Experimental Study On Interlayered Crossflow Of Multilayered CBM Reservoir In Eastern Yunnan And Western Guizhou

Coalbed methane(CBM),as an important carrier to promote energy production and consumption revolution in China,has been largely developed in Qinshui Basin and Ordos Basin.The resources in eastern Yunnan and western Guizhou are abundant and in urgent need of exploitation.It is necessary to adopt commingling production for the CBM in this region,where has the characteristics of multilayer and thin coal seams,low permeability and high crustal stress.However,in the development process,it is difficult to accurately predict the commingling production due to crossflow between different coal seams and sandstone interlayer.Therefore,this paper focuses on the research of interlayer crossflow in multiple CBM reservoir.(1)Based on the experimental apparatus of commingled production in multilayered CBM reservoir by the lab,a set of experimental procedure is presented,and the crossflow experiment of CBM reservoirs was carried out.Factors such as axial pressure,the horizontal effective stress,interlayer pore pressure difference and e permeability of sandstone are analyzed based on the exerpimental results.(2)Based on dimensionless analysis and a semi-empirical and semi-theoretical model of interlayer crossflow in CBM is established.And the empirical formula of interlayer crossflow in CBM is established by linear regression method,which based on the experimental data of interlayer crossflow in CBM.Its can predict interlayer crossflow flow under different axial pressure,horizontal effective stress,interlayer pore pressure and interlayer permeability.