Formation fluid interpretation method and device based on core chloro salt content, equipment and storage medium

Abstract

The application discloses a stratum fluid interpretation method and device based on core chlorosalt content, equipment and a storage medium, relates to the field of drilling geology evaluation technology, and collects logging, well logging data and oil testing data of the tested well in the research area, selects water analysis data corresponding to the gas logging display in the test section, further selects the test section of the selected test section, and obtains the relationship among the core test chlorosalt content, the stratum matrix salt concentration and the stratum water salt concentration through the reservoir rock model, fits the stratum matrix salt concentration and the stratum water salt concentration of the research area, establishes a water and gas layer discrimination function, and is used for judging the properties of other reservoirs in the research area, and solves the problems of difficult drilling reservoir fluid evaluation and low evaluation accuracy in the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of while-drilling geological evaluation, and particularly relates to a formation fluid interpretation method and device based on core chloro-salt content, equipment and a storage medium. BACKGROUND

[0002] At present, there are many researches on reservoir fluid interpretation methods in China, mainly including chart method, curve method, nuclear magnetic resonance, atlas method, etc. The chart method mainly establishes a chart for gas logging parameters and water saturation. The curve method uses outlet temperature, conductivity, density and other drilling fluid logging parameters to determine fluid properties. Light hydrocarbon, geochemistry and quantitative fluorescence can indirectly determine the water content of the reservoir. There is no scheme for establishing a mathematical model for reservoir fluid interpretation using core chloro-salt test content in the prior art.

[0003] While-drilling reservoir fluid evaluation mainly uses gas logging and drilling time as the main basis, which has a certain response to the reservoir. In combination with the influence of engineering parameters such as drilling pressure, rotating speed and displacement on these response parameters, the fluid is interpreted according to the curve shape change or the reservoir fluid evaluation technology based on these parameters. However, due to the characteristics of difficult reservoir division and complex reservoir parameter calculation, while-drilling fluid interpretation faces many difficulties, and often relies on research experience and adjacent well data in actual production.

[0004] In recent years, the core chloro-salt fluid interpretation method is often used in single-well tracking work. Compared with the traditional fluid interpretation method, this method is more suitable for the needs of actual production. However, the current single-well tracking evaluation mainly depends on the matching of the big data statistics of the structure in the research area and the oil test conclusion, and the fluid interpretation standard is established according to the production experience, that is, the quantitative baseline of more than 600 mg / kg for water-based mud and the quantitative baseline of more than 700 mg / kg for oil-based mud are used as the gas-water layer discrimination standard. The disadvantage of this method is that the critical value has uncertainty, and it seriously depends on the single chloro-salt content test result and the experience of single-well tracking personnel, and often cannot accurately reflect the real situation of the formation. For example, in the technical solution of the application number CN201410082190.6, filed by China Petroleum and Natural Gas Group Co., Ltd. and others in 2014, the name of which is "Method for discriminating reservoir fluid type by using while-drilling drilling fluid logging data", drilling fluid parameters are used to interpret reservoir fluid. Since drilling fluid parameters are greatly affected by engineering factors, the method does not work well in actual application.

[0005] Therefore, it is very important to innovate and research new methods on the basis of the chloro-salt content fluid interpretation method. SUMMARY

[0006] The present application aims to provide a formation fluid interpretation method based on core chloride content, and solves the problems of difficult reservoir fluid evaluation while drilling and low evaluation accuracy in the prior art.

[0007] In the present application, a reservoir chloride content equation is established by calculating the pore space chloride content and the reservoir rock matrix chloride content. Based on the core chloride test data, the formation water chloride concentration and the reservoir matrix chloride concentration are fitted through a mathematical model, and then a reservoir gas-water discrimination method is established through the model.

[0008] The technical scheme is specifically as follows:

[0009] The formation fluid interpretation method based on core chloride content comprises the following steps:

[0010] S1, collecting logging, well logging data and oil testing data of the tested wells in the study area, and screening out water analysis data corresponding to the gas logging display in the test section;

[0011] S2, further screening out the chloride ion test well section data from the test section screened out in step S1, and dividing the test section into water layer and gas layer according to the oil testing results;

[0012] S3, obtaining the relationship between the core test chloride content and the formation matrix salt concentration and the formation water salt concentration through a reservoir rock model;

[0013] S4, according to step S3, fitting the formation matrix salt concentration and the formation water salt concentration in the study area by using the core test chloride content big data in the study area;

[0014] S5, obtaining the chloride ion content test data by dividing the water layer and the gas layer according to the oil testing results, establishing a water and gas layer discrimination function, and then using the function to judge the properties of other reservoirs in the study area.

