Marine facies shale gas reservoir fluid apparent resistivity backstepping judgment method and device and application

Abstract

The invention discloses a marine facies shale gas reservoir fluid apparent resistivity backstepping judgment method and device and application, and belongs to the technical field of shale gas resource evaluation.The method comprises the steps that induction logging data of a single well is collected, deep and shallow exploration depth resistivity curves are obtained, and a deep exploration curve and a shallow exploration curve are selected; establishing a relational expression of the deep detection resistivity Rd and the shallow detection resistivity Rs according to the related data obtained in the previous step, and solving the apparent resistivity R flow of the fluid; the fluid apparent resistivity R flow obtained in the previous step is used for fluid judgment, meanwhile, the invention further discloses a judgment device, computer equipment and a computer readable storage medium related to the method, the single well fluid judgment result can be rapidly obtained, and the accuracy of the judgment result is high.

Description

Technical Field

[0001] The present invention relates to the technical field of shale gas resource evaluation, and in particular to a method, device and application for reversely determining apparent resistivity of marine shale gas reservoir fluid. Background Art

[0002] With the progress of shale gas exploration and development in the Sichuan Basin over the past decade, most shale gas companies are in the stage of large-scale production, efficient production, and stable production succession. Complex wells with low resistance and low production are frequently drilled in the production areas, and the successor blocks are gradually moving towards complex structural areas. The fluid properties in different parts of the same structure are obviously different. How to quickly and effectively identify the fluid properties is an urgent problem that needs to be solved.

[0003] Resistivity is one of the key indicator parameters for evaluating whether a shale gas reservoir contains gas. Compared with the deep and shallow dual lateral logging method, the array induction logging method is based on curves of multiple resolutions and detection depths, which not only improves the accuracy of stratigraphic section division, but also improves the accuracy of interpretation and evaluation. The main means of obtaining resistivity in shale gas reservoirs is array induction logging. Induction logging forms induced eddies in the formation to measure the resistivity of the surrounding rock. The invasion of mud filtrate in the reservoir makes the induction resistivity at different detection depths have different response characteristics. At the same time, different reservoir fluid properties also have different effects on the differences in array induction resistivity responses. Generally speaking, the larger the apparent resistivity value obtained, the higher the calculated gas saturation, and it can basically be concluded that the well can produce gas.

[0004] However, in recent years, shale gas exploration and development has gradually expanded to complex basin-mountain structural belts. The structural transformation in this area is strong, the natural fractures are complex, the organic matter maturity is relatively high, and the resistivity of the surrounding rock is reduced due to multiple factors. The obtained apparent resistivity is low. The traditional method of calculating gas saturation by apparent resistivity cannot effectively determine whether it contains gas. And it has been verified by tests that some low-resistance wells do have good gas production capacity. It can be seen that how to eliminate the influence of surrounding rock resistivity and quickly determine whether a single well contains gas by apparent resistivity is very critical to efficient production. Summary of the invention

[0005] At present, in the field of oil and gas, lateral logging is mostly used in the early stage. This method is similar to the connection method of series circuit and the measurement of position or components. In recent years, the induction logging used in shale gas exploration and development is similar to parallel circuit, but in the application evaluation of the apparent resistivity value obtained by logging, the inherent thinking of the early series is still used, that is, the apparent resistivity obtained by logging is basically equal to the sum of the surrounding rock resistivity, drilling fluid resistivity, and fluid resistivity. At the same time, marine sedimentary shale has a large deposition thickness and stable distribution. The surrounding rock resistivity of the reservoir in the same area will not change much. Therefore, the high apparent resistivity value obtained by logging in a single well in the same reservoir section in the same area means that the fluid resistivity is high, indicating that the well contains gas.

[0006] The inventor of this solution found that such an evaluation model ignores the changes in the logging methods and equipment currently used, and uses the inherent series thinking on parallel equipment, which directly leads to the misjudgment of many wells. Especially when drilling low-resistance wells with logging apparent resistivity lower than 20Ω.m, there is no effective method to identify the fluid properties. Judging from the resistivity alone, it is often believed that the well produces water, and the auxiliary core gas content and gas saturation cannot be accurately judged. The overall accuracy of identifying the fluid properties of the reservoir in low-resistance wells is not high, only 69.3%.

[0007] The purpose of the present invention is to provide a method for inversely determining the apparent resistivity of marine shale gas reservoir fluids. By calculating the apparent resistivity of shale gas reservoir fluids, a method for determining fluid properties is established. This method can quickly identify whether a single well can produce gas, which has urgent theoretical guiding significance for shale gas production.

