CN-121980855-A - Analysis method for deep resource fluidization exploitation rock mass breaking mechanism

CN121980855ACN 121980855 ACN121980855 ACN 121980855ACN-121980855-A

Abstract

The invention discloses a method for analyzing a rock mass breaking mechanism in deep resource fluidization exploitation, and belongs to the technical field of deep resource exploitation. The method comprises the steps of obtaining and preprocessing deep resource fluidization exploitation basic parameters, constructing a heterogeneous mechanical parameter field and a discrete fracture network model, establishing a three-dimensional geological model based on obtained geological environment data and engineering disturbance parameter sets, coupling a seepage field and a stress field, dynamically iterating to obtain a time sequence stress field, introducing a correlation coefficient and a correlation factor to construct a criterion expansion criterion set, and accordingly introducing the heterogeneous mechanical parameter field, the discrete fracture network model, the time sequence stress field and the criterion expansion criterion set into a coupling numerical model and simulating a rock mass fracture process to obtain a rock mass fracture expansion path. The method realizes dynamic and accurate prediction of rock mass fracture, provides support for optimization of deep resource fluidization exploitation parameters and definition of safety boundaries, ensures efficient development of mineral resources and reduces engineering risks.

Inventors

LI CUNBAO
HU JIANJUN
XIE HEPING

Assignees

深圳大学

Dates

Publication Date: 20260505
Application Date: 20260113

Claims (8)