[0015] Further, in step S3, according to the reservoir characteristics, the relationship between the core test chloride content and the formation matrix salt concentration and the formation water salt concentration satisfies the following formula (I),

[0016]

[0017] Wherein, C is the core test chloride content, unit: mg / kg;

[0018] C1 is the formation matrix salt concentration, unit: mg / kg;

[0019] C2 is the formation water salt concentration, unit: mg / kg;

[0020] is the formation porosity;

[0021] V is the volume of the core sample, cm 3 .

[0022] Further, in step S4, according to formula (I), it is derived that the relationship between the core test chlorinated salt content and the formation matrix salt concentration and the formation water salt concentration satisfies the following formula (II),

[0023]

[0024] Further, in step S4, the core test chlorinated salt content big data of the known wells in the study area are used to fit C1 and C2, and according to the water layer and gas layer divided in step S2, C 21 , C 22 two demarcation point values, C 21 <C 22 , and the formation water salt concentration of the reservoir to be evaluated is denoted as C2':

[0025] When C2'≥C 22 , it is a gas layer;

[0026] When C2'≤C 21 , it is a water layer;

[0027] When C 21 <C2' < C 22 , it is a gas-water layer.

[0028] Further, in step S4, according to the characteristics that the matrix chlorinated salt is difficult to change during the formation deposition process, and the chlorinated salt of the void space fluid is greatly increased due to the inflow of the formation water, the two values of C 21 , C 22 in C2 are determined as the demarcation point values of the gas, water and gas-water layers.

[0029] Further, in step S4, when the study area is a carbonate rock deposition reservoir, C 22 is 170, and C 21 is 27.

[0030] A device for determining the formation fluid based on the core chlorinated salt content, which is used to implement the above-mentioned method for interpreting the formation fluid based on the core chlorinated salt content, and comprises a data acquisition module, a data analysis module and a determination and evaluation module.

[0031] The data acquisition module is used to acquire the logging, well logging data and oil testing data of the tested oil wells in the study area, and acquire the core test chlorinated salt content big data of the study area.

[0032] The data analysis module is used for screening out the gas logging display corresponding water analysis data in the test section, and dividing the water layer and the gas layer according to the oil test result, fitting the formation matrix salt concentration and the formation water salt concentration in the research area, establishing the water and gas layer discrimination function, and obtaining the relationship between the core test chlorinated salt content and the formation matrix salt concentration and the formation water salt concentration.

[0033] The discrimination evaluation module is used for evaluating the reservoir property of the well to be tested in the research area according to the relationship between the core test chlorinated salt content and the formation matrix salt concentration and the formation water salt concentration of the well tested in the research area.

[0034] A computer device comprises a memory, a processor and a computer program stored in the memory and executable in the processor, and the processor implements the above method steps when executing the computer program.

[0035] A computer readable storage medium stores a computer program, and the computer program is executable in a computer processor to implement the above method.

[0036] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0037] Firstly, the present application innovatively proposes a mathematical model for interpreting reservoir fluid by using core chlorinated salt test content. The drilling fluid parameters used for fluid interpretation before are often disturbed by various engineering factors, so that the curve method for fluid interpretation cannot accurately reflect the true situation of the formation fluid property. The core chlorinated salt content is the most direct reaction of the formation fluid on the core, so the present application establishes a formation fluid interpretation model based on the core chlorinated salt content, which greatly improves the accuracy of fluid interpretation. In actual tracking work, the establishment of fluid interpretation standard can divide the water layer and the gas layer to a certain extent according to the production experience. However, due to the heterogeneity of the research area, the uncertainty of experience and other reasons, the standard has errors, so the present application establishes a discrimination function through mathematical model derivation, quantitatively distinguishes the gas layer and the water layer by the chlorinated salt content, and greatly improves the efficiency of fluid interpretation.

[0038] Secondly, the present application innovatively proposes to calculate the pore space chlorinated salt content and the reservoir rock matrix chlorinated salt content by using the core chlorinated salt test content.

[0039] During the formation deposition process, with the compaction of overlying formation, the chloride salt content in the formation water entering the compacted formation matrix is stable at 100-200 mg / kg, and with the dissolution occurring in the late formation deposition process, the formation water enters the pore space, greatly increasing the chloride salt content of the formation, and the greater the dissolution intensity, the greater the chloride salt content. Therefore, simply considering the chloride salt content to explain the formation fluid ignores the influence of porosity. The present application establishes a reservoir chloride salt content equation through a reservoir rock model, fully considers the influence of the pore space on the chloride salt, and calculates the pore space chloride salt content and the reservoir rock matrix chloride salt content by using the core chloride salt test content, so that the reservoir fluid interpretation model can better reflect the real fluid properties of the formation. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is the logging interpretation profile of well A in Example 1.

