A method and system for analyzing inter-well connectivity of multi-stage fractured horizontal wells based on interference testing

Abstract

The application provides a multistage fracturing horizontal well multi-well interwell connectivity analysis method and system based on interference well testing, considers uneven fracture distribution and different fracture connectivity states of a shale gas fracturing horizontal well group, establishes a Laplace space multi-well interference well testing analysis model of the multistage fracturing horizontal well based on percolation mechanics and pressure superposition principle, solves the multi-well interference well testing model of the fracturing horizontal well to obtain a Laplace space multistage fracturing well bottom hole pressure solution, carries out numerical inversion on the Laplace space multistage fracturing well bottom hole pressure solution to obtain a real space multistage fracturing horizontal well bottom hole pressure solution, and then uses the real space multistage fracturing well bottom hole pressure solution and measured bottom hole pressure data to carry out fitting inversion to obtain reservoir parameters and fracturing reconstruction parameters. The scheme can overcome the defects of limited application and insufficient operation precision of the prior art, considers the asymmetry and flow conductivity of fractures about the horizontal wellbore in different connectivity states, and is efficient, and gives consideration to calculation stability and timeliness.

Description

Technical Field

[0001] This invention relates to the field of underground fluid mineral mining engineering technology, and in particular to a method and system for analyzing the inter-well connectivity of multi-well fracturing horizontal wells based on interference testing. Background Technology

[0002] Existing research methods for studying inter-well connectivity can be theoretically categorized into static and dynamic analysis methods. Static analysis includes geological research methods such as stratigraphic correlation and detailed reservoir characterization, while dynamic analysis methods include dynamic response analysis, geochemical methods, tracer testing, numerical simulation techniques, injection-production dynamic data inversion methods, and multi-well test analysis.

[0003] The aforementioned static analysis methods study the static connectivity of sand bodies, providing fundamental information on inter-well connectivity, but they are insufficient to accurately reflect inter-well connectivity during actual production. Dynamic response analysis is a relatively simple and commonly used method among dynamic analysis methods, but it only provides qualitative analysis and is heavily influenced by human experience. Geochemical methods and tracer testing are complex, expensive, and may require long-term well shutdowns, impacting normal oilfield production. Numerical simulation technology allows for quantitative analysis, but the initial modeling and history fitting are extremely labor-intensive, and the results may suffer from ambiguity. Injection-production dynamic data inversion technology is a relatively fast method for quantitative analysis, but its physical meaning is somewhat ambiguous, its reliability is insufficient, and its acceptance is low.

[0004] Furthermore, transient pressure analysis is an important method for obtaining reservoir parameters and fracturing parameters. Its core is establishing a reasonable unsteady flow analysis model for multi-stage fracturing horizontal wells, i.e., a multi-well test analysis model. Currently, trilinear flow models, pentalinear flow models, and multi-stage fracturing horizontal well models considering complex fracture distributions are widely used for parameter evaluation of multi-stage fracturing horizontal wells in shale gas reservoirs. Commercial software such as Saphir and Harmony integrate these analysis models. While trilinear and pentalinear flow models can avoid numerically solving fracture flow models, they primarily focus on single-well analysis and cannot consider the impact of fractures in multiple wells on dynamic analysis. Moreover, these models are based on the assumption that all fractures are perfectly symmetrical and uniformly distributed vertical fractures, which has certain limitations in practical applications, resulting in insufficient accuracy of the analysis results.

[0005] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a method for analyzing the inter-well connectivity of multi-stage fracturing horizontal wells based on interference testing. This method overcomes the limitations of existing technologies, such as application restrictions and insufficient computational accuracy. It considers the asymmetry and conductivity of fractures with respect to the horizontal wellbore under different connectivity states, and the calculation method is efficient, balancing computational stability and timeliness. This method utilizes the principles of seepage mechanics and pressure superposition to analyze the non-uniform fracture distribution and connectivity between reservoir wells, establishing a Laplace spatial multi-stage fracturing horizontal well interference testing analysis model. The model is solved to obtain the bottom-hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well. The Laplace spatial multi-stage fracturing horizontal well bottom-hole pressure solution is numerically inverted to obtain the actual spatial multi-stage fracturing horizontal well bottom-hole pressure solution. Finally, the actual spatial multi-stage fracturing horizontal well bottom-hole pressure solution is fitted and inverted with measured bottom-hole pressure data to obtain reservoir parameters and fracturing stimulation parameters. Preferably, in one embodiment, the method includes:

[0007] Step S1: Considering the non-uniform distribution of fractures and different connectivity states between horizontal wells in shale gas fracturing, a Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model is established based on the principles of seepage mechanics and pressure superposition.

[0008] Step S2: Solve the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model to obtain the bottom hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well;

[0009] Step S3: Perform numerical inversion on the bottom hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well to obtain the bottom hole pressure solution of the real spatial multi-stage fracturing horizontal well;

[0010] Step S4: Use the solution of the bottom hole pressure of the multi-stage fracturing horizontal well in the real space and the measured bottom hole pressure data to fit and invert to obtain reservoir parameters and fracturing stimulation parameters.

[0011] Furthermore, in one embodiment, in step S1, based on the multi-well object of the reservoir under study, a number of dimensionless variable numerical models are defined according to the set principles, including dimensionless kernel function, dimensionless bottom hole pressure, fracture dimensionless pressure, time, fracture dimensionless flow intensity, fracture terminal dimensionless flow, fracture dimensionless conductivity, fracture dimensionless fracture length, longitudinal distance, lateral distance, intersection parameters of fracture and wellbore, reservoir width, and reservoir length.

[0012] In an optional embodiment, step S1, in the process of establishing the Laplace spatial multi-stage fracturing horizontal well inter-well interference well test analysis model, includes:

[0013] Establish corresponding fracture flow equations for the excitation well and observation well respectively; identify the connectivity state of the fractures, and establish corresponding fracture end flow equations for the connected and disconnected states of the fractures respectively.

[0014] The coupling equations between the fracture and the wellbore are established based on the defined point source function.