[0008] The present invention is achieved through the following technical solutions:

[0009] The method for inversely determining the apparent resistivity of marine shale gas reservoir fluid includes the following steps:

[0010] S1: Collect induction logging data of a single well, obtain deep and shallow detection depth resistivity curves, and select deep detection curve and shallow detection curve;

[0011] S2: Based on the relevant data obtained in step S1, establish the deep detection resistivity R d , shallow detection resistivity R s The relationship between the fluid apparent resistivity R 流 ;

[0012] S3: Fluid apparent resistivity R obtained in step S2 流 Perform fluid identification.

[0013] Furthermore, in step S2, the surrounding rock resistivity R of a single well is obtained. 围 , drilling fluid resistivity R 钻 , deep detection resistivity R d , shallow detection resistivity R s The fluid apparent resistivity R is obtained by satisfying the following relations (1) and (2): 流 :

[0014]

[0015]

[0016] In the formula, R d ——deep detection resistivity, Ω.m;

[0017] R s——shallow detection resistivity, Ω.m;

[0018] R 围 ——Resistivity of surrounding rock, Ω.m;

[0019] R 钻 ——Drilling fluid resistivity, Ω.m;

[0020] R 流 ——Fluid apparent resistivity, Ω.m.

[0021] Further, in step S2, the fluid apparent resistivity R 流 The following relationship (3) is satisfied. Considering that under the condition of oil-based mud, R s , R d The value is affected by many factors. The denominator in formula (3) takes the absolute value:

[0022]

[0023] Further, in step S3, the fluid apparent resistivity R 流 When the fluid apparent resistivity is high, it is considered that the well is producing gas. When the fluid apparent resistivity is low, it is considered that the well is producing water. Specifically, when the fluid apparent resistivity R 流 When the resistivity of the fluid exceeds the maximum resistivity of the water layer in the regional oil test, the well is judged to be gas producing; when the fluid apparent resistivity R 流 When the resistance is lower than the maximum resistance of the test water layer, the well is considered to produce water.

[0024] Furthermore, in step S3, since the distribution of marine shale in the same reservoir section in the same area is stable and the resistivity has no obvious change, they have been offset in the calculation, and there is no need to obtain the surrounding rock resistivity R 围 The actual measured value.

[0025] Furthermore, in step S1, the deep detection depth resistivity curve and the shallow detection depth resistivity curve are obtained by measuring with an induction logging instrument.

[0026] An application of the aforementioned method for inversely judging the apparent resistivity of marine shale gas reservoir fluids is characterized in that it is used to identify the fluid properties of low-resistance wells with a well logging apparent resistivity lower than 20Ω.m when drilling.

[0027] A device for back-calculating and distinguishing the apparent resistivity of a marine shale gas reservoir fluid, the device being used to implement any of the above-mentioned methods for back-calculating and distinguishing the apparent resistivity of a marine shale gas reservoir fluid, the device comprising: a data acquisition module, a data analysis module and a distinguishing and evaluating module,

[0028] The data acquisition module is used to obtain the deep and shallow detection depth resistivity curves of a single well;

[0029] The data analysis module is used to select the deep detection curve and the shallow detection curve, and establish the deep detection resistivity R d , shallow detection resistivity R s The relationship between the fluid apparent resistivity R 流 ;

[0030] The discrimination and evaluation module is used to calculate the apparent resistivity R of the fluid in a single well. 流 Compare it with the preset value and then determine whether the well is a gas producing well or a water producing well.

[0031] A computer device comprises a memory, a processor and a computer program stored in the memory and executable in the processor, wherein when the processor executes the computer program, the above method steps are implemented.

[0032] A computer-readable storage medium stores a computer program, and when the computer program is executed in a computer processor, the method described above is implemented.

[0033] The inventor of this solution tested this method on 34 known wells, and compared the identification results with the oil test results. The coincidence rate reached 96.8%, which shows that the accuracy of single well fluid identification has been significantly improved.

[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0035] 1. In the present invention, the limited data of well logging is effectively utilized. Based on the principle of induction well logging, the inherent thinking method of resistivity for fluid identification is changed. The apparent resistivity obtained by single well logging is not the simple sum of surrounding rock resistivity, drilling fluid resistivity and fluid resistivity. It is impossible to directly determine the single well fluid properties by the value. The method of using the parallel resistance formula to obtain the fluid apparent resistivity to identify the fluid properties has been tested on 34 known wells. The test results are consistent with the oil test at a rate of 96.8%, which significantly improves the accuracy of single well fluid identification.

