A shale gas horizontal well reasonable well spacing calculation method, medium and device

Abstract

This invention provides a method, medium, and apparatus for calculating the reasonable well spacing of shale gas horizontal wells. By constructing and calibrating an integrated geological and engineering numerical simulation model of a shale gas development platform, it simulates and calculates the changes in the platform's average well recovery rate (EUR) and recovery rate with well spacing. A single-objective fitting function is optimized, and a multi-objective function is constructed to evaluate the EUR and recovery rate. Finally, the reasonable well spacing of shale gas horizontal wells is calculated. Shale gas reservoirs are "continuous" reservoirs, exhibiting a "one well, one reservoir" characteristic during development. Therefore, well spacing has a significant impact on the production efficiency of a single well on the platform and the full utilization of block resources. The calculation method in this invention selects the two most important factors in current shale gas development as objective functions, providing a more comprehensive demonstration method and more reliable calculation results. The resulting well spacing calculation method is of great significance for ensuring gas well production efficiency and avoiding waste of reserve resources. It can be widely applied in the field of shale / tight gas development and has broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of shale gas reservoir technology, and more specifically, to a method, medium, and apparatus for calculating the reasonable well spacing of shale gas horizontal wells. Background Technology

[0002] Shale gas reservoirs are self-generated and self-storing reservoirs, exhibiting a "one well, one reservoir" characteristic during development. The well spacing of shale gas horizontal wells is a crucial factor affecting the production efficiency and resource utilization of individual wells. Excessive spacing results in a larger controlled area per well, leading to higher recovery rates (EUR) but insufficient utilization of inter-well resources and lower block recovery rates, resulting in resource waste. Conversely, insufficient spacing results in a smaller controlled area per well, leading to full utilization of inter-well resources and higher block recovery rates, but significant overlap of pressure drop zones causes severe inter-well interference, further reducing EUR and impacting single-well productivity and profitability. Therefore, accurately calculating the optimal well spacing for shale gas horizontal wells while ensuring both single-well EUR and block recovery rates is of great significance for shale gas deployment optimization. However, current methods proposed by domestic scholars for calculating optimal well spacing generally only consider indicators such as well controlled area, single-well EUR, and single-well investment cost. In the actual development of shale gas reservoirs, a reasonable well spacing should not only help reduce the impact of inter-well interference on the development effect of a single well, but also ensure the full utilization of inter-well resources, thereby achieving a balance between the recovery rate of a single well and the recovery rate of the platform, and maximizing the development benefits and resource utilization of a single well. Summary of the Invention

[0003] This invention aims to provide a method, medium, and apparatus for calculating the reasonable well spacing of shale gas horizontal wells, in order to solve the problem that current shale gas well spacing optimization methods cannot comprehensively and quantitatively consider the impact of single-well EUR and platform recovery rate.

[0004] This invention provides a method for calculating the reasonable well spacing of shale gas horizontal wells, comprising the following steps:

[0005] S100, combining 3D seismic data, well logging data, microseismic data, drilling parameters and fracturing operation parameters, establishes an integrated numerical simulation model of platform geology and engineering;

[0006] S200 uses the Nelder-Mead simplex method to iteratively update the fitting parameters of the integrated numerical simulation model of platform geology and engineering, thereby correcting the integrated numerical simulation model of platform geology and engineering.

[0007] S300, using the corrected platform geological engineering integrated numerical simulation model, calculate the well-average EUR and recovery rate R at a certain well spacing;

[0008] Based on the corrected platform geological engineering integrated numerical simulation model, S400 platform well group models with different well spacings are constructed, and the average well EUR and recovery rate R under different well spacings are simulated and calculated.

[0009] S500 performs dimensionless processing on well-average EUR and recovery rate R under different well spacings;

[0010] S600, plot the dimensionless values ​​of well-average EUR and recovery rate R as a function of well spacing;

[0011] S700, combining the data variation patterns of the average well EUR and recovery rate R with well spacing, select the functions of average well EUR with well spacing and recovery rate R with well spacing;

[0012] S800, based on the function of average well EUR as a function of well spacing and the function of recovery rate R as a function of well spacing, constructs a dual objective function model of average well EUR-recovery rate R, and uses a multi-objective function optimization analysis method to determine the Pareto optimal solution, and calculates the reasonable well spacing corresponding to the platform well group.

