Mathematical Model Study Of Coal Seam Re-fracturing Well Selection

It must be fractured to realize large-scale production to both low production and cut of production of gas wells.Although the development of coal seam gas is mainly in the stage of primary fracturing,the coal seam gas repeated fracturing is the trend and main in the future.However,the selection of coal seams and the layers are the basis of the repeated fracturing of coal seams,and also the key and difficult problem related to the effect of repeated fracturing of coal seams,and the research is necessary and significant.In this paper,the mathematical model of selecting wells and layers for repeated fracturing of coal seams is researched,and based on the analysis of factors affecting the effect of repeated fracturing of coal seams,the corresponding mathematical model's are established respectively for the case of few and more training samples.Through the research work of master's degree,in this paper,the following results are obtained:(1)Based on the original data preprocessing,reveals the main factors of affecting coal seam re-fracturing effect by analysis and comprehensive application of grey relational analysis,correlation and principal component analysis,and laid the foundation of the mathematical model for selecting the well and layer of the coal seam repeated fracturing.(2)In the case of less training samples,based on the main control factors affecting the effect of repeated fracturing of coal seam are taken,the fuzzy comprehensive evaluation model has been established for the selection of well and layer of coal seams.(3)About the large number of training samples,based on the main control factors affecting the effect of repeated fracturing of coal seams,the probabilistic neural network model has established for selecting wells and layers for repeated fracturing of coal seams,and randomness of parameter values is taken into account.