[0036] 2. In the present invention, the method has the characteristics of high timeliness and low cost. It only uses logging data and does not need to wait for core experiment data, which can save coring and related analysis and testing costs. This method effectively reduces costs and increases efficiency, and achieves efficient development. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a flowchart of the present invention. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0039] Example 1

[0040] like Figure 1 As shown, the present invention provides a method for inversely judging the apparent resistivity of marine shale gas reservoir fluid, which relates to the technical field of shale gas resource evaluation, and comprises the following steps:

[0041] S1: Collect induction logging data of a single well. Induction logging can measure deep and shallow detection depth resistivity curves. Select the deep detection curve and use R d Indicates; Select the shallow detection curve and use R s express.

[0042] S2: Use the relevant data obtained in step S1 to establish the deep detection resistivity R d , shallow detection resistivity R s The equation group is used to calculate the apparent resistivity of the fluid.

[0043] Induction logging is based on the principle of electromagnetic induction. When the sensor coil in the induction logging instrument passes through the formation, the conductive medium in the formation will affect the inductance element, similar to the effect of resistance on inductance in a parallel circuit. Assuming that the sensor coil in the induction logging instrument is regarded as an inductance element, the conductive medium in the formation is equivalent to the resistance element in the parallel circuit.

[0044] The deep detection resistivity R of the reservoir section has been obtained through step S1. d , shallow detection resistivity R s ; where R d It is mainly affected by the resistivity of surrounding rock, invading drilling fluid and fluid. s It is basically affected by the resistivity of the surrounding rock and the intrusive drilling fluid. In view of the relatively stable lithology of marine sedimentary shale, it can be assumed that the resistivity of the surrounding rock at the same depth of a single well is basically the same.

[0045] That is, in this step, the surrounding rock resistivity R of a single well is obtained. 围 , drilling fluid resistivity R 钻 , the deep detection resistivity R of the reservoir section is established through the parallel resistance formula d , shallow detection resistivity R s The apparent resistivity R of the fluid can be obtained by using equations (1) and (2). 流 :

[0046]

[0047]

[0048] In the formula, R d ——deep detection resistivity, Ω.m;

[0049] R s ——shallow detection resistivity, Ω.m;

[0050] R 围 ——Resistivity of surrounding rock, Ω.m;

[0051] R 钻 ——Drilling fluid resistivity, Ω.m;

[0052] R 流 ——Fluid apparent resistivity, Ω.m.

[0053] According to equations (1) and (2), we can get R 流 , under oil-based mud conditions, R s , R d The value may be affected by many factors. The denominator is taken as an absolute value, that is, the fluid apparent resistivity R 流 The following relationship (3) is satisfied:

[0054]

[0055] S3: The fluid is identified by the fluid apparent resistivity obtained in step S2. If the fluid apparent resistivity is high, it is determined that the well is producing gas, and if the fluid apparent resistivity is low, it is considered that the well is producing water. 流 When the resistivity of the fluid exceeds the maximum resistivity of the water layer in the regional oil test, the well is judged to be gas producing; when the fluid apparent resistivity R 流 When the resistance is lower than the maximum resistance of the test water layer, the well is considered to produce water.

[0056] In this embodiment, in order to further verify the reliability of this method, this method is used to further identify and verify the fluid properties of known wells. First, according to the method in step S1, the induction resistance data of 8 wells are collected to extract the deep detection resistivity R of the reservoir section. d , shallow detection resistivity data R s , relevant data are shown in Table 1.

