Optimal selection method and device for favorable area of multi-thin-layer tight gas reservoir and electronic equipment

Abstract

The invention discloses an optimal selection method and device for a favorable area of a multi-thin-layer tight gas reservoir and electronic equipment. The optimal selection method comprises the following steps: calculating an interlayer difference coefficient of each gas-bearing layer according to the pressure and permeability of each gas-bearing layer; calculating the single-layer open-flow capacity of each gas-bearing layer according to the porosity, the gas saturation, the permeability and the gas-bearing layer thickness of each gas-bearing layer; multiplying the interlayer difference coefficient of each gas-bearing layer by the single-layer open-flow capacity, and accumulating results to obtain single-well combined-layer open-flow capacity; classifying the single wells according to the single well combined layer open flow capacity, and predicting the favorable area of the multi-thin-layer tight gas reservoir according to the classification result in combination with the sand body distribution characteristics. According to the optimal selection method for the favorable area of the multi-thin-layer tight gas reservoir, interlayer difference and interference characteristics are fully considered, the pressure and the permeability are adopted as parameters, the quantitative optimal selection method for the favorable area of the multi-thin-layer laminated tight gas reservoir is provided, development benefits can be improved, and the yield can be kept stable.

Description

Technical Field

[0001] The invention belongs to the technical field of natural gas development, and in particular relates to a method, a device and an electronic device for optimizing favorable areas of multi-thin-layer tight gas reservoirs. Background Art

[0002] In multi-thin-layer tight gas reservoirs, the thickness of a single layer is thin, and there are large differences between and within layers. It is difficult to accurately select favorable areas for multi-layer superposition and optimize the development method, which affects the efficient and fine development of the gas field.

[0003] The optimization of favorable target areas affects the efficient and fine development of gas fields. At present, the relevant background technologies are roughly divided into two categories: one is a qualitative prediction method of favorable areas based on geological, seismic and other data combined with geological knowledge; the other is a quantitative prediction method of favorable areas based on the reference of reserve abundance value by standardizing the gas production capacity of different strata, and then obtaining the total corrected reserve abundance of the vertical strata of the gas well. These methods do not fully consider the impact of inter-layer differences on the optimization of favorable areas of multi-thin layer superimposed gas reservoirs. The optimization method of favorable areas of multi-layer gas reservoirs in the study area has successively experienced the first generation of comprehensive index method based on gas production profile testing and the second generation of reservoir coefficient capacity splitting method, which met the needs of production construction at that time, but all have limitations.

[0004] The patent application number is CN111608649A, and the name is the prediction method of favorable areas for shale gas exploration with exogenous replenishment. It discloses a method for predicting natural shale gas flow in low-exploration areas, identifying and predicting regional natural fractures in organic-rich mud shale, obtaining the stress sensitivity function of fracture permeability in mud shale by fitting to reduce errors, and introducing the virtual well single well production capacity prediction technology into favorable area assessment to reduce investment risks. The method can identify the structure of natural regional slip faults in mud shale, quantitatively calculate the displacement of slip faults, and predict the spatial distribution characteristics of fracture belts. Although the patent can obtain the permeability sensitivity function of fractures in mud shale by fitting, and realize the quantitative prediction of the spatial variation law of permeability, the method of the patent application is only applicable to the prediction of shale gas with low exploration degree, not applicable to multi-thin layer tight gas reservoirs, and does not fully consider the difference between layers. Summary of the invention

[0005] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a method, device and electronic equipment for optimizing favorable areas of multi-thin-layer tight gas reservoirs, which can calculate the unobstructed flow rate of a single well by calculating different gas-containing layers, and then optimize the favorable areas of multi-thin-layer superimposed gas reservoirs based on the calculation results.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for selecting favorable areas of multi-thin-layer tight gas reservoirs comprises the following steps:

[0008] S1: Pressure P through each gas-bearing layer i and permeability K i Calculate the interlayer difference coefficient D of each gas-bearing layer i ;

