A method and system for accurately determining the permeability effective stress coefficient of deep unconventional tight reservoirs and decoupling multiple mechanisms
By constructing a continuous permeability evolution surface in deep unconventional tight reservoirs, identifying the permeability rebound boundary, and decoupling the contributions of slippage and adsorption effects, the shortcomings of existing permeability calculation and decoupling methods are addressed, achieving physical realism of the permeability evolution model and improving safety and efficiency in the later stages of gas production.
Patent Information
- Application Number
- CN202610314753.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-16
- Publication Date
- 2026-06-23
AI Technical Summary
Existing permeability calculation and decoupling methods are difficult to take into account the individual production characteristics of different reservoirs, resulting in distorted drainage time predictions in complex geological areas. Furthermore, it is difficult to eliminate the interference of gas slippage effect under high ground stress, which affects extraction safety and production efficiency.
By introducing non-adsorbed and adsorbed gases into reservoir rock samples, and under multiple combinations of confining pressure and pore pressure, the apparent permeability was obtained, a continuous evolution surface of permeability was constructed, the permeability rebound boundary was identified, and the slip effect control zone and the effective stress control zone were divided. Their respective contribution ratios and parameters were then derived, thus achieving decoupling of multiple mechanisms.
This improved the physical realism of the permeability evolution model, significantly enhanced safety and production efficiency in the later stages of gas production, and provided a precise basis for permeability enhancement and extraction decisions.
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Figure CN122257808A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of unconventional tight natural gas development technology, and in particular relates to a method and system for accurately measuring the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling multiple mechanisms. Background Technology
[0002] The evolution of permeability is a core basis for evaluating the extraction efficiency of unconventional tight natural gas and formulating permeability enhancement measures. During reservoir pressure depletion, permeability changes are driven by a combination of physical mechanisms, including effective stress compression, gas slippage, and matrix adsorption / desorption deformation. However, existing permeability calculation and decoupling methods face challenges in engineering practice: the differences in pore structure between primary coal and tectonic coal reservoirs lead to different responses to stress and adsorption, making it difficult for existing unified calculation methods to take into account the individual production characteristics of different reservoirs. Simply assuming an effective stress coefficient of 1 based on porous elasticity theory will result in severe distortion of drainage time predictions in complex geological areas such as fault zones and tectonic zones, easily leading to coal and gas outburst accidents due to incomplete pre-drainage, affecting extraction safety and production efficiency.
[0003] Currently, laboratories typically use the permeability contour method to determine the effective stress coefficient. However, this method struggles to eliminate the interference of gas slippage under high geostress, leading to significant biases in stress sensitivity evaluation. Furthermore, existing studies largely attribute the permeability rebound phenomenon observed in the later stages of extraction to the desorption and shrinkage effects of the adsorbed rock matrix, often neglecting the substantial contribution of the slippage effect. In fact, as extraction depth increases, gas flow in the micro- and nano-pores of deep, tight reservoirs becomes increasingly significant, and the slippage effect may even become one of the dominant factors driving permeability rebound during the low-pressure phase. Therefore, scientifically defining the physical boundary between stress, adsorption, and slippage, and quantitatively decoupling the respective contribution weights of the slippage and adsorption effects, are pressing challenges that need to be addressed in relation to the permeability rebound phenomenon in the later stages of extraction. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention proposes a method for accurately determining the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling multiple mechanisms, comprising: Non-adsorbent gas and adsorbent gas were introduced into the reservoir rock sample respectively. Under multiple combinations of confining pressure and pore pressure, the first apparent permeability of the non-adsorbent gas and the second apparent permeability of the adsorbent gas were obtained respectively. Based on the first apparent permeability, the permeability rebound boundary is identified by modeling the continuous evolution surface of permeability, and the pressure space formed by the confining pressure and the pore pressure is divided into the slip effect control zone and the effective stress control zone. Within the slippage effect control region, the effective stress coefficient and the first slippage factor are derived based on the first apparent permeability. Within the effective stress control region, the stress sensitivity coefficient of the adsorbed gas is derived based on the effective stress coefficient and the second apparent permeability. The inherent permeability of the adsorbed gas is calculated based on the first slippage factor and the second apparent permeability. An inherent permeability model is set up, and the internal expansion coefficient is inverted based on the inherent permeability of the adsorbed gas, the stress sensitivity coefficient, and the effective stress coefficient. Based on the stress sensitivity coefficient and the internal expansion coefficient, the ratios between the contribution ratios of the slippage effect, the stress effect, and the adsorption deformation effect are calculated to determine the main control stage of the reservoir extraction cycle.