[0057] Table 1

[0058] well name <![CDATA[R d ]]> <![CDATA[R s ]]> well name <![CDATA[R d ]]> <![CDATA[R s ]]> well name <![CDATA[R d ]]> <![CDATA[R s ]]> well name <![CDATA[R d ]]> <![CDATA[R s ]]> N33 1.4 1.1 N17 28.7 29.7 Y3 16.2 15.6 N13 72.1 66.5 N33 1.5 1.2 N17 24.1 25.2 Y3 15.4 14.9 N13 64.3 59.2 N33 1.6 1.3 N17 22.2 23.2 Y3 13.7 13.5 N13 55.4 51.1 N33 1.7 1.3 N17 19.8 20.5 Y3 13.2 13.1 N13 45.9 42.6 N33 1.7 1.4 N17 18.9 19.7 Y3 13.1 12.9 N13 39.7 37.2 N33 1.7 1.4 N17 18.8 19.7 Y3 13.9 13.3 N13 36.0 34.1 N33 1.7 1.3 N17 18.6 19.7 Y3 14.2 13.2 N13 34.8 33.5 N33 1.7 1.3 N17 18.2 19.6 Y3 13.3 11.7 N13 36.1 35.3 N33 1.7 1.3 N17 17.8 19.4 Y3 10.1 8.6 N13 40.0 39.5 N33 1.7 1.3 N17 16.2 18.1 Y3 8.3 7.0 N13 47.2 47.0 N33 1.7 1.3 N17 13.0 15.1 Y3 5.6 4.9 N13 48.3 48.7 N33 1.6 1.3 N17 11.1 13.1 Y3 4.5 4.2 N13 43.6 44.4 N33 1.6 1.2 N17 7.7 9.3 Y3 4.4 4.1 N13 34.4 35.4 N33 1.5 1.2 N17 6.7 7.9 Y3 4.6 4.3 N13 23.6 24.8 N33 1.5 1.2 N17 5.9 6.7 Y3 4.9 4.6 N13 17.4 18.2 N33 1.5 1.1 N17 6.3 7.0 Y3 5.7 5.1 N13 16.8 17.5 N33 1.5 1.1 N17 6.9 7.7 Y3 6.1 5.4 N13 20.2 20.8 N33 1.5 1.1 N17 8.4 9.5 Y3 6.2 5.5 N13 29.7 30.3 N33 1.6 1.1 N17 9.3 10.8 Y3 6.3 5.8 N13 44.1 44.7 N18 0.2 0.1 N42 2.4 2.1 N11 23.7 25.4 Y07 15.4 14.0 N18 0.2 0.2 N42 2.3 2.0 N11 24.6 26.4 Y07 13.2 12.4 N18 0.2 0.2 N42 2.2 1.8 N11 25.9 27.5 Y07 12.6 12.3 N18 0.2 0.2 N42 2.0 1.7 N11 26.6 28.0 Y07 12.8 12.8 N18 0.2 0.1 N42 2.0 1.7 N11 26.3 27.3 Y07 13.3 13.5 N18 0.1 0.1 N42 2.0 1.7 N11 26.4 27.2 Y07 13.6 13.9 N18 0.1 0.1 N42 2.0 1.7 N11 27.6 28.4 Y07 13.4 13.7 N18 0.1 0.1 N42 2.1 1.7 N11 28.7 29.4 Y07 13.0 13.2 N18 0.1 0.1 N42 2.1 1.8 N11 28.9 29.5 Y07 12.7 12.9 N18 0.1 0.1 N42 2.2 1.9 N11 28.6 29.0 Y07 13.0 13.1 N18 0.1 0.1 N42 2.3 2.0 N11 27.8 28.1 Y07 13.9 13.9 N18 0.1 0.1 N42 2.3 2.0 N11 26.2 26.4 Y07 14.9 14.9 N18 0.1 0.1 N42 2.3 2.0 N11 24.7 24.9 Y07 15.6 15.6 N18 0.1 0.1 N42 2.3 2.0 N11 23.3 23.5 Y07 15.8 15.8 N18 0.1 0.1 N42 2.5 2.1 N11 21.9 22.1 Y07 15.6 15.5 N18 0.1 0.1 N42 2.7 2.1 N11 20.8 21.1 Y07 15.4 15.1 N18 0.1 0.1 N42 2.8 2.2 N11 20.8 21.1 Y07 15.2 14.9 N18 0.1 0.1 N42 2.8 2.2 N11 22.0 22.3 Y07 15.2 14.8 N18 0.1 0.1 N42 2.8 2.3 N11 23.4 23.9 Y07 15.2 14.8

[0059] Then, according to the method in step S2, the data in Table 1 is substituted into formula (3) for calculation to obtain the apparent resistivity of the fluid at different depths in the reservoir section of each well. The results are shown in Table 2.