1. The analysis method of the deep resource fluidization mining rock mass breaking mechanism is characterized by comprising the following steps of: s1, acquiring deep resource fluidization exploitation basic parameters and geological environment data, and performing data preprocessing on the deep resource fluidization exploitation basic parameters to obtain a rock mass parameter distribution field and an engineering disturbance parameter set; s2, constructing a heterogeneous mechanical parameter field based on a rock parameter distribution field by adopting a random medium theory and fractal geometry, and generating a discrete fracture network model by combining Monte Carlo simulation; s3, constructing a three-dimensional geological model based on geological environment data and engineering disturbance parameter sets, coupling the seepage field and the stress field, and dynamically and iteratively calculating and outputting a time sequence stress field according to a mining time sequence; S4, based on a heterogeneous mechanical parameter field, a time sequence stress field and an engineering disturbance parameter set, introducing a heterogeneous correction coefficient and an engineering disturbance coefficient to construct a fracture starting criterion, and introducing a heterogeneous guiding factor and a disturbance stress direction factor to construct a fracture expansion criterion to form a criterion expansion criterion set; S5, introducing the heterogeneous mechanical parameter field, the discrete fracture network model, the time sequence stress field and the criterion expansion criterion set into the coupling numerical model and simulating the rock mass cracking process to obtain a rock mass cracking expansion path.
2. A method of analyzing a fracture mechanism of a deep resource fluidization exploitation rock according to claim 1, wherein the deep resource fluidization exploitation base parameters comprise a rock physical mechanical parameter and an engineering disturbance parameter, the engineering disturbance parameter comprises a exploitation equipment vibration frequency, a exploitation equipment vibration amplitude, a resource exploitation rate, support data and a wellbore parameter, the rock physical mechanical parameter comprises an elastic modulus, a compressive strength, a tensile strength and fracture observation data, and the fracture observation data comprises at least a fracture linear density, a fracture strike, a fracture dip, a fracture length and a fracture width.
3. The analysis method for deep resource fluidization exploitation rock burst mechanism according to claim 2, wherein the data preprocessing process is as follows: Removing abnormal values of physical and mechanical parameters of the rock mass by adopting a3 sigma criterion in sequence, carrying out data standardization by adopting a Z-score method, and carrying out space continuous reconstruction by adopting a kriging interpolation to generate a rock mass parameter distribution field; and classifying and sorting the engineering disturbance parameters into a structured engineering disturbance parameter set according to the process parameters and the arrangement parameters.
4. A deep resource fluidization mining rock mass breaking mechanism analysis method as recited in claim 3, wherein the process of constructing the heterogeneous mechanical parameter field is as follows: Extracting physical property parameters in a rock mass parameter distribution field, and selecting a distribution type with optimal suitability of the physical property parameters as a spatial distribution model of the distribution type by K-S test under the assumption that the physical property parameters are subjected to any one of logarithmic normal distribution and Weibull distribution; Calculating fractal dimension of physical property parameters by adopting a box dimension method, constructing likelihood functions of the physical property parameters by using a maximum likelihood estimation method based on a spatial distribution model, and solving the likelihood functions to obtain distribution parameters; Based on a random medium theory, taking a distribution parameter and a fractal dimension as input, combining a preset depth resource three-dimensional mining geological boundary, and carrying out fractal interpolation and random simulation coupling through a programming tool to obtain a heterogeneous mechanical parameter field, wherein each grid unit in the heterogeneous mechanical parameter field is endowed with a corresponding physical property parameter.
5. The analysis method of deep resource fluidization exploitation rock burst mechanism according to claim 4, wherein the generation process of the discrete fracture network model is as follows: Extracting fracture observation data in a rock mass parameter distribution field, respectively determining probability distribution types of each parameter in the fracture observation data through statistical analysis, and solving parameter distribution characteristics of each parameter by adopting a maximum likelihood estimation method according to the probability distribution types; Based on the parameter distribution characteristics of each parameter, generating a plurality of fracture foundation units through Monte Carlo simulation random sampling, wherein the fracture foundation units all carry fracture observation data and are all positioned in a preset depth resource three-dimensional mining geological boundary; introducing all the crack foundation units into a three-dimensional space coordinate system, determining the space attitude of each crack foundation unit according to the crack trend and the crack inclination angle, simultaneously calculating the overlapping degree of each crack foundation unit, removing redundant crack foundation units with the overlapping degree exceeding 80%, and constructing an initial three-dimensional crack set; Classifying the crack foundation units in the initial three-dimensional crack set, dividing the crack foundation units with the crack length being more than or equal to 5m and the crack width being more than or equal to 2mm into dominant cracks, dividing the crack foundation units with the crack length being less than 5m or the crack width being less than 2mm into secondary cracks, and adding corresponding crack labels; and embedding all the fracture basic units added with the fracture labels into corresponding spatial positions in the heterogeneous mechanical parameter field to form a discrete fracture network model.
6. The analysis method for deep resource fluidization exploitation rock burst mechanism according to claim 5, wherein the construction process of the three-dimensional geological model is as follows: And constructing a three-dimensional geological model comprising rock stratum, fault and aquifer by taking a preset depth resource three-dimensional exploitation geological boundary as a spatial range and taking geological environment data as input through three-dimensional geological modeling software.
7. The analysis method for deep resource fluidization exploitation rock mass breaking mechanism according to claim 6, wherein the method for time sequence dynamic iterative calculation is as follows: S31, dividing the deep resource exploitation time length into a plurality of equal-time-interval calculation steps according to the deep resource exploitation period requirement; s32, establishing a seepage control equation based on a three-dimensional geological model through Darcy's law, and solving by adopting a finite element method to obtain the global seepage field distribution of the calculation step; S33, superposing the global seepage field distribution and the engineering disturbance parameter set by taking the geometric boundary of the three-dimensional geological model as constraint, and solving the stress field of the calculation step through an elastic mechanical balance equation; s34, correcting the rock mass permeability through cube law according to the opening and closing degree change of the crack under the stress field of the calculation step, feeding the corrected rock mass permeability back to a seepage control equation, repeating S32-S3 until the maximum change rate of the stress field of the calculation step is less than or equal to 5%, and outputting stress data of the calculation step; S35, carrying out S32-S34 on all calculation steps to obtain stress data of each calculation step, and forming a time sequence stress field according to the stress data.
8. The analysis method of deep resource fluidization exploitation rock mass breaking mechanism according to claim 7, wherein the coupling numerical model is a FEM and DEM coupling model; the steps of the simulated rock mass breaking process are as follows: Importing a heterogeneous mechanical parameter field, a discrete fracture network model, a three-dimensional geological model and a criterion expansion criterion set into a coupling numerical model and completing initialization, wherein FEM calculates macroscopic stress data, and DEM simulates fracture evolution; According to synchronous iteration of mining time sequence, the FEM transmits macroscopic stress data to the DEM, the DEM checks the fracture states of the dominant fracture and the secondary fracture in simulated fracture evolution based on a criterion expansion criterion set, generates a new fracture or updates the fracture morphology and corrects physical property parameters, and feeds back to the FEM until no new fracture is generated or the preset mining time length is reached, and a rock fracture expansion path containing fracture space coordinates and time sequence evolution information is output.

