Xucheng Li
PetroChina Southwest Oil & Gasfield Company, Chengdu 610041, P. R. China

Jing Liang
PetroChina Southwest Oil & Gasfield Company, Chengdu 610041, P. R. China

Weichong Xu
State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, P. R. China

Xiaoping Li
State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, P. R. China

Xiaohua Tan
State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, P. R. China