[0015] In one embodiment, the process of solving the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model in step S2 includes:

[0016] The Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model is numerically discretized;

[0017] By setting the point parameters in the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model to the midpoint of the fracture discrete element, a set of linear equations for the flow intensity solution on the discrete element, the flow rate solution at the fracture end, and the bottom hole pressure solution are obtained. The corresponding flow intensity solution on the discrete element, the flow rate solution at the fracture end, and the bottom hole pressure solution are then solved.

[0018] Furthermore, in an optional embodiment, step S3, the process of numerically inverting the bottom hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well, includes:

[0019] The Stehfest numerical inversion method was used to numerically invert the flow intensity solution, fracture end flow solution, and bottom hole pressure solution on the discrete cells of the Laplace space, and obtain the flow intensity solution, fracture end flow solution, and bottom hole pressure solution on the discrete cells of the real space.

[0020] In a preferred embodiment, step S4, the process of fitting and inverting the bottom-hole pressure solution of the real-space multi-stage fracturing horizontal well with the measured bottom-hole pressure data, includes:

[0021] Step S401: Convert the measured bottom hole pressure data into measured bottom hole pseudo pressure data based on the basic PVT parameters of the oil and gas reservoir;

[0022] Step S402: Obtain the theoretical bottom hole pseudo-pressure function based on the defined dimensionless numerical model and the real space bottom hole pressure solution;

[0023] Step S403: Based on the set objective function, the measured bottom hole pseudo-pressure data from step S401 is inverted and fitted using the theoretical bottom hole pseudo-pressure function from step S402 to obtain reservoir parameters and fracturing parameters.

[0024] In one embodiment, in step S401, the measured bottom hole pressure data p is calculated using the pseudo-pressure method according to the following formula. swi(t) is converted into the corresponding measured bottom hole pseudo-pressure data ψ(p) swi (t)):

[0025]

[0026] In the formula, p swi Let μ be the measured bottom hole pressure of the i-th well, μ be the fluid viscosity, and Z be the fluid deviation factor. i This is the fluid deviation factor under the initial pressure.

[0027] Furthermore, in one embodiment, in step S403, the inversion fitting uses the following objective function.

[0028]

[0029] In the formula, Let represent the square of the L2 norm of vector X, where i is the excitation well or any one or more observation wells.

[0030] Based on other aspects of the methods described in any one or more of the foregoing embodiments, the present invention also provides a storage medium storing program code that can implement the methods described in any one or more of the foregoing embodiments.

[0031] Based on the application aspects of the methods described in any one or more of the above embodiments, the present invention also provides a multi-well connectivity analysis system for multi-stage fracturing horizontal wells based on interference testing, which performs the methods described in any one or more of the above embodiments.

[0032] Compared with the closest prior art, the present invention also has the following beneficial effects:

[0033] This invention provides a method and system for analyzing the inter-well connectivity of multi-stage fractured horizontal wells based on interference testing. The method involves: analyzing the non-uniform fracture distribution and connectivity between reservoir wells using seepage mechanics and superposition principles to establish a corresponding Laplace spatial multi-stage fractured horizontal well interference testing analysis model; solving the Laplace spatial multi-stage fractured horizontal well interference testing analysis model to obtain the bottom-hole pressure solution of the Laplace spatial multi-stage fractured horizontal well; numerically inverting the bottom-hole pressure solution of the Laplace spatial multi-stage fractured horizontal well to obtain the bottom-hole pressure solution of the real spatial multi-stage fractured horizontal well; and effectively using the bottom-hole pressure solution of the real spatial multi-stage fractured horizontal well and measured bottom-hole pressure data for fitting and inversion to obtain reservoir parameters and non-uniform fracturing stimulation parameters. This scheme considers different connectivity modes of fractures between any adjacent fractured horizontal wells in a multi-stage fractured horizontal well group, including both direct fracture connectivity and non-connected fractures. Meanwhile, all fracturing fractures are designed with respect to the horizontal wellbore in mind, and all fractures have varying degrees of conductivity. The model solution method provided in this invention is a semi-analytical method, which, compared to numerical solution methods, does not require the construction of complex discrete meshes, resulting in faster solution speeds and higher computational stability.

[0034] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0036] Figure 1 This is a flowchart illustrating a method for analyzing the inter-well connectivity of multi-well horizontal wells based on interference testing, provided in an embodiment of the present invention.

[0037] Figure 2 This is a schematic diagram of a Laplace spatial multi-stage fracturing horizontal well interference test analysis model provided by an embodiment of the present invention, based on the multi-well connectivity analysis method of multi-stage fracturing horizontal wells with interference test.

[0038] Figures 3(a)-3(d) This is a schematic diagram of the pressure characteristics of dimensionless fracture conductivity and dimensionless well spacing variation under two connectivity modes in the multi-well connectivity analysis method for multi-stage fracturing horizontal wells based on interference testing provided in the embodiments of the present invention.

[0039] Figures 4(a)-4(d)This is a flowchart illustrating the double logarithmic characteristics of pressure and pressure derivative under four connectivity modes in the multi-well connectivity analysis method for multi-stage fracturing horizontal wells based on interference testing provided in this embodiment of the invention.

[0040] Figure 5 This is an example diagram of the multi-well management interface of the multi-well connectivity analysis method for multi-stage fracturing horizontal wells based on interference testing provided in this embodiment of the invention;

[0041] Figure 6 This is an example diagram of the data receiving interface of the multi-well connectivity analysis method for multi-stage fracturing horizontal wells based on interference testing provided in this embodiment of the invention;

[0042] Figure 7 This is an example diagram of the interference test analysis function interface in the connectivity analysis interface of the multi-well connectivity analysis method for multi-stage fracturing horizontal wells based on interference test provided in this embodiment of the invention;

[0043] Figure 8 This is a schematic diagram of the structure of a multi-well connectivity analysis system for multi-stage fracturing horizontal wells based on interference testing, provided in another embodiment of the present invention. Detailed Implementation

[0044] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and examples. Those skilled in the art will then fully understand how the present invention uses technical means to solve technical problems and achieve technical effects, and will be able to implement the present invention specifically based on the above-described implementation process. It should be noted that, as long as there is no conflict, the various embodiments and features of the present invention can be combined with each other, and the resulting technical solutions are all within the protection scope of the present invention.