[0013] Furthermore, the method for calculating the well-average EUR and recovery rate R at a certain well spacing in step S300 is as follows:

[0014] EUR ave =(EUR1+EUR) 2+ EUR 3+ …+EUR n ) / n;

[0015] R = (EUR1 + EUR) 2+ EUR 3+ …+EUR n ) / V OGIP ;

[0016] in:

[0017] n represents the number of wells, in units of wells;

[0018] EUR represents the cumulative gas production of a gas well, in units of 10. 8 m 3 ;

[0019] EUR1~EUR n These represent the cumulative gas production of wells from well number 1 to well number n.

[0020] EUR ave The average wellbore volume is expressed in EUR, with units of 10. 8 m 3 ;

[0021] R represents the recovery rate, expressed as a percentage.

[0022] V OGIP This represents the original geological reserves of the model, in units of 10. 8 m 3 .

[0023] Furthermore, the method for dimensionless processing of the well-average EUR and recovery rate R under different well spacings in step S500 is as follows:

[0024] Suppose there are *a* shale gas development platforms to be evaluated, denoted as λ = {λ1, λ2, ..., λ...} a There are b characteristic parameters, denoted as ζ = {ζ1, ζ2, ..., ζ}. b}, x ij (i = 1, 2, ..., a; j = 1, 2, ..., b) represents the platform λ i Regarding the j-th indicator value, the matrix N consisting of a platforms and b indicators is (x ij ) b×a This is the evaluation matrix of the set of solutions to the set of indicators;

[0025] Let λ0 be the relative ideal target shale gas development platform relative to the index X. j The attribute value is λ 0j The following formula is used to initialize the well-average EUR and recovery rate R to achieve dimensionless processing:

[0026]

[0027] in:

[0028] S j This represents the standard deviation of the indicator;

[0029] I1 represents the set of subscripts for standardized indicators (eliminating differences in the degree of variation among indicators, but not suitable for comprehensive evaluation of multiple indicators);

[0030] I2 represents the set of subscripts for normalized indicators (applicable to comprehensive evaluation of multiple indicators).

[0031] To better achieve comprehensive evaluation of multiple indicators, the indicator values ​​are assigned to the I2 set, and the well-average EUR and recovery rate R are dimensionless using a normalization method. Furthermore, the evaluation matrix can organize different evaluation parameters j of different platforms i into a single matrix, making it easier to retrieve parameters for dimensionless processing.

[0032] Furthermore, step S700 includes:

[0033] First, based on the data variation patterns of the well-average EUR and recovery rate R with well spacing, a series of functional relationships are initially selected;

[0034] The data was then fitted using the curve fitting module in MATLAB. The error results of the series of functional relationships were compared, and finally the functions of well-average EUR and well spacing and the recovery rate R and well spacing were selected.

[0035] Furthermore, the series of functional relationships includes three types:

[0036] The first type: f(x) = a ln[b(xc)] - d;

[0037] The second type: f(x) = a + bx + cx 2 ;

[0038] The third type: f(x) = a + sin(bx + c);

[0039] Where a, b, c, and d are all fitting coefficients.

[0040] Furthermore, we selected the functional relationships with smaller sums of squared errors as functions of well-average EUR as a function of well spacing and recovery rate R as a function of well spacing.

[0041] Furthermore, the dual objective function model for well-average EUR-recovery rate R constructed in step S800 is as follows:

[0042] maxy=F(x)=[f1(x),f2(x),…,f m [x], x∈D;

[0043] in:

[0044] x = (x1, x2, ..., x i ), x i Let i represent the i-th decision variable;

[0045] D represents the n-dimensional decision space;

[0046] F(x) represents m objective component functions that map from the decision space to the solution space;

[0047] f m (x): The m-th objective component of the objective function F(x).

[0048] The present invention also provides a computer terminal storage medium storing computer terminal executable instructions, which are used to execute the above-described method for calculating the reasonable well spacing of shale gas horizontal wells.

[0049] The present invention also provides a computing device, comprising:

[0050] At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the above-described method for calculating the reasonable well spacing of shale gas horizontal wells.

