Exploration and Practice of Methane-Leading Reservoir Stimulation Technology of High-Rank Coalbed Methane

Abstract

In order to solve the problems of poor adaptability of reservoir stimulation technology and low gas production of single well in high-rank coalbed methane (CBM) reservoir, a new concept of "methane-leading" reservoir stimulation technology and the corresponding technology method system are put forward. The concept of "methane-leading" reservoir stimulation technology emphasizes the complexity of the coal reservoir and the energy releasing process in the coalbed methane development. Through targeted artificial stimulation, a multi-stage interconnected fracture network system is built to reduce seepage resistance and finally improve the gas production of single well. The characteristics of coal reservoir and problems of traditional stimulation technology are analyzed in this paper. And the "methane-leading" reservoir stimulation technology focus on the optimization of the "sweet section", the release of injected energy and the expansion of area stimulated by the fracture network. The application results in the CBM field in the south of Qinshui basin, Shanxi Province, China, shows that the gas production of a single vertical well is more than twice that of an old well in the same area, reaching 2500~3000 m3/d and the average gas production per horizontal well is over 10000 m3/d, indicating a good application prospect. The innovation of this paper lies in that a new concept of "methane-leading" reservoir stimulation technology and the corresponding technology method with CBM characteristics are put forward. It provides new ideas and methods for effectively improving the gas production capacity of CBM single well, realizing efficient development of high-rank CBM and promoting the healthy development of CBM industry.