[0060] Table 2

[0061] well name <![CDATA[R 流 ]]> well name <![CDATA[R 流 ]]> well name <![CDATA[R 流 ]]> well name <![CDATA[R 流 ]]> N33 6.1 N17 850.3 Y3 391.6 N13 857.6 N33 5.9 N17 530.1 Y3 410.0 N13 744.4 N33 5.9 N17 512.3 Y3 791.6 N13 652.8 N33 6.0 N17 543.4 Y3 1344.1 N13 585.6 N33 6.2 N17 457.8 Y3 832.5 N13 581.9 N33 6.2 N17 403.5 Y3 278.1 N13 652.6 N33 6.3 N17 324.9 Y3 189.0 N13 879.8 N33 6.2 N17 261.7 Y3 101.0 N13 1503.6 N33 6.0 N17 228.3 Y3 58.0 N13 3220.9 N33 5.8 N17 157.1 Y3 46.4 N13 9687.9 N33 5.7 N17 95.0 Y3 40.8 N13 6745.6 N33 5.6 N17 72.3 Y3 54.0 N13 2467.3 N33 5.8 N17 46.4 Y3 64.5 N13 1153.4 N33 5.8 N17 42.3 Y3 75.8 N13 491.5 N33 5.7 N17 47.5 Y3 70.0 N13 383.3 N33 5.2 N17 63.8 Y3 54.8 N13 422.7 N33 4.9 N17 70.5 Y3 49.7 N13 746.3 N33 4.5 N17 73.1 Y3 52.5 N13 1609.2 N33 4.4 N17 68.4 Y3 77.6 N13 3441.0 N18 1.6 N42 19.7 N11 345.7 Y07 148.9 N18 1.0 N42 14.2 N11 379.2 Y07 207.5 N18 0.8 N42 11.9 N11 429.3 Y07 476.6 N18 0.8 N42 11.1 N11 524.9 Y07 27477.6 N18 0.9 N42 11.3 N11 686.0 Y07 819.3 N18 1.3 N42 11.6 N11 860.9 Y07 641.9 N18 2.5 N42 10.3 N11 1061.8 Y07 670.9 N18 13.1 N42 9.5 N11 1291.2 Y07 752.6 N18 12.0 N42 10.7 N11 1623.6 Y07 861.6 N18 11.1 N42 13.3 N11 2239.2 Y07 1130.8 N18 5.2 N42 15.3 N11 3178.5 Y07 2033.0 N18 3.4 N42 15.2 N11 3758.6 Y07 7656.0 N18 3.4 N42 14.5 N11 3473.5 Y07 12175.8 N18 2.3 N42 13.9 N11 2752.3 Y07 4532.9 N18 2.3 N42 12.2 N11 2167.3 Y07 2073.2 N18 1.4 N42 10.6 N11 1747.8 Y07 1026.0 N18 1.2 N42 10.5 N11 1499.2 Y07 670.6 N18 1.1 N42 11.3 N11 1433.9 Y07 576.4 N18 1.2 N42 12.1 N11 1377.2 Y07 597.9

[0062] Then, according to the fluid apparent resistivity R of the eight wells obtained in step S2, 流 The maximum resistance of the water layer in the oil test area is 50Ω.m. The apparent resistivity of the fluid in wells N33, N18, and N42 is R 流Less than 50Ω.m, which is a low value, it is determined that 3 wells are producing water; the remaining 5 wells have fluid apparent resistivity R 流 The value is generally greater than 50Ω.m, showing a high value, which can be determined as a gas-producing well. Tests have confirmed that wells N33, N18, and N42 all produce water, and wells N17, Y3, and N13 are all gas wells.

[0063] Furthermore, the present invention also proposes a device for reversely estimating apparent resistivity of marine shale gas reservoir fluid, which is used to implement the above-mentioned reverse estimating method for apparent resistivity of marine shale gas reservoir fluid. The device comprises: a data acquisition module, a data analysis module and a discrimination evaluation module.

[0064] The data acquisition module is used to obtain the deep and shallow detection depth resistivity curves of a single well;

[0065] The data analysis module is used to select the deep detection curve and the shallow detection curve, and establish the deep detection resistivity R d , shallow detection resistivity R s The relationship between the fluid apparent resistivity R 流 ;

[0066] The discrimination and evaluation module is used to calculate the apparent resistivity R of the fluid in a single well. 流 Compare it with the preset value and then determine whether the well is a gas producing well or a water producing well.

[0067] Furthermore, the present invention also proposes a computer device, including a memory, a processor, and a computer program stored in the memory and executable in the processor, wherein the above method steps can be implemented when the processor executes the computer program.

[0068] Furthermore, the present invention also proposes a computer-readable storage medium, which stores a computer program. When the computer program is executed in a computer processor, it implements the above-mentioned method for reverse inference of apparent resistivity of fluid in marine shale gas reservoirs, and can quickly determine whether other wells in the same area are gas wells or water wells.

