Coal-bed methane reservoirs are characterized by low porosity

low permeability and low pressure

making their industrial exploitation primarily reliant on techniques like hydraulic fracturing. Currently

more than 50 percent of the gas wells in the Shizhuang block in the Qinshui Basin currently produce less than 500 m

3

/d of coal bed methane. However

the increase in production after gas well retrofitting has not been ideal and the main factors affecting gas well productivity remain unclear

directly impacting the overall improvement. To address this

the degree of influence of geological and engineering factors on fracturing productivity

in coal-bed gas wells is described using the gray correlation method

and the main factors controlling gas well productivity after fracturing are analyzed. A correlation mathematical model between the main control factors and gas well production is established using the Pearson correlation analysis method to predict gas well productivity. The reliability of the prediction model is verified through gas well data validation. Furthermore

a classification decision tree is established using the chi-square automatic interactive detection decision tree method

in conjunction with gas well productivity data

to understand the impact of geological and engineering factors on gas well productivity in fractured wells. Under high gas content conditions

engineering factors have a relatively small impact on the productivity improvement of gas wells. However

as the gas content decreases

the impact of different engineering factors on the gas well productivity gradually increases

which helps optimize the main design parameters such as displacement

sand volume

and total liquid volume

enriching the evaluation methods for post fracturing productivity of coal seam pressure.