[0045] Although the flowchart describes the operations as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. The order of the operations can be rearranged. A process can terminate when its operation is complete, but it may also have additional steps not included in the diagram. A process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0046] Computer equipment includes user equipment and network equipment. User equipment or clients include, but are not limited to, computers, smartphones, and PDAs (Personal Digital Assistants); network equipment includes, but is not limited to, a single network server, a server group consisting of multiple network servers, or a cloud based on cloud computing consisting of a large number of computers or network servers. Computer equipment can operate independently to implement this invention, or it can connect to a network and implement this invention through interaction with other computer devices within the network. The network in which the computer equipment resides includes, but is not limited to, the Internet, wide area networks (WANs), metropolitan area networks (MANs), local area networks (LANs), and VPN networks.

[0047] The terms “first,” “second,” etc., may be used herein to describe various units, but these units should not be limited by these terms; they are used merely to distinguish one unit from another. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. When a unit is referred to as “connected” or “coupled” to another unit, it may be directly connected or coupled to said other unit, or there may be intermediate units present.

[0048] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms “a” and “an” as used herein are also intended to include the plural. It should also be understood that the terms “comprising” and / or “including” as used herein specify the presence of the stated features, integers, steps, operations, units, and / or components, without excluding the presence or addition of one or more other features, integers, steps, operations, units, components, and / or combinations thereof.

[0049] Currently, existing research methods for studying inter-well connectivity can be theoretically categorized into static and dynamic analysis methods. Static analysis includes geological research methods such as stratigraphic correlation and detailed reservoir characterization, while dynamic analysis methods include dynamic response analysis, geochemical methods, tracer testing, numerical simulation, injection-production dynamic data inversion, and multi-well testing analysis. The aforementioned static analysis methods study the static connectivity of sand bodies, providing fundamental information for inter-well connectivity, but they struggle to accurately reflect connectivity during actual production. Dynamic response analysis is a relatively simple and commonly used method, but it only provides qualitative analysis and is heavily influenced by human experience. Geochemical methods and tracer testing are complex, expensive, and may require prolonged well shutdowns, disrupting normal oilfield production. Numerical simulation allows for quantitative analysis, but the initial modeling and history fitting are labor-intensive, and the results may suffer from ambiguity. Injection-production dynamic data inversion is a relatively fast method for quantitative analysis, but its physical meaning is somewhat ambiguous, its reliability is insufficient, and its acceptance is low.

[0050] In summary, transient pressure analysis is an important method for obtaining reservoir parameters and fracturing parameters. Its core lies in establishing a reasonable unsteady flow analysis model for multi-stage fracturing horizontal wells, i.e., a multi-well test analysis model. Currently, trilinear flow models, pentalinear flow models, and multi-stage fracturing horizontal well models considering complex fracture distributions are widely used for parameter evaluation in multi-stage fracturing horizontal wells of shale gas reservoirs. Commercial software such as Saphir and Harmony integrate these analysis models. While trilinear and pentalinear flow models can avoid numerically solving fracture flow models, they primarily focus on single-well analysis and cannot consider the impact of multi-well interference on dynamic analysis. Furthermore, these models are based on the assumption that all fractures are perfectly symmetrical and uniformly distributed vertical fractures, which has certain limitations in practical applications, resulting in insufficient accuracy of the analysis results.

[0051] The researchers of this invention realized that a multi-stage fractured horizontal well model that considers complex fracture distribution can better characterize and simulate the reservoir seepage situation of multi-stage fractured horizontal wells.

[0052] To address the problems in connectivity analysis and reservoir parameter evaluation of multi-well fracturing horizontal wells in shale gas reservoirs, this invention provides a method for evaluating inter-well connectivity in multi-well fracturing horizontal wells based on interference testing. This invention considers different connectivity modes of fractures between any adjacent wells in a multi-well fracturing horizontal well group, including both direct fracture connectivity and non-connectivity. Simultaneously, all fractures are considered for asymmetry with respect to the horizontal wellbore, and all fractures are considered for different fracture conductivity. The model solution method provided by this invention is a semi-analytical method, which, compared to numerical solution methods, does not require the construction of complex discrete meshes, resulting in faster solution speed and higher computational stability. This invention plays a crucial role in solving problems related to reservoir fluid flow simulation, unsteady well testing analysis, unsteady interference well testing analysis, production data analysis, and productivity well testing analysis in various complex multi-well fracturing horizontal wells and multi-well fracturing horizontal well groups.

[0053] The following describes the detailed flow of the method according to an embodiment of the present invention with reference to the accompanying drawings, the steps of which can be executed in a computer system containing, for example, a set of computer-executable instructions. Although the logical order of the steps is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0054] Example 1

[0055] Figure 1 This diagram illustrates the flow chart of the multi-well connectivity analysis method for multi-stage fracturing horizontal wells based on interference testing provided in Embodiment 1 of the present invention. (Refer to...) Figure 1 As can be seen, the method includes the following steps.

[0056] Step S1: Analyze the non-uniform fracture distribution and connectivity between reservoir wells using the principles of seepage mechanics and pressure superposition, and establish a corresponding Laplace space multi-stage fracturing horizontal well multi-well interference well test analysis model in the Laplace space.

[0057] Step S2: Solve the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model to obtain the bottom hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well;

[0058] Step S3: Perform numerical inversion on the bottom hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well to obtain the bottom hole pressure solution of the real spatial multi-stage fracturing horizontal well;

[0059] Step S4: Use the solution of the bottom hole pressure of the multi-stage fracturing horizontal well in the real space and the measured bottom hole pressure data to fit and invert to obtain reservoir parameters and non-uniform fracturing stimulation parameters.

[0060] This invention provides a method for evaluating the inter-well connectivity of multi-stage fracturing horizontal wells in shale gas reservoirs based on well testing. This method can be used for evaluating reservoir parameters, non-uniform fracturing stimulation parameters, and inter-well connectivity in shale gas reservoirs. The scheme considers different connectivity modes of fracturing fractures between any adjacent wells in a multi-stage fracturing horizontal well group, including both direct and non-connected fractures. Furthermore, all fracturing fractures are considered in relation to the horizontal wellbore, and all fractures are considered to have different fracture conductivity.