[0009] S2: Porosity through each gas-bearing layer Gas saturation Sg i , permeability K i and the thickness of the gas-bearing layer H i Calculate the single-layer unimpeded flow rate Q of each gas-bearing layer AOFi ;

[0010] S3: The interlayer difference coefficient D of each gas-bearing layer i The single layer unimpeded flow Q AOFi Multiply and add the results to get the single well combined layer unobstructed flow Q 单井 ;

[0011] S4: Based on the single well combined layer unobstructed flow Q 单井 The single wells are classified, and the favorable areas of multi-thin-layer tight gas reservoirs are predicted based on the classification results and the sand body distribution characteristics.

[0012] Optionally, in step S1, the interlayer difference coefficient D of each gas-bearing layer i The calculation formula is as follows:

[0013]

[0014] Among them, D i is the inter-layer difference coefficient of each gas-bearing layer, dimensionless;

[0015] P i is the pressure of each gas-bearing layer, in MPa;

[0016] K i is the permeability of each gas-bearing layer, in units of 10 -3 μm 2 .

[0017] Optionally, in step S2, the single layer unimpeded flow rate Q of the gas-containing layer AOFi The calculation formula is as follows:

[0018]

[0019] Among them, Q AOFi is the single-layer unimpeded flow rate of each gas-bearing layer, in 10,000 m 3 / d;

[0020] Φ iis the porosity of each gas-bearing layer, in %;

[0021] S i is the gas saturation of each gas-bearing layer, in %;

[0022] H i is the thickness of each gas-bearing layer, in ten thousand m;

[0023] a and b are relationship coefficients.

[0024] Optionally, in step S3, the calculation formula is as follows:

[0025]

[0026] Among them, Q 单井 is the single well combined layer unimpeded flow rate, in ten thousand m 3 / d;

[0027] α is the relationship coefficient, dimensionless;

[0028] D i is the inter-layer difference coefficient of each gas-bearing layer, dimensionless;

[0029] Q AOFi is the single-layer unimpeded flow rate of each gas-bearing layer, in 10,000 m 3 / d.

[0030] Optionally, in step S4, the classification method of a single well is as follows:

[0031] If the single well combined layer has no obstruction flow Q 单井 More than 10,000 m 3 , and less than 40,000 m 3 , then the single well is a third-category single well;

[0032] If the single well combined layer has no obstruction flow Q 单井 More than 40,000 m 3 , and less than 100,000 m 3 , then the single well is a second-type single well;

[0033] If the single well combined layer has no obstruction flow Q 单井 More than 100,000 m 3 , then the single well is a first-class single well.

[0034] Optionally, before step S1, pressure data, permeability data, porosity data, gas saturation data and gas layer permeability data of each gas-bearing layer need to be collected.

[0035] Optionally, before step S1, thickness data of each gas-bearing layer needs to be collected.

[0036] A device for optimizing favorable areas of multi-thin-layer tight gas reservoirs, comprising:

[0037] The inter-layer difference coefficient calculation module is used to calculate the pressure P of each gas-bearing layer. i and permeability K i Calculate the interlayer difference coefficient D of each gas-bearing layer i ;

[0038] Single-layer unobstructed flow calculation module, used to calculate the porosity of each gas-bearing layer Gas saturation Sg i , gas-bearing layer permeability K i and the thickness of the gas-bearing layer H i Calculate the single-layer unimpeded flow rate Q of each gas-bearing layer AOFi ;

[0039] The single well combined layer unobstructed flow calculation module is used to calculate the interlayer difference coefficient D of each gas-bearing layer. i The single layer unimpeded flow Q AOFi Multiply and add the results to get the single well combined layer unobstructed flow Q 单井 ;

[0040] The classification prediction module is used to predict the unobstructed flow rate Q of a single well and layer. 单井 The single wells are classified, and the favorable areas of multi-thin-layer tight gas reservoirs are predicted based on the classification results and the sand body distribution characteristics.