[0005] Furthermore, permeability continuous evolution surface modeling is performed to identify permeability rebound boundaries, and the pressure space formed by the confining pressure and the pore pressure is divided into the slip effect control region and the effective stress control region. This includes constructing a Box-Cox transformation of the first apparent permeability, with transformation coefficients of... Construct the first apparent penetration rate about The quadratic response surface equation: in, The first fitting coefficient, The second fitting coefficient, The confining pressure, The third fitting coefficient, The pore pressure, The fourth fitting coefficient, The fifth fitting coefficient, The sixth fitting coefficient; The permeability continuous evolution surface is modeled using the quadratic response surface equation. Multiple rebound extreme points are identified on the permeability continuous evolution surface. All the rebound extreme points are connected to form the permeability rebound boundary. The pressure space after the rebound is divided into the slippage effect control zone, and the pressure space before the rebound is divided into the effective stress control zone.
[0006] Furthermore, based on the first apparent permeability, the effective stress coefficient and the first slip factor are derived by: setting... , For effective stress, and the first apparent penetration rate Substituting into the quadratic response surface equation, the effective stress coefficient can be derived. ; By constructing the first apparent penetration rate about The first slip factor is derived from the quadratic Klinkenberg model.
[0007] Furthermore, based on the effective stress coefficient and the second apparent permeability, the stress sensitivity coefficient of the adsorbed gas is derived by: setting an exponential model for the second apparent permeability: The second apparent penetration rate Reference state inherent penetration rate and the effective stress coefficient Substituting into the exponential model, the stress sensitivity coefficient of the adsorbed gas can be derived. .
[0008] Furthermore, calculating the inherent permeability of the adsorbed gas based on the first slip factor and the second apparent permeability includes: in, The inherent permeability of the adsorbed gas. This is the second apparent penetration rate. The first slip factor, The pore pressure is [value missing].
[0009] Furthermore, the inherent permeability model includes: in, This is the stress sensitivity coefficient. The effective stress coefficient is... For elastic modulus, The internal expansion coefficient is [value missing]. This represents the maximum adsorption deformation of the matrix in the reservoir rock sample. Poisson's ratio, The pressure required to achieve half of the maximum adsorption deformation.
[0010] Furthermore, based on the stress sensitivity coefficient and the internal expansion coefficient, the ratios between the contribution percentages of the slippage effect, the stress effect, and the adsorption deformation effect are calculated, including: in, Contribution to the slippage effect The proportion of the stress effect The proportion of the adsorption deformation effect. The confining pressure is the aforementioned pressure.
[0011] Furthermore, it also includes: dividing the adsorption deformation effect control stage and the stress effect control stage by the apparent effective stress, and when the apparent effective stress corresponds to the apparent effective stress coefficient When the value is greater than 0, it is the stage where the stress effect dominates. When the apparent effective stress corresponds to the apparent effective stress coefficient, When the value is less than 0, it is the stage where the adsorption deformation effect is the main control. Calculate the apparent effective stress coefficient include: .
[0012] Furthermore, when the contribution ratio of the slippage effect and the contribution ratio of the adsorption deformation effect are equal, the corresponding pore pressure is taken as the critical pressure. If the current pore pressure is greater than the critical pressure, it is the adsorption deformation control stage; if the current pore pressure is less than the critical pressure, it is the slippage effect control stage.
[0013] This invention also proposes a system for accurately determining the effective stress coefficient of permeability in deep unconventional tight reservoirs and for decoupling multiple mechanisms, comprising: An apparent permeability acquisition module is used to introduce non-adsorbed gas and adsorbed gas into reservoir rock samples respectively, and to acquire the first apparent permeability of the non-adsorbed gas and the second apparent permeability of the adsorbed gas under multiple combinations of confining pressure and pore pressure. The region division module is used to identify the permeability rebound boundary based on the first apparent permeability by modeling the continuous evolution surface of permeability, and to divide the pressure space formed by the confining pressure and the pore pressure into the slip effect control zone and the effective stress control zone. The inversion module is used to invert the effective stress coefficient and the first slip factor based on the first apparent permeability within the slip effect control region; to invert the stress sensitivity coefficient of the adsorbed gas based on the effective stress coefficient and the second apparent permeability within the effective stress control region; and to calculate the inherent permeability of the adsorbed gas based on the first slip factor and the second apparent permeability. The model setting module is used to set the inherent permeability model and, based on the inherent permeability of the adsorbed gas, the stress sensitivity coefficient, and the effective stress coefficient, to inversely calculate the internal expansion coefficient. The stage division module is used to calculate the ratio between the contribution ratio of slippage effect, the contribution ratio of stress effect, and the contribution ratio of adsorption deformation effect based on the stress sensitivity coefficient and the internal expansion coefficient, thereby dividing the main control stage of the reservoir extraction cycle.