[0061] Furthermore, the model solution method provided by this invention is a semi-analytical method, which, compared to numerical solution methods, does not require the construction of complex discrete meshes, resulting in faster solution speed and higher computational stability. This invention plays an important role in solving various complex problems related to reservoir fluid flow simulation, unsteady well test analysis, unsteady disturbance well test analysis, production data analysis, and productivity well test analysis in multi-stage fractured horizontal wells and multi-stage fractured horizontal well groups.

[0062] In this embodiment of the invention, step S1 is first performed to analyze the distribution of fractures between reservoir wells using the principles of seepage mechanics and superposition. A multi-stage fracturing horizontal well interference test analysis model is then established in the Laplace space. The model includes connected fractures and non-connected fractures, and the fractures are either of equal or unequal length.

[0063] In practical applications, without loss of generality, it is assumed that there are m multi-stage fractured horizontal wells in a homogeneous reservoir of uniform thickness, and each multi-stage fractured horizontal well has n... i There are 10 fractures, all with the same height as the reservoir thickness.

[0064] The m multi-stage fractured horizontal wells are numbered 1, 2, ..., m0-1, m0, m0+1, ..., m, where m0 represents the activation well and 1, 2, ..., m0-1, m0+1, ..., m represents the observation well. The n1 fractures in the multi-stage fractured horizontal well numbered 1, 2, ..., n1, the n2 fractures in the multi-stage fractured horizontal well numbered 1, 2, ..., n2, and so on for the m multi-stage fractured horizontal well. m The cracks are numbered 1, 2, ..., n m .

[0065] In a preferred embodiment, in step S1, a number of dimensionless variable numerical models are defined based on the multi-well object of the reservoir under study according to a set principle, including dimensionless kernel function, dimensionless bottom hole pressure, fracture dimensionless pressure, time, fracture dimensionless flow intensity, fracture terminal dimensionless flow, fracture dimensionless conductivity, fracture dimensionless fracture length, longitudinal distance, lateral distance, intersection parameters of fracture and wellbore, reservoir width, and reservoir length.

[0066] Specifically, based on the above definition of multi-well objects, the following related dimensionless numerical models are determined:

[0067] dimensionless kernel function p OD =Kh[ψ(p i )-ψ(p O )] / (1.866q sc μ i B gi ).

[0068] The dimensionless bottom-hole pressure p of the i-th well wiD =Kh[ψ(p i )-ψ(p wi )] / (1.866q sc μ i B gi ).

[0069] The causality pressure p of the j-th fracture in the i-th well fijD =Kh[ψ(p i )-ψ(p fij )] / (1.866q sc μ i B gi ).

[0070] Dimensionless time t D =0.00355Kt / (φμ) i C ti l 2 ).

[0071] The dimensionless flow rate intensity q of the j-th fracture in the i-th well ijD =q ij l / q sc .

[0072] The dimensionless flow rate q at the end of the j-th fracture in the i-th well fijD =q fij / q sc .

[0073] The dimensionless conductivity C of the j-th fracture in the i-th well fijD =(K fij w fij ) / (Kl).

[0074] The dimensionless fracture length x of the j-th fracture in the i-th well fijD =x fij / l.

[0075] Longitudinal dimensionless distance x D =x / l.

[0076] Lateral dimensionless distance y D =y / l.

[0077] The dimensionless position x of the intersection point of the j-th fracture and the wellbore in the i-th well longitudinally. wijD =x wij / l.

[0078] The dimensionless position y of the intersection point of the j-th fracture in the i-th well with the wellbore. wijD =y wij / l.

[0079] Dimensionless width of reservoir x eD =x e / l.

[0080] Dimensionless length y of reservoir eD =y e / l.

[0081] In the formula, B gi C represents the gas volume coefficient at the initial pressure; f C represents the rock compressibility coefficient, 1 / MPa; gi C represents the gas compressibility at initial pressure, 1 / MPa; ti C represents the overall compressibility coefficient under initial pressure. ti =C f +C gi +ρ b B gi V L p L / [φ(p i +p L ) 2 ], 1 / MPa; h represents reservoir thickness, m; p represents pressure, MPa; K represents reservoir permeability, mD; K fij w fij The conductivity of the j-th fracture in the i-th well is represented by mD·m; l represents the reference length in meters; p0 represents the standard atmospheric pressure in MPa; p fij p represents the pressure in the j-th fracture of the i-th well, in MPa. i The initial pressure is expressed in MPa; p L Indicates adsorption pressure, MPa; p O Point source pressure, MPa; p wi q represents the bottom hole pressure of the i-th well, in MPa; ij Let m represent the flow rate intensity of the j-th fracture in the i-th well. 2 / d;q fij m represents the flow rate at the end of the j-th fracture in the i-th well. 3 / d;q sc Indicates the reference flow rate, m 3 / d;t D Indicates time, s; V L Indicates the adsorption capacity, m 3 / kg; x represents the longitudinal distance, in meters; x e Indicates reservoir width, in meters (m); x fij x represents the length of the j-th fracture in the i-th well, in meters. wij y represents the distance parameter between the intersection point of the j-th fracture in the i-th well and the wellbore, in meters; y represents the lateral distance, in meters. e Represents reservoir length, in meters (m); y wij Z represents the distance parameter (m) between the intersection point of the j-th fracture in the i-th well and the wellbore; Z represents the gas deviation factor; Z i The gas deviation factor is represented by φ at the initial pressure; porosity is represented by %; permeability modulus is represented by 1 / MPa; channeling coefficient from pores to fractures in the fracture-pore medium is represented by λ; gas viscosity is represented by mPa·s; μ i The gas viscosity at initial pressure is expressed in mPa·s; ρ b Density of rock, kg / m³ 3 ω represents the storage capacity ratio of fractures in fracture-pore media; ψ(p) represents the pseudo-pressure. MPa.

[0082] Based on the variable numerical model defined above, a multi-well interference well test analysis model for Laplace spatial multi-stage fracturing horizontal wells is established according to the principles of seepage mechanics and pressure superposition.

[0083] In an optional embodiment, the process of establishing a multi-well interference well test analysis model for Laplace spatial multi-stage fracturing horizontal wells includes:

[0084] Establish corresponding fracture flow equations for the excitation well and observation well respectively; identify the connectivity state of the fractures, and establish corresponding fracture end flow equations for the connected and disconnected states of the fractures respectively.