[0041] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of a method for selecting a favorable area of ​​a multi-thin-layer tight gas reservoir when executing the computer program.

[0042] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for selecting a favorable area of ​​a multi-thin-layer tight gas reservoir.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The method for selecting favorable areas of multi-thin-layer tight gas reservoirs of the present invention fully considers the inter-layer differences and interference characteristics, adopts pressure and permeability as parameters, and proposes a quantitative selection method for favorable areas specifically for multi-thin-layer superimposed tight gas reservoirs, which can improve development benefits and maintain stable production. The present invention is based on the previous method for selecting favorable areas of multi-thin-layer superimposed tight gas reservoirs. It is an improved method that fully considers the core factor of inter-layer differences, and can more accurately and efficiently predict the gas well productivity, and then select favorable areas.

[0045] Furthermore, the present invention constructs an interlayer difference coefficient to predict gas well productivity using the core factors of interlayer difference (pressure, permeability) as parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

[0047] Figure 1 It is a calculation step diagram of the present invention;

[0048] Figure 2 It is a schematic diagram of the modules of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0051] It should be noted that in the claims, any reference signs placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The present application may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0052] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0053] The present invention is described in detail below with reference to the accompanying drawings.

[0054] like Figure 1 As shown, a method for optimizing favorable areas of multi-thin-layer tight gas reservoirs of the present invention comprises the following steps:

[0055] First, it is necessary to collect the pressure data of each gas-bearing layer and the permeability data, porosity data, gas saturation data and thickness data of each gas-bearing layer.

[0056] The pressure P of each gas-bearing layer i and permeability K i Calculate the interlayer difference coefficient D of each gas-bearing layer i ;

[0057] The porosity of each gas-bearing layer Gas saturation Sg i , permeability K i and the thickness of the gas-bearing layer H i Calculate the single-layer unimpeded flow rate Q of each gas-bearing layer AOFi ;

[0058] The inter-layer difference coefficient D of each gas-bearing layer i The single layer unimpeded flow Q AOFi Multiply and add the results to get the single well combined layer unobstructed flow Q 单井 ;

[0059] Finally, according to the single well combined layer unimpeded flow Q 单井 The single wells are classified, and the favorable areas of multi-thin-layer tight gas reservoirs are predicted based on the classification results and the sand body distribution characteristics.

[0060] Based on the above calculation results, according to the single well combined layer open flow Q 单井 The classification method of single wells is as follows:

[0061] If the single well combined layer has no obstruction flow Q 单井 More than 10,000 m 3 , and less than 40,000 m 3 , then the single well is a Class III single well;

[0062] If the single well combined layer has no obstruction flow Q 单井 More than 40,000 m 3 , and less than 100,000 m 3 , then the single well is a Class II single well;

[0063] If the single well combined layer has no obstruction flow Q 单井 More than 100,000 m 3 , then the single well is a Class I single well.

[0064] Finally, the favorable superposition areas are predicted based on the sand bodies and effective sand body distribution characteristics of each gas-bearing stratum characterized by actual drilling data.

[0065] See also Figure 2 , a device for optimizing favorable areas of multi-thin-layer tight gas reservoirs, comprising:

[0066] The first processing module is used to pass the pressure P of each gas-bearing layer. i and permeability K i Calculate the interlayer difference coefficient D of each gas-bearing layer i ;

[0067] The second processing module is used to analyze the porosity of each gas-bearing layer. Gas saturation Sg i , gas-bearing layer permeability K i and the thickness of the gas-bearing layer H i Calculate the single-layer unimpeded flow rate Q of each gas-bearing layer AOFi ;

[0068] The third processing module is used to convert the inter-layer difference coefficient D of each gas-bearing layer into i The single layer unimpeded flow Q AOFi Multiply and add the results to get the single well combined layer unobstructed flow Q 单井 ;

[0069] The fourth processing module is used to calculate the single well combined layer unobstructed flow Q 单井 The single wells are classified, and the favorable areas of multi-thin-layer tight gas reservoirs are predicted based on the classification results and the sand body distribution characteristics.

