Study on Coalbed Methane Well Production Characteristics and Control Factors in Chengzhuang Block

It was precondition and groundwork of the technological selection and parameters optimization of coalbed methane development to find out the control f actors of coalbed methane production characteristics. Based on the data of coalbed methane wells that had been put into production for more than two years,the coalbe d methane well production characteristics and its control factors were analyzed in Chengzhuang Block. Generally,the gas production rate was relatively low in Chengzh uang Block. The relationship between gas and water production was complicated. The types of coalbed methane well production included high gas yield-low water yield, high gas yield-high water yield,low gas yield-low water yield,low gas yield-high water yield and no gas yield-no water yield. The production characteristics were influenc ed by gas saturation,the ratio of critical desorption pressure to reservoir pressure,the tectonic position of wells,fault and collapse column,groundwater dynamics,the frac turing effect,geostress and the drainage ways,and so on.