[0085] Based on the defined point source function, the coupling equation between the fracture and the wellbore is established, such as... Figure 2 As shown.

[0086] Specifically, in a preferred embodiment, the equation for the flow rate of the fracture in the excitation well is established as follows:

[0087]

[0088] In the formula, Let q represent the dimensionless flow rate intensity of the j-th fracture in the i-th well. ijD Laplace transform, q fijD The Laplace transform, where s represents the Laplace variable; ni Let α represent the number of fractures in the i-th well; α is the location integral variable.

[0089] The flow rate equation for fractures in the observation well is:

[0090]

[0091] When the cracks are not connected, the flow equation at the crack tip is:

[0092]

[0093] In the formula, set A0 is defined as:

[0094] A0 = {(i,j)|The j-th fracture in the i-th well is a non-connected fracture; i = 1, 2, ..., m; j = 1, 2, ..., n} i}。(4) The flow equation at the fracture terminus when the fractures are connected is:

[0095]

[0096]

[0097] In the formula, p represents the dimensionless bottom hole pressure. wiD Laplace transform, The function representing the conductivity influence of the j-th fracture in the i-th well is used; the set A1 in the formula is defined as...

[0098] The following flow-guiding capacity influence function is adopted.

[0099]

[0100] In the formula, x D ,y D Let X and Y represent dimensionless positions in the X and Y directions, respectively, and v represent the integration variable.

[0101] The coupling equation between the fracture and the wellbore is:

[0102]

[0103] In the formula, u represents the Laplace space function related to the reservoir type. For homogeneous gas reservoirs, u = s; the definition for dual media is given below. The function representing the influence of flow conduction capacity is defined below; This indicates that the Lagrange space at node i has no dimensionless pressure; x eD ,y eD These represent the boundary length and boundary width of the dimensionless model, respectively.

[0104] When point (x D ,y D When on the j-th fracture of the i-th well When point (x D ,y D When it is not on the j-th fracture of the i-th well For point source functions, when the reservoir is a fracture-pore type reservoir, u=s[ω(1-ω)s+λ] / [(1-ω)s+λ], and when the reservoir is a mean reservoir, u=s, where ω represents the storage capacity ratio of fractures in the fracture-pore type medium.

[0105] Preferably, the following point source function can be used.

[0106]

[0107] Next, step S2 is executed to solve the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model to obtain the bottom hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well.

[0108] In an optional embodiment, step S2, which involves solving the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model, includes:

[0109] The Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model is numerically discretized;

[0110] By setting the point parameters in the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model to the midpoint of the fracture discrete element, a set of linear equations for the flow intensity solution on the discrete element, the flow rate solution at the fracture end, and the bottom hole pressure solution are obtained. The corresponding flow intensity solution on the discrete element, the flow rate solution at the fracture end, and the bottom hole pressure solution are then solved.

[0111] In practical applications, the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model is first numerically discretized.

[0112] Specifically, the j-th fracture in the i-th well is divided into N... ij Let there be discrete cells, and assume that the flow intensity within any discrete cell is independent of its location, denoted as .

[0113] Preferably, the j-th fracture in the i-th well is divided into N equal parts. ij If there are discrete units, then

[0114]

[0115] In the formula, i = 1, 2, ..., m; j = 1, 2, ..., n i k = 1, 2, ..., N ij Δx fijD =x fijD / N ij ;k represents the k-th crack discrete element, and correspondingly, N ij This represents the total number of discrete fracture elements in the j-th fracture of the i-th well; This represents the Laplace space production of the j-th fracture in the i-th well.

[0116] Furthermore, the point parameters (x) in the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model are further analyzed. D ,y D ) are successively set to the midpoint of all the discrete elements of the crack, that is, (x) in the above formulas (1)-(9). D ,y D ), can obtain information about The system of linear equations, totaling An unknown quantity Solving the system of equations yields the flow intensity solution for any discrete cell in the Laplace space. Solution of flow at the end of any crack And the bottom hole pressure solution of any well

[0117] Further, step S3 is performed to numerically invert the bottom-hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well to obtain the bottom-hole pressure solution of the real spatial multi-stage fracturing horizontal well.

[0118] In a preferred embodiment, step S3, the process of numerically inverting the bottom hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well, includes:

[0119] The Stehfest numerical inversion method was used to numerically invert the flow intensity solution, fracture end flow solution, and bottom hole pressure solution on the discrete cells of the Laplace space, and obtain the flow intensity solution, fracture end flow solution, and bottom hole pressure solution on the discrete cells of the real space.

[0120] In practical applications, step S3, which involves numerically inverting the bottom-hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well, includes:

[0121] The numerical inversion method is used to obtain the flow intensity solution for any discrete cell in the Laplace space. Solution of flow at the end of any crack And the bottom hole pressure solution of any well Numerical inversion is performed to obtain the flow intensity solution q on any discrete cell in real space. ijD,k (t D ), the flow solution q at the end of any crack fijD (t D And the bottom hole pressure solution p of any well wiD (t D ).

[0122] Preferably, the real-space solution function g(t) D ) and Laplace space solution function The transformation is performed using the following Stehfest numerical inversion method:

[0123]

[0124]

[0125] In the formula, N represents the series of Laplace numerical inversion, which is an even number, generally between 8 and 16. In practical applications, N is usually taken as 8, indicating that the Laplace numerical inversion polynomial series has been calculated up to 8 terms. j represents the index of the current term in the Laplace numerical inversion, z represents the function to be inverted in the Laplace space, s represents the Laplace variable, and t D Let n denote dimensionless time, and n denote the summation of a series within the polynomial.

[0126] Further, step S4 is performed, in which the reservoir parameters and non-uniform fracturing parameters are obtained by fitting and inverting the bottom-hole pressure solution of the real-space multi-stage fracturing horizontal well with the measured bottom-hole pressure data.