[0014] Compared with the prior art, the present invention has the following advantages and technical effects: 1. This invention constructs a continuous permeability evolution surface using the response surface methodology, combined with a pressure-segmented optimal fitting strategy, effectively avoiding the drawbacks of traditional contour methods in eliminating gas slippage interference in low-pressure regions. The effective stress coefficient κ obtained through iterative optimization inversion can accurately reflect the physical characteristics caused by clay mineral infilling and non-uniform deformation of the dual-pore structure, providing a high-confidence basic parameter for evaluating deep geostress sensitivity.
[0015] 2. This invention, based on the principle of strain superposition, introduces an internal expansion coefficient f and combines it with cross-gas type slippage parameter correlation and migration technology to achieve a quantitative separation of the contributions of stress sensitivity, adsorption deformation, and slippage effect to permeability. This effectively solves the problem of unclear attribution and mutual interference between the two mechanisms of slippage enhancement and adsorption contraction in the later stages of gas production, significantly improving the physical accuracy of permeability evolution models and production capacity predictions.
[0016] 3. This invention, by quantitatively calculating the dynamic contribution ratio of the three mechanisms, scientifically divides the entire life cycle of unconventional tight natural gas extraction into three core stages: stress-dominated, adsorption-dominated, and slippage-dominated. This provides a decision-making basis for shale gas development and precise on-site coal mine implementation, effectively reducing the blindness of permeability enhancement extraction projects: large-scale fracturing or depressurization can be implemented in the stress-dominated stage; thermal or gas injection can be used to enhance desorption in the adsorption-dominated stage; and negative pressure regulation can be strengthened in the slippage-dominated stage. Attached Figure Description
[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart of the method in Embodiment 1 of the present invention; Figure 2 This is a system structure diagram of Embodiment 2 of the present invention; Figure 3 This is a continuous evolution surface diagram of permeability according to the present invention; Figure 4 (a) is a schematic diagram of Klinkenberg when the effective stress coefficient is 1; Figure 4 (b) is a schematic diagram of Klinkenberg stress when the effective stress coefficient is 2.7; Figure 5 (a) is a schematic diagram showing the change of inherent methane permeability with pore pressure; Figure 5 (b) is a schematic diagram showing the change of the internal expansion coefficient of methane in this invention with pore pressure; Figure 6 This is a schematic diagram illustrating the contribution rates of the methane stress effect, slippage effect, and adsorption deformation effect in this invention. Detailed Implementation
[0018] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0019] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.
[0020] Example 1 like Figure 1 As shown in the figure, this embodiment proposes a method for accurate determination of the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling of multiple mechanisms, which specifically includes the following steps: In step S1, non-adsorbent gas and adsorbent gas are introduced into the reservoir rock sample respectively. Under multiple combinations of confining pressure and pore pressure, the first apparent permeability of the non-adsorbent gas and the second apparent permeability of the adsorbent gas are obtained respectively. For example, in this embodiment, the non-adsorbent gas is helium and the adsorbent gas is methane. After helium and methane are introduced into the reservoir rock sample respectively, the steady-state method is used for testing. After the gas outflow rate monitored by the flow meter reaches a steady state, the first apparent permeability of helium and the second apparent permeability of methane are recorded.
[0021] Step S2, based on the first apparent permeability, identifies the permeability rebound boundary (e.g., by modeling a continuous evolution surface of permeability) through permeability modeling. Figure 3 As shown), the pressure space formed by the confining pressure and the pore pressure is divided into the slip effect control region and the effective stress control region; Specifically, permeability continuous evolution surface modeling, identifying permeability rebound boundaries, and dividing the pressure space formed by the confining pressure and the pore pressure into the slip effect control region and the effective stress control region includes: constructing a Box-Cox transformation of the first apparent permeability, with transformation coefficients of... Construct the first apparent penetration rate about The quadratic response surface equation: in, The first fitting coefficient, The second fitting coefficient, The confining pressure, The third fitting coefficient, The pore pressure, The fourth fitting coefficient, The fifth fitting coefficient, The sixth fitting coefficient; The permeability continuous evolution surface is modeled using the quadratic response surface equation, and multiple rebound extreme points are identified on the permeability continuous evolution surface (based on...). Figure 3 As shown in the diagram on the right, the points on each line first decrease, then increase again at the lowest point (therefore, the lowest point is the rebound extreme point). Connecting all the rebound extreme points forms the permeability rebound boundary. The pressure space after the rebound is divided into the slippage effect control zone, and the pressure space before the rebound is divided into the effective stress control zone. Preferably, the permeability rebound boundary satisfies: .