[0051] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0052] This invention constructs and calibrates an integrated numerical simulation model of shale gas development platforms, simulating and calculating the changes in average well EUR (Effective Recovery Rate) and recovery rate with well spacing. It optimizes a single-objective fitting function and constructs a multi-objective function to evaluate average well EUR and recovery rate, ultimately calculating the optimal well spacing for horizontal shale gas wells. Shale gas reservoirs are "continuous" reservoirs, exhibiting a "one well, one reservoir" characteristic during development. Therefore, well spacing significantly impacts the production efficiency of individual wells and the full utilization of block resources. The calculation method in this patent selects the two most important factors in shale gas development as objective functions, providing a more comprehensive justification and more reliable calculation results. The resulting well spacing calculation method is crucial for ensuring gas well production efficiency and avoiding resource waste, and has broad applicability in shale / tight gas development, with promising application prospects. Attached Figure Description

[0053] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a flowchart illustrating the calculation method for the reasonable well spacing of shale gas horizontal wells in an embodiment of the present invention.

[0055] Figure 2 This is a diagram showing the historical fitting results in an embodiment of the present invention.

[0056] Figure 3 This is a graph showing the variation of the average well-to-well EUR with well spacing after dimensionless processing in an embodiment of the present invention.

[0057] Figure 4 This is a graph showing the change of recovery rate R with well spacing after dimensionless processing in an embodiment of the present invention.

[0058] Figure 5 This is a diagram illustrating the fitting process of dimensionless well-average EUR as a function of well spacing in an embodiment of the present invention. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0060] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0061] Example

[0062] like Figure 1 As shown in the figure, this embodiment proposes a method for calculating the reasonable well spacing of shale gas horizontal wells, including the following steps:

[0063] S100, combining 3D seismic data, well logging data, microseismic data, drilling parameters and fracturing operation parameters, establishes an integrated numerical simulation model of platform geology and engineering;

[0064] Input the three-dimensional seismic data, well logging data, microseismic data, drilling parameters, and fracturing operation parameters shown in Table 1 into the numerical simulation software to establish an integrated numerical simulation model of platform geology and engineering.

[0065] Table 1. Basic parameters for establishing the integrated numerical simulation model of platform geology and engineering:

[0066] Parameter type Parameter values Matrix permeability (mD) <![CDATA[1×10 -5 ~1×10 -4 ]]> Horizontal segment length (m) 1506～1660 Porosity (%) 4.04～5 Water saturation (%) 29.4～42.9 Model depth (m) 3812～3908 Hydraulic fracture length (m) 120～150

[0067] S200 uses the Nelder-Mead simplex method to iteratively update the fitting parameters of the integrated numerical simulation model of the platform's geological engineering, thereby fitting the gas production rate and bottom hole pressure of each well in the platform's well group over the past year. Figure 2 As shown, the integrated numerical simulation model of platform geology and engineering is then corrected;

[0068] S300, using the corrected platform geological engineering integrated numerical simulation model, calculate the well-average EUR and recovery rate R at a certain well spacing (300m);

[0069] EUR ave =(EUR1+EUR) 2+ EUR 3+ …+EUR n ) / n=0.81(300m well spacing);

[0070] R = (EUR1 + EUR) 2+ EUR 3+ …+EUR n ) / V OGIP = 32.7% (300m well spacing);

[0071] Based on the corrected platform geological engineering integrated numerical simulation model, S400 platform well group models with different well spacings (350m, 400m, 450m, 500m) were constructed. The average well EUR and recovery rate R under different well spacings were simulated and calculated, as shown in Table 2.

[0072] Table 2. Average well EUR and recovery rate R at different well spacings:

[0073] Well spacing (m) Platform average well volume EUR (100 million units) Recovery rate R (%) 300 0.81 32.27 350 1.02 31.89 400 1.18 31.09 450 1.28 30.02 500 1.33 27.73

[0074] S500 performs dimensionless processing on the average EUR and recovery rate R at different well spacings, so that the average EUR and recovery rate R have the same scale, in order to conduct comprehensive evaluation of multiple indicators:

[0075]

[0076] Table 3. Dimensionless treatment of well-average EUR and recovery rate R:

[0077] Well spacing (m) Dimensionless well average EUR Dimensionless recovery rate 300 0.00 1.00 350 0.40 0.92 400 0.71 0.74 450 0.90 0.50 500 1.00 0.00

[0078] S600, plot the dimensionless values ​​of well-average EUR and recovery rate R as a function of well spacing, as follows: Figure 3 , Figure 4 As shown;

[0079] S700, combining the data variation patterns of average well EUR and recovery rate R with well spacing on the chart, select functions for average well EUR and recovery rate R as a function of well spacing; specifically:

[0080] First, based on the data variation patterns of well-average EUR and recovery rate R with well spacing, a series of functional relationships are initially selected; in this embodiment, the following three are selected:

[0081] The first type: f(x) = a ln[b(xc)] - d;

[0082] The second type: f(x) = a + bx + cx 2 ;

[0083] The third type: f(x) = a + sin(bx + c);

[0084] Then, the data is fitted using the curve fitting module in MATLAB, such as... Figure 5As shown in Tables 4 and 5, the error results of the series function relationships are compared respectively.

