Propagation of pressure drop in coalbed methane reservoir during drainage stage

• DOI: 10.26804/ager.2019.04.06
• Publication Date: 2020-01-08T02:44:02Z
• Authors: Ding Jia; Yongkai Qiu; Chong Li; Yidong Cai
• Keywords: Coalbed Methane; Funnel

Numerical simulation was employed to investigate the propagation speed of pressure drop at drainage stage in coalbed methane (CBM) reservoirs. A seepage model single-phase water CBM reservoirs generated with parameter from well ZS39 Zhengzhuang block southern Qinshui Basin. The effects stress sensitivity and reservoir properties on process were analysed. Moreover funnel scale index introduced quantitatively characterize process. results indicate that cause permeability form funnel, which is consistent shape funnel. Under constant bottom pressure, will gradually decrease both longitudinal lateral direction. And overall rapidly increases first then decreases. In scenario steady bottomhole shows an increasing trend direction, a decreasing all along. positively correlated initial porosity, elastic modulus. For Poisson ratio, when ratio small, has negative correlation. As over 0.35, positive correlation exists. It found analysis petrophysical parameters have strong drop, especially for permeability. Therefore, this work may provide insights into properties, thus be favorable improving recovery. Cited as : Jia, D., Qiu, Y., Li, C, Cai, Y. Propagation during stage. Advances Geo-Energy Research, 2019, 3(4): 387-395, doi: 10.26804/ager.2019.04.06