[0127] In the optional capability, step S4, the process of fitting and inverting the bottom-hole pressure solution of the real-space multi-stage fracturing horizontal well with the measured bottom-hole pressure data includes:

[0128] Step S401: Convert the measured bottom hole pressure data into measured bottom hole pseudo pressure data based on the basic PVT parameters of the oil and gas reservoir;

[0129] Step S402: Obtain the theoretical bottom hole pseudo-pressure function based on the defined dimensionless numerical model and the real space bottom hole pressure solution;

[0130] Step S403: Based on the set objective function, the theoretical bottom hole pseudo-pressure function described in step S402 is used to invert and fit the measured bottom hole pseudo-pressure data described in step S401 to obtain reservoir parameters and non-uniform fracturing parameters.

[0131] In practical applications, step S4, which involves fitting and inverting the bottom-hole pressure solution of the multi-stage fracturing horizontal well in real space with the measured bottom-hole pressure data, includes:

[0132] S401: Convert measured bottom hole pressure data into measured pseudo-bottom hole pressure data based on the basic PVT parameters of the oil and gas reservoir.

[0133] Preferably, the measured bottom hole pressure data p is calculated using the pseudo-pressure method according to the following formula. swi (t) is converted into the corresponding measured bottom hole pseudo-pressure data ψ(p) swi (t)):

[0134]

[0135] In the formula, p swi Let μ be the measured bottom hole pressure of the i-th well, μ be the fluid viscosity, and Z be the fluid (gas) deviation factor. i t represents the fluid deviation factor under the initial pressure, and t represents time.

[0136] S402: Obtain the theoretical bottom-hole pseudo-pressure function based on the defined dimensionless numerical model and the real-space bottom-hole pressure solution:

[0137]

[0138] S403: Based on the set objective function, the measured bottom-hole pseudo-pressure data from step S401 is inverted and fitted using the theoretical bottom-hole pseudo-pressure function from step S402 to obtain reservoir parameters and non-uniform fracturing parameters. The reservoir parameters include reservoir permeability K and reservoir boundary length y. e reservoir boundary width x e The non-uniform fracturing parameters include fracture length x. fij , fracture conductivity K fij w fij .

[0139] Preferably, the inversion fitting can be performed using the following optimization objective function.

[0140]

[0141] In the formula, Let i represent the square of the second norm of vector X. i can be selected as the excitation well, any observation well, any number of observation wells, the excitation well and any observation well, or the excitation well and any number of observation wells, depending on the actual situation.

[0142] The present invention will be further described below with reference to specific embodiments. The scope of the present invention is not limited to the embodiments, but is defined in the claims.

[0143] Without loss of generality, we will take two multi-stage fractured horizontal wells as examples to conduct a dynamic pressure analysis.

[0144] Well 1 is always shut in, Well 2 produces at a constant rate, and the reservoir has a dimensionless boundary x. eD =y eD =10000, reservoir natural fracture capacity ratio ω=0.1, reservoir matrix channeling coefficient λ=10 -6 Unless otherwise specified in the implementation case, the dimensionless well spacing d between the two wells is... D =2000, dimensionless crack length x fD =800, the dimensionless conductivity C of any fracture in the two wells. fD =2×10 5 The fractures are evenly distributed. When the fractures are connected, the sum of the dimensionless fracture lengths of the two connected fractures is exactly the dimensionless well spacing between the two wells, and the sum of the dimensionless upper and lower fracture lengths of each well is always 1600.

[0145] Figures 3(a)-3(d) The pressure characteristic diagrams of dimensionless fracture conductivity and dimensionless well spacing variation under two connectivity modes provided by the present invention are shown. When the fractures of the two wells are not connected, the different fracture conductivity has almost no effect on the pressure curves of well 1 and well 2. Since well 2 is in production, its bottom hole pressure difference is significantly larger than that of well 1, and the dimensionless pressure corresponding to well 2 is also higher than that of well 1 [Figure 3(a)];

[0146] When the fractures in the two wells are connected (fractures numbered 12 and 21 are connected), the different fracture conductivity has almost no effect on the pressure curves of well 1 and well 2. Although well 1 is always shut in, its lower fracture is directly connected to the upper fracture of well 2, so the pressure responses of the two are almost synchronous [Figure 3(b)].

[0147] When the fractures in the two wells are not connected, different well spacings have a significant impact on the pressure curves of well 1 and well 2. As the well spacing increases, the pressure difference in well 1 decreases, while the pressure difference in well 2 increases [Figure 3(c)];

[0148] When the fractures of the two wells are connected, the different well spacing has little effect on the pressure curves of well 1 and well 2. As the well spacing increases, the pressure difference between well 1 and well 2 decreases synchronously [Figure 3(d)].

[0149] Figure 4 shows the double logarithmic characteristics of pressure and pressure derivative under four connectivity modes provided by this invention. When the number of connected fractures is 0 (fractures are not connected), 2 (fractures numbered 12 and 21 are connected), 4 (fractures numbered 12 and 21 are connected, and fractures numbered 14 and 23 are connected), and 6 (fractures numbered 12 and 21 are connected, fractures numbered 14 and 23 are connected, and fractures numbered 16 and 25 are connected), the double logarithmic characteristics of well 2 show no significant change [see...]. Figures 4(a)-4(d)[Grey curve]. When the number of connected fractures was 2, 4, and 6, the logarithmic characteristics of well 1 showed no significant change [see...]. Figures 4(b)-4(d) Black curve.

[0150] Figure 5 , Figure 6 , Figure 7 These are screenshots of a portion of the interface of the application software provided by this invention. Figure 5 The interface is for managing multiple wells, mainly including adding or deleting wells and configuring fracturing fractures in multiple wells. Figure 6 It serves as a data receiving interface for multiple wells, primarily including the reception of flow and pressure data from multiple wells and the division of data flow segments. Figure 7 To address interference well test analysis functions in the connectivity analysis interface, this mainly includes pressure double logarithmic plots, semi-logarithmic plots, historical forward modeling simulation analysis, and historical inversion fitting analysis for multiple wells.