[0070] Example 1

[0071] In this embodiment, the interlayer difference coefficient D of each gas-bearing layer is calculated by the following formula: i :

[0072]

[0073] Among them, D i is the inter-layer difference coefficient of each gas-bearing layer, dimensionless;

[0074] P i is the pressure of each gas-bearing layer, in MPa;

[0075] K i is the permeability of each gas-bearing layer, in units of 10 -3 μm 2 ;

[0076] The single-layer unimpeded flow rate Q of each gas-bearing layer is calculated by the following formula AOFi :

[0077] Depend on

[0078] have to:

[0079]

[0080] Among them, Q AOFi is the single-layer unimpeded flow rate of each gas-bearing layer, in 10,000 m 3 / d;

[0081] Φ i is the porosity of each gas-bearing layer, in %;

[0082] S i is the gas saturation of each gas-bearing layer, in %;

[0083] H i is the thickness of each gas-bearing layer, in ten thousand m;

[0084] a and b are relationship coefficients. a and b are constants obtained by regression between the single-layer unimpeded flow rate obtained by gas testing and the single-layer comprehensive production capacity factor Pi for each gas-bearing layer.

[0085] The single well combined layer unimpeded flow Q is calculated by the following formula 单井 :

[0086]

[0087] Among them, Q 单井 is the single well combined layer unimpeded flow rate, in ten thousand m 3 / d;

[0088] α is the relationship coefficient;

[0089] D i is the inter-layer difference coefficient of each gas-bearing layer, dimensionless;

[0090] Q AOFi is the single-layer unimpeded flow rate of each gas-bearing layer, in 10,000 m 3 / d.

[0091] Example 2

[0092] The method of the present invention is used to calculate the single well open flow rate of the double 28-70C8 well. The parameters of this example are shown in Table 1, and the main steps include:

[0093] Table 1

[0094]

[0095] Step 1: Calculate the interlayer difference coefficient of the two gas-bearing strata on Box 8 and Mountain 11:

[0096] D 盒8 =0.176D山1 =0.824

[0097] Step 2: Calculate the single layer unobstructedness of the two gas-bearing strata on box 8 and mountain 11:

[0098] Q 盒8 =2.744×10 4 m 3 / d Q 山1 =15.92×10 4 m 3 / d

[0099] Step 3: Calculate the open-flow capacity of a single well and layer, with the relationship coefficient α = 0.6277:

[0100] Q 合 =0.6277(D 盒8 Q 盒8 +D 山1 Q 山1 )=8.54×10 4 m 3 / d, which is equal to the actual unimpeded flow rate of 9.26×10 4 m 3 / dThe error is small and the prediction effect is better.

[0101] Step 4: Based on the static indicators, the Shuang 28-70C8 well is classified as the first type of well.

[0102] Step 5: Predict the favorable superposition area based on the sand body distribution characteristics.

[0103] It should be understood by those skilled in the art that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0104] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0105] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0106] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0107] Unless otherwise specified, the working modes or control modes involved in the above embodiments are all conventional working modes or control modes in the art.

[0108] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in the field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for selecting favorable areas of multi-thin-layer tight gas reservoirs, characterized in that: The following steps are involved: S1: Pressure P through each gas-bearing layer i and permeability K i Calculate the interlayer difference coefficient D of each gas-bearing layer i ; S2: Porosity through each gas-bearing layer Gas saturation Sg i , permeability K i and the thickness of the gas-bearing layer H i Calculate the single-layer unimpeded flow rate Q of each gas-bearing layer AOFi ; S3: The inter-layer difference coefficient D of each gas-bearing layer i The single layer unimpeded flow rate Q AOFi Multiply and add the results to get the single well combined layer unobstructed flow Q 单井 ; S4: Based on the single well combined layer unobstructed flow Q 单井 The single wells are classified, and the favorable areas of multi-thin-layer tight gas reservoirs are predicted based on the classification results and the sand body distribution characteristics.