[0085] Table 4. Error results of dimensionless well-average EUR fitting:

[0086] Dimensionless EUR fitting relationship Sum of squared errors f(x)=1.558×ln[1.524×(x-244.1)]-3.012 0.002321 <![CDATA[f(x)=-4.587+0.02146x-2.057×10 -5 x 2 ]]> <![CDATA[5.143×10 -5 ]]>

[0087] Table 5. Error results of dimensionless recovery rate R fitting:

[0088] Dimensionless recovery rate fitting relationship Sum of squared errors f(x)=-0.9916sin(0.008335x+2.079) 0.007267 <![CDATA[f(x)=-1.418+0.01573x-2.571×10 -5 x 2 ]]> 0.003383

[0089] Ultimately, a quadratic polynomial with a smaller sum of squared errors was chosen as the representative function of well-average EUR as a function of well spacing and recovery rate R as a function of well spacing.

[0090] S800, based on the functions of average well EUR (Effective Recovery Rate) and recovery rate R (Recovery Rate) as a function of well spacing, constructs a dual objective function model of average well EUR and recovery rate R, maxy = F(x) = [f1(x), f2(x)]. A multi-objective function optimization analysis method is used to determine the Pareto optimal solution, and the reasonable well spacing corresponding to the platform well group is calculated. When F′(x) = 0, x = 402m, the dual objective function model of average well EUR and recovery rate R reaches its maximum value maxy, and the well spacing of 402m is the reasonable well spacing corresponding to the platform well group.

[0091] maxy=F(x)=[f1(x),f2(x)]=6.005+0.03719x-4.628×10 -5 x 2 ;

[0092] F′(x)=0.03719-9.256×10 -5 x = 0;

[0093] x = 402;

[0094] Furthermore, in some embodiments, a computer terminal storage medium is proposed, storing computer terminal executable instructions for executing the method for calculating the reasonable well spacing of shale gas horizontal wells as described in the preceding embodiments. Examples of computer storage media include magnetic storage media (e.g., floppy disks, hard disks, etc.), optical recording media (e.g., CD-ROMs, DVDs, etc.), or memory such as memory cards, ROMs, or RAMs. The computer storage medium can also be distributed across a network-connected computer system, for example, as an application store.

[0095] Furthermore, in some embodiments, a computing device is proposed, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method for calculating the reasonable well spacing of shale gas horizontal wells as described in the preceding embodiments. Examples of computing devices include PCs, tablets, smartphones, or PDAs.

[0096] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for calculating the reasonable well spacing of shale gas horizontal wells, characterized in that, Includes the following steps: S100, combining 3D seismic data, well logging data, microseismic data, drilling parameters and fracturing operation parameters, establishes an integrated numerical simulation model of platform geology and engineering; S200 uses the Nelder-Mead simplex method to iteratively update the fitting parameters of the integrated numerical simulation model of platform geology and engineering, thereby correcting the integrated numerical simulation model of platform geology and engineering. S300, using a calibrated platform geological engineering integrated numerical simulation model, calculates the well-average EUR and recovery rate at a certain well spacing. R ; EUR This indicates the cumulative gas production of a gas well, in units of 10. 8 m 3 ; Based on the corrected integrated numerical simulation model of platform geology and engineering, S400 platform well group models with different well spacings were constructed, and the average well EUR and recovery rate under different well spacings were simulated and calculated. R ; S500, for well-average EUR and recovery rate at different well spacings. R Perform dimensionless processing; S600, plot the dimensionless well-average EUR and recovery rate. R Chart showing the variation of well spacing; S700, combined with well-average EUR and recovery rate R The data variation patterns of the chart with changes in well spacing were analyzed, and the function of average EUR per well as well spacing and recovery rate were selected. R A function that varies with well spacing; S800, based on the function of well-average EUR as a function of well spacing and recovery rate. R A function of well spacing is used to construct the average well-to-well EUR-recovery rate. R A dual objective function model was used, and the Pareto optimal solution was determined by using a multi-objective function optimization analysis method. The reasonable well spacing corresponding to the platform well group was then calculated.