[0041] Figure 2 is the gas-water discrimination chart obtained by simulation in Example 1. DETAILED DESCRIPTION

[0042] The present application will be further described in detail below in combination with examples, but the embodiments of the present application are not limited thereto.

[0043] Example 1

[0044] In order to facilitate the public to understand the present scheme, the present example takes the tested oil well in a certain research area as an example to further illustrate the formation fluid interpretation method based on the core chloride salt content in the present application, which belongs to the technical field of drilling geology evaluation.

[0045] Specifically includes the following steps:

[0046] Step one: collect the logging, well logging data and oil testing data of the tested oil well in the research area, and screen out the water analysis data corresponding to the gas logging display in the test section.

[0047] Step two: further screen out the chloride ion test well section data in the test section screened out in step one, and divide the test section into water layer and gas layer according to the oil testing results.

[0048] Reference Figure 1 , Figure 1 is the logging interpretation profile of well A in the research area.

[0049] Step three: obtain the relationship between the core test chloride salt content and the formation matrix salt concentration and the formation water salt concentration through the reservoir rock model.

[0050] In the present example, the relationship between the core test chloride salt content and the formation matrix salt concentration and the formation water salt concentration satisfies the following formula (I),

[0051]

[0052] Wherein, C is the core test chloride salt content, unit mg / kg;

[0053] C1 is the formation matrix salt concentration, unit mg / kg;

[0054] C2 is the formation water salt concentration, unit mg / kg;

[0055] Porosity of the formation;

[0056] V is the core sample volume, cm 3 .

[0057] Step four: according to step S3, using the core test chloride salt content of the study area big data, fitting the study area to get the formation matrix salt concentration, formation water salt concentration.

[0058] In this step, according to formula (I) deduced, the relationship between core test chloride salt content and formation matrix salt concentration, formation water salt concentration satisfies the following formula (II),

[0059]

[0060] In this embodiment, because the matrix chloride salt content is basically unchanged during the deposition process, with the formation water flowing into the pore space, the chloride salt content of water layer and gas layer is different, the chloride salt content of water layer is obviously higher than that of gas layer, through the analysis of oil test data of the study area, reference to the attached Figure 1 , the core data of the study area is fitted to get C1, C2.

[0061] According to step two, combined with the water layer and gas layer divided by oil test results, according to the attached Figure 1 , the relationship formula (III), (IV) is fitted respectively,

[0062] y=178.51x+118 (III) ;

[0063] y=27.19x+120 (IV).

[0064] Step five: through the oil test results, the water layer and gas layer are divided respectively to get the chloride ion content test data, using the formation matrix salt concentration, formation water salt concentration obtained by the above step one-step three, the water and gas layer discrimination function is established, and the nature of the reservoir is judged.

[0065] In this embodiment, combined with the analysis results of the oil testing data of the research area and the relations (III) and (IV) calculated in step four, combined with the actual production situation and the geological understanding of the research area, the discrimination accuracy and reliability of the gas layer and the water layer are improved as much as possible, the gas line and the water line standards are set to 170 and 27 in this embodiment, and the specific discrimination method is as follows:

[0066] that is, when C2 is greater than or equal to 170, it is a gas layer;

[0067] when C2 is less than 27, it is a water layer;

[0068] when 27 < C2 < 170, it is a gas-water layer.

[0069] Then, according to the gas-water discrimination equation, the D layer of well A in the P well area is evaluated, and the results are shown in Table 1. As shown in Table 1, the mud logging interpretation results obtained by using the present scheme are consistent with the oil testing results.

[0070] Table 1: Comparison table of mud logging interpretation results and oil testing results

[0071]

[0072] As shown in Table 1, the mud logging interpretation results obtained by using the present method are consistent with the oil testing results of the well sections with well numbers 1-4.

[0073] The inventor of the present scheme has obtained, through many experiments, that the evaluation results of the reservoir obtained by using the present scheme are compared with the oil testing results, and the coincidence rate can reach 85%, which is obviously higher than the results obtained by using the conventional chart method, curve method, nuclear magnetic resonance and spectrum method.

[0074] Furthermore, the present application also provides a formation fluid discrimination device based on core chlorides content, which is used to realize the above-mentioned formation fluid interpretation method based on core chlorides content, and comprises a data acquisition module, a data analysis module and a discrimination and evaluation module.

[0075] The data acquisition module is used to acquire the mud logging and logging data and oil testing data of the oil tested wells in the research area, and acquire the core test chlorides content big data of the research area.

[0076] The data analysis module is used to screen out the water analysis data corresponding to the gas measurement display in the test section, and divide them into water layers and gas layers according to the oil testing results, fit the formation matrix salt concentration and the formation water salt concentration of the research area, establish a water and gas layer discrimination function, and obtain the relationship between the core test chlorides content and the formation matrix salt concentration and the formation water salt concentration.