2. A method for selecting favorable areas of multi-thin-layer tight gas reservoirs according to claim 1, characterized in that: In step S1, the interlayer difference coefficient D of each gas-bearing layer i The calculation formula is as follows: Among them, D i is the inter-layer difference coefficient of each gas-bearing layer, dimensionless; P i is the pressure of each gas-bearing layer, in MPa; K i is the permeability of each gas-bearing layer, in units of 10 -3 μm 2 .

3. The method for selecting favorable areas of multi-thin-layer tight gas reservoirs according to claim 1, characterized in that: In step S2, the single layer unimpeded flow rate Q of the gas-containing layer AOFi The calculation formula is as follows: Among them, Q AOFi is the single-layer unimpeded flow rate of each gas-bearing layer, in 10,000 m 3 / d; Φ i is the porosity of each gas-bearing layer, in %; S i is the gas saturation of each gas-bearing layer, in %; H i is the thickness of each gas-bearing layer, in ten thousand m; a and b are relationship coefficients.

4. A method for selecting favorable areas of multi-thin-layer tight gas reservoirs according to claim 1, characterized in that: In step S3, the calculation formula is as follows: Among them, Q 单井 is the single well combined layer unimpeded flow rate, in ten thousand m 3 / d; α is the relationship coefficient, dimensionless; D i is the inter-layer difference coefficient of each gas-bearing layer, dimensionless; Q AOFi is the single-layer unimpeded flow rate of each gas-bearing layer, in 10,000 m 3 / d.

5. The method for selecting favorable areas of multi-thin-layer tight gas reservoirs according to claim 1, characterized in that: In step S4, the classification method of a single well is as follows: If the single well combined layer has no obstruction flow Q 单井 More than 10,000 m 3 , and less than 40,000 m 3 , then the single well is a third-category single well; If the single well combined layer has no obstruction flow Q 单井 More than 40,000 m 3 , and less than 100,000 m 3 , then the single well is a second-type single well; If the single well combined layer has no obstruction flow Q 单井 More than 100,000 m 3 , then the single well is a first-class single well.

6. A method for selecting favorable areas of multi-thin-layer tight gas reservoirs according to claim 1, characterized in that: Before step S1, it is necessary to collect pressure data, permeability data, porosity data, gas saturation data and gas layer permeability data of each gas-bearing layer.

7. The method for selecting favorable areas of multi-thin-layer tight gas reservoirs according to claim 1, characterized in that: Before step S1, thickness data of each gas-bearing layer needs to be collected.

8. A device for optimizing favorable areas of multi-thin-layer tight gas reservoirs, characterized in that: include: The inter-layer difference coefficient calculation module is used to calculate the pressure P of each gas-bearing layer. i and permeability K i Calculate the interlayer difference coefficient D of each gas-bearing layer i ; Single-layer unobstructed flow calculation module, used to calculate the porosity of each gas-bearing layer Gas saturation Sg i , gas-bearing layer permeability K i and the thickness of the gas-bearing layer H i Calculate the single-layer unimpeded flow rate Q of each gas-bearing layer AOFi ; The single well combined layer unobstructed flow calculation module is used to calculate the interlayer difference coefficient D of each gas-bearing layer. i The single layer unimpeded flow rate Q AOFi Multiply and add the results to get the single well combined layer unobstructed flow Q 单井 ; The classification prediction module is used to predict the unobstructed flow rate Q of a single well and layer. 单井 The single wells are classified, and the favorable areas of multi-thin-layer tight gas reservoirs are predicted based on the classification results and the sand body distribution characteristics.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of a method for selecting a favorable area of ​​a multi-thin-layer tight gas reservoir as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of a method for selecting a favorable area of ​​a multi-thin-layer tight gas reservoir as claimed in any one of claims 1 to 7.

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