2. The method for calculating the reasonable well spacing of shale gas horizontal wells according to claim 1, characterized in that, In step S300, the average well EUR and recovery rate at a certain well spacing are calculated. R The method is as follows: EUR ave =( EUR 1+ EUR 2+ EUR 3+ …+ EUR n ) / n ； R =( EUR 1+ EUR 2+ EUR 3+ …+ EUR n ) / V OGIP ； in: n This indicates the number of wells, expressed in units of wells. EUR This indicates the cumulative gas production of a gas well, in units of 10. 8 m 3 ; EUR 1~ EUR n They represent the 1st well to the 2nd well. n Cumulative gas production of a well; EUR ave The average wellbore volume is expressed in EUR, with units of 10. 8 m 3 ; R This indicates the recovery rate, expressed in %; V OGIP This represents the original geological reserves of the model, in units of 10. 8 m 3 .

3. The method for calculating the reasonable well spacing of shale gas horizontal wells according to claim 2, characterized in that, In step S500, the well-average EUR and recovery rate under different well spacings are analyzed. R The method for performing dimensionless processing is as follows: Suppose the shale gas development platforms to be evaluated are: a One, denoted as λ ={ λ 1, λ 2,…, λ a }, characteristic parameter indicators include b One, denoted as ζ ={ ζ 1, ζ 2,…, ζ b }, x ij (i=1,2,…, a j=1,2,…, b ) indicates platform λ i Regarding the first j Each indicator value, then a Platforms and b A matrix N consisting of indicators = ( x ij ) b×a This is the evaluation matrix of the set of solutions to the set of indicators; Assume a relatively ideal target shale gas development platform λ 0 pairs of indicators ζ j The attribute value is x 0j The following formula is used to initialize the well-average EUR and recovery rate. R Dimensionless processing: in: S j This represents the standard deviation of the indicator; I 1 represents the set of subscripts of standardized indicators; I 2 represents the set of subscripts of the normalization index.

4. The method for calculating the reasonable well spacing of shale gas horizontal wells according to claim 3, characterized in that, Step S700 includes: First, combine the average well EUR and recovery rate R To understand the data variation patterns of the chart with changes in well spacing, a series of functional relationships were initially selected. Then, the data was fitted using the curve fitting module in MATLAB. The error results of the series of functional relationships were compared, and finally, the function of well-average EUR changing with well spacing and the recovery rate were selected. R A function that varies with well spacing.

5. The method for calculating the reasonable well spacing of shale gas horizontal wells according to claim 4, characterized in that, The series of functional relationships include three types: The first type: f ( x )= a ln[ b ( x - c )]- d ; The second type: f ( x )= a + bx + cx 2 ; The third type: f ( x )= a +sin( bx + c ); in, a , b , c , d These are all fitting coefficients.

6. The method for calculating the reasonable well spacing of shale gas horizontal wells according to claim 5, characterized in that, We selected a functional relationship with a smaller sum of squared errors as the function of well-average EUR versus well spacing and recovery rate. R A function that varies with well spacing.

7. The method for calculating the reasonable well spacing of shale gas horizontal wells according to claim 6, characterized in that, The well-average EUR recovery rate constructed in step S800 R The dual objective function model is as follows: max y = F ( x )=[ f 1( x ), f 2( x ),…, f m ( x )], x ∈D; in: x =( x 1, x 2,…, x i ), x i Indicates the first i One decision variable; D express n Dimensional decision space; F ( x )express m A target component function that maps from the decision space to the solution space; f m ( x ): Objective function F ( x ) m Each target component.

8. A computer terminal storage medium storing computer terminal executable instructions, characterized in that, The computer terminal can execute instructions for performing the calculation method for the reasonable well spacing of shale gas horizontal wells as described in any one of claims 1-7.

9. A computing device, characterized in that, include: At least one processor; The at least one processor is also connected in communication with a memory, wherein the memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method for calculating the reasonable well spacing of shale gas horizontal wells as described in any one of claims 1-7.

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