Numerical Simulation Study On Modern Tectonic Stress Of Wushenqi Coalfield

As an important support for the industrial development of a country,energy has an important impact on the overall development of the country.China has been in the situation of rich coal,poor oil and little gas for a long time,and a large number of oil and gas resources need to be imported.After the shale gas revolution in the United States,its domestic energy has achieved basic self-sufficiency,which has aroused the enthusiasm of the world for the research and development of unconventional natural gas(shale gas,coalbed methane,etc.).The development and research of unconventional natural gas in China is hindered by complex geological environment,so it is difficult to achieve large-scale production.Therefore,through the research and prediction of complex geological conditions in the process of CBM development,this paper can guide the CBM drilling work in Wushenqi area,improve the output of CBM mining,and improve the economic value of CBM mining.In order to find out the characteristics of modern tectonic stress field in Wushenqi area,this paper uses PGTS,a numerical simulation software developed based on the finite element method,and uses the elastic-plastic incremental method to study the modern tectonic stress field in Wushenqi area.Firstly,the geological base map of the area is described by Doublefox software,and the geological model of the area is established;secondly,the mathematical model is established by unit division,node sorting and other operations of the geological model;finally,the stress boundary points are manually leveled after sorting,and then the gulunels file is established and imported into the numerical simulation software to complete the simulation calculation.The stress direction file and the difference stress value file are obtained by calculation.Through the image processing of double foxes,a more intuitive stress characteristic map(including the stress direction and the difference stress contour map)is obtained.Through the analysis and prediction of the map,look for the favorable area of coalbed methane exploitation.Based on the study of the modern tectonic stress field in Wushenqi area,the characteristics of the modern tectonic stress field in this area are obtained: the direction of the regional principal stress is about ne 70°,the magnitude of the principal stress is about 62 MPa,and the range of the difference stress is 8?20 MPa.After finding out the characteristics of the tectonic stress field in the study area,combined with the image analysis,it can be concluded that the stress distribution in the northwest and southeast of the study area is uniform,there is no obvious stress concentration area,and the differential stress isolines are relatively dense,which is a favorable area for CBM development.As far as possible,the horizontal well should be drilled in the vertical direction of the maximum principal stress direction,and the area with relatively dense differential stress isolines.In this way,it can promote the distribution of artificial fracture and connect more gas storage units,so as to increase the output of single well of coalbed methane and enhance the economic value of development.The characteristics of the modern tectonic stress field in this area are determined,which provides a reference for the well location selection and horizontal drilling direction selection of CBM surface mining well pattern,as well as a research idea for the research work of CBM drilling exploration and development.