[0077] The discriminant evaluation module is used for evaluating the reservoir property of the well to be tested in the research area according to the relationship between the core test chlorinated salt content of the tested well in the research area and the salt concentration of the formation matrix and the salt concentration of the formation water, and quickly determining whether the well to be tested is a gas layer, a water layer or a gas-water layer.

[0078] Further, the present application also provides a computer device, which comprises a memory, a processor and a computer program stored in the memory and executable in the processor, and the processor implements the above method steps when executing the computer program.

[0079] Further, the present application also provides a computer readable storage medium, which stores a computer program, and the computer program is executable in a computer processor to implement the above method.

[0080] The above is only the preferred embodiment of the present application, and does not limit the present application in any form, and any simple modification and equivalent change of the above embodiment according to the technical essence of the present application all fall within the protection scope of the present application.

Claims

1. A method for formation fluid interpretation based on core chlorinity content, characterized in that, It comprises the following steps: S1, collecting the well logging, logging data and test data of the tested well in the study area, and screening out the water analysis data corresponding to the gas logging display in the test section; S2, further screening out the chloride ion test well section data from the test section screened out in step S1, and dividing it into water layer and gas layer according to the test results; S3, further obtaining the relationship between the core test chloride salt content and the formation matrix salt concentration and the formation water salt concentration through the reservoir rock model; S4, according to step S3, using the core test chloride salt content big data of the study area to fit the formation matrix salt concentration and the formation water salt concentration of the study area; S5, through the test results of water layer and gas layer, the chloride ion content test data is obtained, the water and gas layer discrimination function is established, and then it is used to judge the properties of other reservoirs in the study area.

2. The method for formation fluid interpretation based on core chlorinity content of claim 1, wherein: In step S3, according to the characteristics of the reservoir, the relationship between the core test chloride salt content and the formation matrix salt concentration and the formation water salt concentration satisfies the following formula (I), C = V x φ x C1 + V x (1-φ) x C2 (I), Wherein, C is the core test chloride salt content, unit: mg / kg; C1 is the formation matrix salt concentration, unit: mg / kg; C2 is the formation water salt concentration, unit: mg / kg; φ is the formation porosity; V is the volume of the core sample, cm 3 .

3. The method for formation fluid interpretation based on core chlorinity content of claim 2, wherein: In step S4, according to formula (I), the relationship between the core test chloride salt content and the formation matrix salt concentration and the formation water salt concentration satisfies the following formula (II), C / V = C1 + (1-φ) / φ x C2 (II).

4. The method for formation fluid interpretation based on core chlorinity content of claim 3, wherein: In step S4, C1 and C2 are obtained by using the core test chloro salt content big data of the known wells in the research area for fitting, and C 21 , C 22 two demarcation point values, C 21 <C 22 , and the salt concentration of the formation water of the reservoir to be evaluated is denoted as C2': when C2'≥C 22 , it is a gas layer; When C2' < C 21 then it is a water layer; When C 21 <C2' < C 22 then the gas and water are in the same layer.

5. The method for formation fluid interpretation based on core chlorinity content of claim 4, wherein: In step S4, the two values in C2 are determined as the gas, water and gas-water contact values based on the fact that the matrix chlorinated salt is difficult to change during the formation deposition process, and the fluid in the void space is substantially increased due to the inflow of the formation water. 21 , 22 two values as the gas, water and gas-water contact values.

6. The method for formation fluid interpretation based on core chlorinity content of claim 5, wherein: When the area to be studied is a carbonate rock sedimentary reservoir, C 22 is 170, C 21 is 27.

7. A device for discriminating formation fluids based on core chlorinity content, comprising: The device is used to realize the formation fluid interpretation method based on core chloride salt content in the above claims 1-6, which comprises a data acquisition module, a data analysis module and a discrimination evaluation module; The data acquisition module is used to acquire the well logging, logging data and test data of the tested well in the study area, and acquire the core test chloride salt content big data of the study area; The data analysis module is used to screen out the water analysis data corresponding to the gas logging display in the test section, and divide it into water layer and gas layer according to the test results, fit the formation matrix salt concentration and the formation water salt concentration of the study area, establish the water and gas layer discrimination function, and obtain the relationship between the core test chloride salt content and the formation matrix salt concentration and the formation water salt concentration; The discrimination evaluation module is used to evaluate the reservoir properties of the well to be tested in the study area according to the relationship between the core test chloride salt content and the formation matrix salt concentration and the formation water salt concentration of the tested well in the study area.

8. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable in the processor, characterized in that, The processor executes the computer program to realize the method steps of any one of the above claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, which is executed in the computer processor to realize the method of any one of the above claims 1-6.

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