[0022] Step S3: Within the slippage effect control region, the effective stress coefficient and the first slippage factor are derived based on the first apparent permeability. Within the effective stress control region, the stress sensitivity coefficient of the adsorbed gas is derived based on the effective stress coefficient and the second apparent permeability. The inherent permeability of the adsorbed gas is calculated based on the first slippage factor and the second apparent permeability. Specifically, based on the first apparent permeability, the effective stress coefficient and the first slip factor are derived by setting: ( (for effective stress), and the first apparent penetration rate Substituting into the quadratic response surface equation, the effective stress coefficient can be derived. ; By constructing the first apparent penetration rate about The first slip factor is derived from the quadratic Klinkenberg model, where the quadratic Klinkenberg model is: in, The slip coefficient, This is the second slip coefficient.
[0023] Preferred, such as Figure 4 (a) and Figure 4 As shown in (b), this embodiment employs an optimal slip effect fitting method (e.g., first setting different effective stress coefficients, and then fitting the best effective stress coefficient) for the slip effect control region, regarding the pore pressure within the slip effect control region. To control a constant effective stress, the confining pressure is set as follows: Obtained through the quadratic response surface equation Corresponding first apparent penetration rate Thus establishing about The quadratic Klinkenberg model, where the Klinkenberg slip factor can be expressed as... .
[0024] Specifically, the stress sensitivity coefficient of the adsorbed gas is derived from the effective stress coefficient and the second apparent permeability by: setting an exponential model for the second apparent permeability: The second apparent penetration rate Reference state inherent penetration rate and the effective stress coefficient Substituting into the exponential model, the stress sensitivity coefficient of the adsorbed gas can be derived. .
[0025] Specifically, based on the first slip factor and the second apparent permeability, the inherent permeability of the adsorbed gas is calculated, and the calculation results are illustrated in the diagram below. Figure 5 As shown in (a), it specifically includes: in, The inherent permeability of the adsorbed gas. This is the second apparent penetration rate. The first slip factor, The pore pressure is [value missing].
[0026] Step S4 sets up an inherent permeability model, and calculates the internal expansion coefficient based on the inherent permeability of the adsorbed gas, the stress sensitivity coefficient, and the effective stress coefficient. Specifically, the inherent penetration rate model includes: in, This is the stress sensitivity coefficient. The effective stress coefficient is... For elastic modulus, The internal expansion coefficient (ranging from 0 to 1) is the internal expansion coefficient. As pore pressure changes, Figure 5 As shown in (b), This represents the maximum adsorption deformation of the matrix in the reservoir rock sample. Poisson's ratio, The pressure required to achieve half of the maximum adsorption deformation.
[0027] Preferably, in this embodiment, the maximum adsorption deformation of the reservoir rock sample matrix is obtained by fitting a Langmuir-type empirical formula through a methane adsorption strain experiment on the reservoir rock sample matrix. and the pressure at which half of the maximum adsorption deformation is reached. ， The empirical formula for Langmuir type is: in, To the pore pressure The volumetric adsorption strain below.
[0028] Step S5 calculates the ratios between the contribution percentages of the slippage effect, stress effect, and adsorption deformation effect based on the stress sensitivity coefficient and the internal expansion coefficient, thereby dividing the main control stage of the reservoir extraction cycle.
[0029] Specifically, such as Figure 6 The ratios calculated based on the stress sensitivity coefficient and the internal expansion coefficient, among the contribution percentages of the slippage effect, stress effect, and adsorption deformation effect, include: in, Contribution to the slippage effect The proportion of the stress effect The proportion of the adsorption deformation effect. The confining pressure is the aforementioned pressure.
[0030] Specifically, the adsorption deformation effect control stage and the stress effect control stage are divided by the apparent effective stress. When the value is greater than 0, it is the stage where the stress effect dominates. When the apparent effective stress corresponds to the apparent effective stress coefficient, When the value is less than 0, it is the stage where the adsorption deformation effect is the main control. Calculate the apparent effective stress coefficient include: .