[0151] As shown in Figure 3, different fracture conductivity has little impact on the bottom hole pressure curves of each well. Different well spacing has a significant impact on the bottom hole pressure curves of each well. As shown in Figure 4, when the fractures of two wells are not connected or interconnected, the logarithmic characteristic diagram of the production well mainly shows early-stage bilinear flow characteristics of the fractures and reservoir, early-mid stage linear flow characteristics of the reservoir, mid-to-late stage radial flow and channeling depression characteristics of the reservoir, and late-stage pseudo-steady-state flow characteristics at the reservoir boundary. When the fractures of two wells are not connected, the logarithmic characteristic diagram of the shut-in well mainly shows early-stage curve intersection, with virtually no bilinear or linear flow characteristic lines. When the fractures of two wells are connected, the logarithmic characteristic diagrams of the shut-in well and the production well are similar, and the greater the fracture conductivity, the higher the degree of similarity.

[0152] When the number of connected fractures is 0 (fractures are not connected), 2 (fractures numbered 12 and 21 are connected), 4 (fractures numbered 12 and 21 are connected, and fractures numbered 14 and 23 are connected), and 6 (fractures numbered 12 and 21 are connected, fractures numbered 14 and 23 are connected, and fractures numbered 16 and 25 are connected), the logarithmic characteristics of Well 2 show no significant change. When the number of connected fractures is 2, 4, and 6, the logarithmic characteristics of Well 1 show no significant change.

[0153] In industrial applications, by plotting the pressure curve and the double logarithmic curve of the pressure derivative of the measured data, this invention can qualitatively determine whether the fractures of two fractured wells are connected by the shape of the curve, and quantitatively analyze reservoir permeability, fracture conductivity and reservoir boundaries by inverting and fitting the pressure curve and the double logarithmic curve of the pressure derivative of the measured data.

[0154] The embodiments given above are preferred examples for implementing the present invention, and the present invention is not limited to the above embodiments. Any non-essential additions or substitutions made by those skilled in the art based on the technical features of the present invention are within the protection scope of the present invention.

[0155] For the foregoing method embodiments, in order to simplify the description, they are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0156] It should be noted that, in other embodiments of the present invention, the method can also combine one or more of the above embodiments to obtain a new method for analyzing the inter-well connectivity of multi-stage fracturing horizontal wells based on interference testing, so as to achieve efficient and accurate analysis of the inter-well connectivity of multi-stage fracturing horizontal wells in reservoirs and provide support for the study of fracturing stimulation parameters.

[0157] Example 2

[0158] It should be noted that, based on the methods in any one or more embodiments of the present invention described above, the present invention also provides a storage medium storing program code that can implement the methods described in any one or more embodiments. When the program code is executed by the operating system, it can implement the multi-well connectivity analysis method for multi-stage fracturing horizontal wells based on interference testing as described above.

[0159] Example 3

[0160] The methods described in the above-disclosed embodiments of the present invention are detailed. These methods can be implemented using various devices or systems. Therefore, based on other aspects of the methods described in any one or more of the above embodiments, the present invention also provides a multi-well connectivity analysis system for multi-stage fracturing horizontal wells based on interference testing. This system is used to execute the multi-well connectivity analysis method for multi-stage fracturing horizontal wells based on interference testing described in any one or more of the above embodiments. Specific embodiments are given below for detailed description.

[0161] Specifically, Figure 8 The diagram shows a schematic representation of the inter-well connectivity analysis system for multi-stage fracturing horizontal wells based on interference testing, provided in an embodiment of the present invention. Figure 8 As shown, the system includes:

[0162] The well test interference model establishment module is configured to consider the non-uniform distribution of fractures and different connectivity states between horizontal wells in shale gas fracturing. Based on the principles of seepage mechanics and pressure superposition, a Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model is established.

[0163] The initial space pressure calculation module is configured to solve the Laplace space multi-stage fracturing horizontal well multi-well interference well test analysis model to obtain the bottom hole pressure solution of the Laplace space multi-stage fracturing horizontal well.

[0164] The real-space pressure inversion module is configured to perform numerical inversion on the bottom-hole pressure solution of the Laplace space multi-stage fracturing horizontal well to obtain the bottom-hole pressure solution of the real-space multi-stage fracturing horizontal well.

[0165] The target parameter acquisition module is configured to obtain reservoir parameters and fracturing stimulation parameters by fitting and inverting the bottom-hole pressure solution of the real-space multi-stage fracturing horizontal well with the measured bottom-hole pressure data.

[0166] Furthermore, in one embodiment, the well test interference model establishment module is configured to: define multiple dimensionless variable numerical models based on the multi-well object of the reservoir under study according to a set principle, including dimensionless kernel function, dimensionless bottom hole pressure, fracture dimensionless pressure, time, fracture dimensionless flow intensity, fracture terminal dimensionless flow, fracture dimensionless conductivity, fracture dimensionless fracture length, longitudinal distance, lateral distance, fracture-wellbore intersection location parameters, reservoir width, and reservoir length.

[0167] In an optional embodiment, the well test interference model establishment module establishes a multi-well interference well test analysis model for Laplace spatial multi-stage fracturing horizontal wells according to the following operations:

[0168] Establish corresponding fracture flow equations for the excitation well and observation well respectively; identify the connectivity state of the fractures, and establish corresponding fracture end flow equations for the connected and disconnected states of the fractures respectively.

[0169] The coupling equations between the fracture and the wellbore are established based on the defined point source function.

[0170] In one embodiment, the initial space pressure calculation module solves the Laplace space multi-stage fracturing horizontal well multi-well interference well test analysis model according to the following operations:

[0171] The Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model is numerically discretized;

[0172] By setting the point parameters in the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model to the midpoint of the fracture discrete element, a set of linear equations for the flow intensity solution on the discrete element, the flow rate solution at the fracture end, and the bottom hole pressure solution are obtained. The corresponding flow intensity solution on the discrete element, the flow rate solution at the fracture end, and the bottom hole pressure solution are then solved.

[0173] Further, in an optional embodiment, the process by which the real-space pressure inversion module performs numerical inversion on the bottom-hole pressure solution of the Laplace space multi-stage fracturing horizontal well includes:

[0174] The Stehfest numerical inversion method was used to numerically invert the flow intensity solution, fracture end flow solution, and bottom hole pressure solution on the discrete cells of the Laplace space, and obtain the flow intensity solution, fracture end flow solution, and bottom hole pressure solution on the discrete cells of the real space.