[0069] The method for inversely judging the apparent resistivity of marine shale gas reservoir fluid is suitable for identifying the properties of marine shale gas reservoir fluid, and is particularly suitable for identifying the properties of fluid in low-resistance wells with a well logging apparent resistivity lower than 20Ω.m. In the prior art, methods such as the Archie formula directly use the apparent resistivity value obtained by the logging instrument to calculate the water saturation, and then calculate the gas saturation, but do not consider the influence of factors such as surrounding rock on the resistivity, which will lead to the problem that the gas saturation calculated in some low-resistance wells cannot truly reflect the fluid properties, and is not suitable for the identification of fluid properties in low-resistance wells with an apparent resistivity lower than 20Ω.m. This method can solve this problem well.

[0070] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for inferring apparent resistivity of marine shale gas reservoir fluid, characterized in that: The following steps are involved: S1: Collect induction logging data of a single well, obtain deep and shallow detection depth resistivity curves, and select deep detection curve and shallow detection curve; S2: Based on the relevant data obtained in step S1, establish the deep detection resistivity R d , shallow detection resistivity R s The relationship between the fluid apparent resistivity R 流 ; S3: Fluid apparent resistivity R obtained in step S2 流 Perform fluid identification.

2. The method for inversely determining apparent resistivity of marine shale gas reservoir fluid according to claim 1, characterized in that: In step S2, the surrounding rock resistivity R of a single well is obtained. 围 , drilling fluid resistivity R 钻 , deep detection resistivity of reservoir section R d , shallow detection resistivity R s The fluid apparent resistivity R is obtained by satisfying the following relations (1) and (2): 流 : In the formula, R d ——deep detection resistivity, Ω.m; R s ——shallow detection resistivity, Ω.m; R 围 ——Resistivity of surrounding rock, Ω.m; R 钻 ——Drilling fluid resistivity, Ω.m; R 流 ——Fluid apparent resistivity, Ω.m.

3. The method for inversely determining apparent resistivity of marine shale gas reservoir fluid according to claim 2, characterized in that: In step S2, the fluid apparent resistivity R 流 The following relationship (3) is satisfied. Considering that under the condition of oil-based mud, R s , R d The value is affected by many factors. The denominator in formula (3) takes the absolute value:

4. The method for inversely determining apparent resistivity of marine shale gas reservoir fluid according to claim 1, characterized in that: In step S3, the fluid apparent resistivity R 流 When the resistivity of the fluid exceeds the maximum resistivity of the water layer in the regional oil test, the well is judged to be gas producing; when the fluid apparent resistivity R 流 When the resistance is lower than the maximum resistance of the test water layer, the well is considered to produce water.

5. The method for inversely determining apparent resistivity of marine shale gas reservoir fluid according to claim 1, characterized in that: In step S3, because the distribution of marine shale in the same reservoir section in the same area is stable and the resistivity has no obvious change, they have been offset in the calculation, and there is no need to obtain the surrounding rock resistivity R 围 The actual measured value.

6. The method for inversely determining apparent resistivity of marine shale gas reservoir fluid according to claim 1, characterized in that: In step S1, the deep detection depth resistivity curve and the shallow detection depth resistivity curve are obtained by measuring with an induction logging instrument.

7. An application of the method for inversely estimating apparent resistivity of marine shale gas reservoir fluid as claimed in claim 1, characterized in that: Used to identify fluid properties in low-resistance wells with apparent resistivity lower than 20Ω.m during drilling and logging.

8. A device for inversely judging the apparent resistivity of marine shale gas reservoir fluid, characterized in that: The device is used to implement the method for back-calculating and distinguishing the apparent resistivity of marine shale gas reservoir fluids as described in any one of claims 1 to 7, and the device comprises: a data acquisition module, a data analysis module and a distinguishing and evaluating module. The data acquisition module is used to obtain the deep and shallow detection depth resistivity curves of a single well; The data analysis module is used to select the deep detection curve and the shallow detection curve, and establish the deep detection resistivity R d , shallow detection resistivity R s The relationship between the fluid apparent resistivity R 流 ; The discrimination and evaluation module is used to calculate the apparent resistivity R of the fluid in a single well. 流 Compare it with the preset value and then determine whether the well is a gas producing well or a water producing well.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable in the processor, characterized in that: When the processor executes the computer program, the method steps described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed in a computer processor, the method according to any one of claims 1 to 7 is implemented.

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