[0031] Specifically, when the contribution ratio of the slippage effect and the contribution ratio of the adsorption deformation effect are equal, the corresponding pore pressure is taken as the critical pressure. If the current pore pressure is greater than the critical pressure, it is the adsorption deformation control stage. If the current pore pressure is less than the critical pressure, it is the slippage effect control stage.
[0032] Preferably, this embodiment also includes an apparent permeability model for predicting apparent permeability, specifically including: in, Pore pressure under reference conditions, The confining pressure is the reference pressure.
[0033] Example 2 like Figure 2 As shown in the figure, this embodiment proposes a system for accurate determination of the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling from multiple mechanisms, which specifically includes the following modules: An apparent permeability acquisition module is used to introduce non-adsorbed gas and adsorbed gas into reservoir rock samples respectively, and to acquire the first apparent permeability of the non-adsorbed gas and the second apparent permeability of the adsorbed gas under multiple combinations of confining pressure and pore pressure. The region division module is used to identify the permeability rebound boundary based on the first apparent permeability by modeling the continuous evolution surface of permeability, and to divide the pressure space formed by the confining pressure and the pore pressure into the slip effect control zone and the effective stress control zone. The inversion module is used to invert the effective stress coefficient and the first slip factor based on the first apparent permeability within the slip effect control region; to invert the stress sensitivity coefficient of the adsorbed gas based on the effective stress coefficient and the second apparent permeability within the effective stress control region; and to calculate the inherent permeability of the adsorbed gas based on the first slip factor and the second apparent permeability. The model setting module is used to set the inherent permeability model and, based on the inherent permeability of the adsorbed gas, the stress sensitivity coefficient, and the effective stress coefficient, to inversely calculate the internal expansion coefficient. The stage division module is used to calculate the ratio between the contribution ratio of slippage effect, the contribution ratio of stress effect, and the contribution ratio of adsorption deformation effect based on the stress sensitivity coefficient and the internal expansion coefficient, thereby dividing the main control stage of the reservoir extraction cycle.
[0034] Since the system technical solution of this embodiment 2 is based on the technical solution of embodiment 1, it will not be described again.
[0035] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A method for accurately determining the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling multiple mechanisms, characterized in that, include: Non-adsorbent gas and adsorbent gas were introduced into the reservoir rock sample respectively. Under multiple combinations of confining pressure and pore pressure, the first apparent permeability of the non-adsorbent gas and the second apparent permeability of the adsorbent gas were obtained respectively. Based on the first apparent permeability, the permeability rebound boundary is identified by modeling the continuous evolution surface of permeability, and the pressure space formed by the confining pressure and the pore pressure is divided into the slip effect control zone and the effective stress control zone. Within the slippage effect control region, the effective stress coefficient and the first slippage factor are derived based on the first apparent permeability. Within the effective stress control region, the stress sensitivity coefficient of the adsorbed gas is derived based on the effective stress coefficient and the second apparent permeability. The inherent permeability of the adsorbed gas is calculated based on the first slippage factor and the second apparent permeability. An inherent permeability model is set up, and the internal expansion coefficient is inverted based on the inherent permeability of the adsorbed gas, the stress sensitivity coefficient, and the effective stress coefficient. Based on the stress sensitivity coefficient and the internal expansion coefficient, the ratios between the contribution ratios of the slippage effect, the stress effect, and the adsorption deformation effect are calculated to determine the main control stage of the reservoir extraction cycle.
2. The method for accurate determination of effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling of multiple mechanisms as described in claim 1, characterized in that, Permeability continuous evolution surface modeling, identifying permeability rebound boundaries, and dividing the pressure space formed by the confining pressure and the pore pressure into the slip effect control region and the effective stress control region include: constructing a Box-Cox transformation on the first apparent permeability, with transformation coefficients of... Construct the first apparent penetration rate about The quadratic response surface equation: in, The first fitting coefficient, The second fitting coefficient, The confining pressure, The third fitting coefficient, The pore pressure, The fourth fitting coefficient, The fifth fitting coefficient, The sixth fitting coefficient; The permeability continuous evolution surface is modeled using the quadratic response surface equation. Multiple rebound extreme points are identified on the permeability continuous evolution surface. All the rebound extreme points are connected to form the permeability rebound boundary. The pressure space after the rebound is divided into the slippage effect control zone, and the pressure space before the rebound is divided into the effective stress control zone.
