract the drilling fluid performance parameters and degasser type in the actual well data, and correct the preliminary corrected result of the gas logging data according to the corresponding degassing efficiency to obtain the finally corrected result of the gas logging data.

[0067] The features and performance of the present invention will be further described in detail below in conjunction with the embodiments.

[0068] The present invention has been applied to the correction of gas logging data in the Tarim Basin. Under the complex application background of complex wellbore structures, significant differences in drilling techniques and penetration rates, and various types of degassers, pretreatment of gas logging data was first carried out, engineering parameter correction was performed, and at the same time, experimental evaluations of the degassing efficiency of different drilling fluid properties and degasser types were conducted. The gas logging data was finally corrected according to the degassing efficiency correction model established through experiments. Figure 1 ) Before correction, the display value of the gas logging curve in the deep tight formation section was relatively low. After correction, the peak region of the gas logging curve was in good agreement with the gas layer. Figure 2 ) This verified the unique technical advantages and obvious application effects of this method.

[0069] Application in the Tarim Basin shows that the comprehensive correction technology for gas logging data based on experimental analysis has good correction effects under complex logging conditions with significant differences in engineering parameters and various types of degassers. This method is not affected by objective factors such as changes in drilling process conditions and different types of logging degassers, and can effectively correct gas logging data during logging operations under complex drilling conditions. This application effect effectively improves the interpretation accuracy of gas logging data in this region, providing assistance for the in-depth application of gas logging technology and the reserve increase and production increase of the operating party.

[0070] 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 above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific embodiments of the present invention, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A comprehensive correction method for gas logging data based on experimental analysis, characterized in that, It includes the following steps: S1. Collect engineering parameters, gas logging data, and mud logging data; S2. Statistically study the distribution of engineering parameters in the hydrocarbon-bearing intervals in the study area, and extract standard engineering parameter data with the median as the target value; S3. According to the standard engineering parameter data, conduct theoretical correction of engineering parameters for the gas logging data of the target well; S4. Based on the distribution of mud logging data, carry out degassing efficiency experiments on the specified mud properties and degasser types to obtain hydrocarbon concentration measurement values of different degassers; S5. According to the mud logging data of the target well and the hydrocarbon concentration measurement values of different degassers obtained in S4, extract the degassing efficiency correction coefficient, and conduct degassing efficiency correction on the gas logging data theoretically corrected in S3 to obtain the finally corrected gas logging data.

2. The comprehensive correction method for gas logging data based on experimental analysis according to claim 1, characterized in that In S1, the gas logging data includes the content data of total hydrocarbon, methane, ethane, propane, normal / isobutane, and normal / isopentane in the depth domain and time domain respectively.

3. The comprehensive correction method for gas logging data based on experimental analysis according to claim 1, characterized in that The mud logging data includes mud density, viscosity, temperature data, and degasser type.

4. A comprehensive calibration method for gas logging data based on experimental analysis according to claim 1, characterized in that, The engineering parameters include drilling time, mud displacement, and bit diameter data in the depth domain and time domain respectively.

5. A comprehensive correction method for gas logging data based on experimental analysis according to claim 4, characterized in that, Specifically, S2 is as follows: Determine the hydrocarbon-bearing intervals in the study area. For each interval, obtain the median value of the engineering parameters of all wells in this hydrocarbon-bearing interval, and use the median of the engineering parameters as the standard value for correction to obtain standard bit diameter, standard drilling time, and standard displacement data.

6. The comprehensive calibration method of gas logging data based on experimental analysis according to claim 5, characterized in that In S3, the following formula is used to conduct theoretical correction of engineering parameters for the gas logging data of the target well: C n理 = C n (Rop / Rop 标 )(D b / D b标 )(F low / F low标 ); Where, C n理 is the gas logging data after theoretical correction; C n is the data of total hydrocarbons, methane, ethane, propane, n / i-butane and n / i-pentane contents in the depth domain of the gas logging data; Rop is the original drilling time; Rop 标 is the standard drilling time; D b is the original bit diameter; D b标 is the standard bit diameter; F low is the original drilling fluid displacement; F low标 is the standard drilling fluid displacement.

7. A comprehensive correction method for gas logging data based on experimental analysis according to claim 1, characterized in that Specifically, S4 is as follows: Configure mud samples and saturated injection of hydrocarbon gases according to the mud property intervals in the study area, and use different degassers to conduct degassing analysis simultaneously to obtain hydrocarbon concentration measurement values of different degassers.

8. A comprehensive correction method for gas logging data based on experimental analysis according to claim 1, characterized in that In S5, according to the mud logging data of the target well and the hydrocarbon concentration measurement values of different degassers obtained in S4, extract the degassing efficiency correction coefficient, and the specific expression is: η n = C 脱 / C VMS ; Where, η n is the degassing efficiency correction coefficient; C 脱 is the hydrocarbon concentration measured by the degasser used in gas logging; C VMS is the hydrocarbon concentration measured by the VMS degasser.

9. A comprehensive calibration method for gas logging data based on experimental analysis according to claim 8, characterized in that, In S5, based on the degassing efficiency correction coefficient, conduct degassing efficiency correction on the gas logging data theoretically corrected in S3, and the expression is: C n校 = C n理 η n ; Where, C n校 is the gas logging data after final correction, C n理 is the gas logging data after theoretical correction, and η n is the degassing efficiency correction coefficient.

10. A comprehensive calibration method for gas logging data based on experimental analysis according to claim 1, characterized in that, The engineering parameters, gas logging data, and mud logging data are extracted from the logging data in the study area. Specifically, the extraction method is as follows: Collect the logging data in the study area, and extract the engineering parameters, gas logging data, and mud logging data from the real-time monitoring data of the comprehensive logging instrument of a single well.

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