Description

Analysis method for deep resource fluidization exploitation rock mass breaking mechanism Technical Field The invention relates to the technical field of deep resource exploitation, in particular to a method for analyzing a deep resource fluidization exploitation rock mass breaking mechanism. Background With the continuous increase of global energy demand, the development and utilization of deep resources have become a key direction for guaranteeing energy safety. The fluidization exploitation technology belongs to a future exploration technology, and is characterized in that solid mineral resources are exploited after being converted into gas or liquid, and the rock mass breaking process is ascertained in the process, so that the technology is an important guarantee for realizing safe and efficient exploitation of the resources. However, the deep rock mass is in a high-temperature, high-pressure and high-stress complex geological environment, and the rock mass has strong heterogeneous and crack development characteristics, so that the complexity of a rock mass cracking mechanism is further increased, and if a cracking evolution rule cannot be accurately analyzed, the problems of stratum instability, low resource recovery rate, engineering safety accidents and the like are easily caused, so that the large-scale application of the deep resource fluidization exploitation technology is restricted. Currently, a certain research progress has been made in rock mass fracture mechanism analysis methods. As disclosed in patent application publication number CN118818602a, a rock breaking mechanism analysis method based on dual main frequency characteristics of microseismic signals is disclosed, the method extracts the high and low main frequency characteristics of microseismic signals through fast fourier transform, and combines a parameter analysis method and a polarity mean method to establish the association relationship between the dual main frequency characteristics and tension breaking and shear breaking, thereby realizing the identification of rock breaking mechanisms with different scales. The method has the characteristics of high accuracy and good universality in the aspect of discriminating the fracture type, and provides an important monitoring analysis idea for researching the rock fracture mechanism. However, in the deep resource fluidization exploitation scene, the prior art still has obvious defects that firstly, the prior analysis method is used for carrying out post-identification by depending on microseismic signal monitoring results, dynamic simulation capability of a fracturing process is lacked, key factors such as the heterogeneity, geological structure and the like of a rock mass are difficult to combine, the forward looking prediction of fracture starting and expanding paths is realized, secondly, in the deep fluidization exploitation, dynamic coupling of a seepage field and a stress field is a core factor for driving the rock mass to fracture, the time sequence evolution characteristic of the coupling effect is not fully considered, the fracture criterion is not optimized according to the grading characteristics of dominant fractures and secondary fractures in the rock mass, so that deviation exists between the analysis result and an engineering actual scene, thirdly, the patent CN118818602A focuses on type discrimination of a fracturing mechanism, but three-dimensional space characterization and time evolution rule quantification of the fracturing expanding paths are not involved, and direct technical support cannot be provided for optimizing the deep resource fluidization exploitation parameters and defining safety boundaries in the fluidization exploitation. Therefore, aiming at the special requirements of deep resource fluidization exploitation, an analysis method capable of coupling rock mass heterogeneity, engineering disturbance and seepage stress dynamic evolution and integrating rupture mechanism identification and expansion path simulation is needed to solve the problems of insufficient dynamic predictability, poor suitability and weak engineering guidance in the prior art, and provide technical support for safe and efficient implementation of deep resource fluidization exploitation. Disclosure of Invention The invention aims to provide a method for analyzing a breaking mechanism of deep resource fluidization exploitation rock mass, so as to solve the problems in the background technology. In order to achieve the above object, the present invention provides the following technical solutions: The analysis method of the deep resource fluidization mining rock mass breaking mechanism comprises the following steps: s1, acquiring deep resource fluidization exploitation basic parameters and geological environment data, and performing data preprocessing on the deep resource fluidization exploitation basic parameters to obtain a rock mass parameter distribution field and an engineering distu