Study on gas production and water production characteristics of CBM vertical wells under multi period tectonic movement of un-development fault in central south Qinshui Basin

It is important to reduce the blinding investment on the project and accurately predict the gas production by identifying the gas production characteristics of CBM vertical wells within a small range un-development fault. Through the analysis of the gas production and water production of CBM vertical wells and the main controlling factors at differ- ent tectonic positions in the central and southern Qinshui Basin within a small range,the differences of gas transport and water transport and permeability in coupled stress superposition effects in Yanshan period and Xishan period are found as the essential reason for gas production and water production. The differences of floor elevation resulted in the differences of gas and water transport routes,reservoir pressure gradient and water production. The permeability is the lowest in the uplift or depression blocks of multi-periods fold coupling areas in medium or strong deformation regions. The permeability is the highest in the high values of the floor elevation in weak deformation regions. The differences of reservoir pressure gradient,permeability and gas and water transport route within a small range lead to the differences of gas and water production curves characteristics. These characteristics are as follows:water and gas production are both high,water is high and gas is low,water is low and gas is high,water is low and gas is low.