[0175] In a preferred embodiment, the target parameter acquisition module performs a fitting and inversion operation using the bottom-hole pressure solution of the real-space multi-stage fracturing horizontal well and the measured bottom-hole pressure data as follows:

[0176] Based on the basic PVT parameters of the oil and gas reservoir, the measured bottom hole pressure data is converted into measured pseudo-bottom hole pressure data.

[0177] The theoretical bottom-hole pseudo-pressure function is obtained based on the defined dimensionless variable numerical model and the real space bottom-hole pressure solution.

[0178] Based on the set objective function, the measured bottom hole pressure data are inverted and fitted using the theoretical bottom hole pressure function to obtain reservoir parameters and fracturing parameters.

[0179] In one embodiment, when the target parameter acquisition module converts the measured bottom hole pressure data into measured bottom hole pseudo-pressure data, it uses the pseudo-pressure method to convert the measured bottom hole pressure data p into measured bottom hole pressure data according to the following formula. swi (t) is converted into the corresponding measured bottom hole pseudo-pressure data ψ(p) swi (t)):

[0180]

[0181] In the formula, p swi Let μ be the measured bottom hole pressure of the i-th well, μ be the fluid viscosity, and Z be the fluid deviation factor. i This is the fluid deviation factor under the initial pressure.

[0182] Furthermore, in one embodiment, during the process of obtaining reservoir parameters and fracturing stimulation parameters, the target parameter acquisition module uses the following objective function for inversion fitting:

[0183]

[0184] In the formula, Let represent the square of the L2 norm of vector X, where i is the excitation well or any one or more observation wells.

[0185] In the multi-well connectivity analysis system for multi-stage fracturing horizontal wells based on interference testing provided in this embodiment of the invention, each module or unit structure can operate independently or in combination according to actual parameter definition requirements and model establishment and settlement requirements to achieve the corresponding technical effects.

[0186] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should be extended to equivalent substitutions of these features as understood by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0187] The phrase "an embodiment" in the specification means that a specific feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0188] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for analyzing the inter-well connectivity of multi-well horizontal wells based on interference testing, characterized in that, The method includes: Step S1: Considering the non-uniform distribution of fractures and different connectivity states between horizontal wells in shale gas fracturing, a Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model is established based on the principles of seepage mechanics and pressure superposition. Step S2: Solve the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model to obtain the bottom hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well; Step S3: Perform numerical inversion on the bottom hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well to obtain the bottom hole pressure solution of the real spatial multi-stage fracturing horizontal well; Step S4: Use the solution of the bottom hole pressure of the multi-stage fracturing horizontal well in the real space and the measured bottom hole pressure data to fit and invert to obtain reservoir parameters and fracturing stimulation parameters.

2. The method according to claim 1, characterized in that, In step S1, based on the multi-well object of the research reservoir, a number of dimensionless variable numerical models are defined according to the set principles, including dimensionless kernel function, dimensionless bottom hole pressure, fracture dimensionless pressure, time, fracture dimensionless flow intensity, fracture terminal dimensionless flow, fracture dimensionless conductivity, fracture dimensionless fracture length, longitudinal distance, lateral distance, intersection parameters of fracture and wellbore, reservoir width, and reservoir length.

3. The method according to claim 1, characterized in that, In step S1, the process of establishing the Laplace spatial multi-stage fracturing horizontal well inter-well interference well test analysis model includes: Establish corresponding fracture flow equations for the excitation well and observation well respectively; identify the connectivity state of the fractures, and establish corresponding fracture end flow equations for the connected and disconnected states of the fractures respectively. The coupling equations between the fracture and the wellbore are established based on the defined point source function.

4. The method according to claim 1, characterized in that, Step S2 involves solving the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model, which includes: The Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model is numerically discretized; By setting the point parameters in the Laplace spatial multi-stage fracturing horizontal well multi-well interference well test analysis model to the midpoint of the fracture discrete element, a set of linear equations for the flow intensity solution on the discrete element, the flow rate solution at the fracture end, and the bottom hole pressure solution are obtained. The corresponding flow intensity solution on the discrete element, the flow rate solution at the fracture end, and the bottom hole pressure solution are then solved.

5. The method according to claim 1, characterized in that, Step S3, the process of numerically inverting the bottom hole pressure solution of the Laplace spatial multi-stage fracturing horizontal well, includes: The Stehfest numerical inversion method was used to numerically invert the flow intensity solution, fracture end flow solution, and bottom hole pressure solution on the discrete cells of the Laplace space, and obtain the flow intensity solution, fracture end flow solution, and bottom hole pressure solution on the discrete cells of the real space.

6. The method according to claim 1, characterized in that, Step S4, the process of fitting and inverting the bottom-hole pressure solution of the real-space multi-stage fracturing horizontal well with the measured bottom-hole pressure data, includes: Step S401: Convert the measured bottom hole pressure data into measured bottom hole pseudo pressure data based on the basic PVT parameters of the oil and gas reservoir; Step S402: Obtain the theoretical bottom hole pseudo-pressure function based on the defined dimensionless numerical model and the real space bottom hole pressure solution; Step S403: Based on the set objective function, the measured bottom hole pseudo-pressure data from step S401 is inverted and fitted using the theoretical bottom hole pseudo-pressure function from step S402 to obtain reservoir parameters and fracturing parameters.

7. The method according to claim 1, characterized in that, In step S401, the measured bottom hole pressure data p is calculated using the pseudo-pressure method according to the following formula. swi (t) is converted into the corresponding measured bottom hole pseudo-pressure data ψ(pswi(t)): In the formula, p swi Let μ be the measured bottom hole pressure of the i-th well, μ be the fluid viscosity, and Z be the fluid deviation factor. i This is the fluid deviation factor under the initial pressure.

8. The method according to claim 1, characterized in that, In step S403, the inversion fitting uses the following objective function. In the formula, Let represent the square of the L2 norm of vector X, where i is the excitation well or any one or more observation wells.

9. A storage medium, characterized in that, The storage medium stores program code that can implement the method as described in any one of claims 1 to 8.

10. A multi-well connectivity analysis system for multi-stage fracturing horizontal wells based on interference testing, characterized in that, The system performs the method as described in any one of claims 1 to 8.

Images