3. The method for accurate determination of the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling of multiple mechanisms as described in claim 2, characterized in that, Based on the first apparent permeability, the effective stress coefficient and the first slip factor are derived by setting: , For effective stress, and the first apparent penetration rate Substituting into the quadratic response surface equation, the effective stress coefficient can be derived. ; By constructing the first apparent penetration rate about The first slip factor is derived from the quadratic Klinkenberg model.
4. The method for accurate determination of the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling of multiple mechanisms as described in claim 3, characterized in that, Based on the effective stress coefficient and the second apparent permeability, the stress sensitivity coefficient of the adsorbed gas is derived by setting an exponential model for the second apparent permeability: The second apparent penetration rate Reference state inherent penetration rate and the effective stress coefficient Substituting into the exponential model, the stress sensitivity coefficient of the adsorbed gas can be derived. .
5. The method for accurate determination of the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling of multiple mechanisms as described in claim 1, characterized in that, The inherent permeability of the adsorbed gas is calculated based on the first slip factor and the second apparent permeability, including: in, The inherent permeability of the adsorbed gas. This is the second apparent penetration rate. The first slip factor, The pore pressure is [value missing].
6. The method for accurate determination of the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling of multiple mechanisms as described in claim 5, characterized in that, The inherent permeability model includes: in, This is the stress sensitivity coefficient. The effective stress coefficient is... For elastic modulus, The internal expansion coefficient is [value missing]. This represents the maximum adsorption deformation of the matrix in the reservoir rock sample. Poisson's ratio, The pressure required to achieve half of the maximum adsorption deformation.
7. The method for accurate determination of the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling of multiple mechanisms as described in claim 6, characterized in that, Based on the stress sensitivity coefficient and the internal expansion coefficient, the ratios between the contribution percentages of the slippage effect, the stress effect, and the adsorption deformation effect are calculated, including: in, Contribution to the slippage effect The proportion of the stress effect The proportion of the adsorption deformation effect. The confining pressure is the aforementioned pressure.
8. The method for accurate determination of the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling of multiple mechanisms as described in claim 7, characterized in that, Also includes: The adsorption deformation effect is mainly controlled by apparent effective stress, and the stress effect is mainly controlled by apparent effective stress. When the value is greater than 0, it is the stage where the stress effect dominates. When the apparent effective stress corresponds to the apparent effective stress coefficient, When the value is less than 0, it is the stage where the adsorption deformation effect is the main control. Calculate the apparent effective stress coefficient include: 。 9. The method for accurate determination of the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling of multiple mechanisms as described in claim 8, characterized in that, When the contribution ratio of the slippage effect and the contribution ratio of the adsorption deformation effect are equal, the corresponding pore pressure is taken as the critical pressure. If the current pore pressure is greater than the critical pressure, it is the adsorption deformation control stage. If the current pore pressure is less than the critical pressure, it is the slippage effect control stage.
10. A system for accurately determining the effective stress coefficient of permeability in deep unconventional tight reservoirs and decoupling multiple mechanisms, characterized in that, include: An apparent permeability acquisition module is used to introduce non-adsorbed gas and adsorbed gas into reservoir rock samples respectively, and to acquire the first apparent permeability of the non-adsorbed gas and the second apparent permeability of the adsorbed gas under multiple combinations of confining pressure and pore pressure. The region division module is used to identify the permeability rebound boundary based on the first apparent permeability by modeling the continuous evolution surface of permeability, and to divide the pressure space formed by the confining pressure and the pore pressure into the slip effect control zone and the effective stress control zone. The inversion module is used to invert the effective stress coefficient and the first slip factor based on the first apparent permeability within the slip effect control region; to invert the stress sensitivity coefficient of the adsorbed gas based on the effective stress coefficient and the second apparent permeability within the effective stress control region; and to calculate the inherent permeability of the adsorbed gas based on the first slip factor and the second apparent permeability. The model setting module is used to set the inherent permeability model and, based on the inherent permeability of the adsorbed gas, the stress sensitivity coefficient, and the effective stress coefficient, to inversely calculate the internal expansion coefficient. The stage division module is used to calculate the ratio between the contribution ratio of slippage effect, the contribution ratio of stress effect, and the contribution ratio of adsorption deformation effect based on the stress sensitivity coefficient and the internal expansion coefficient, thereby dividing the main control stage of the reservoir extraction cycle.