1. Unconventional Petroleum Research Institute, China University of Petroleum, Bejing, Beijing 102-249, China
2. Center for Engineering, Research into Artifacts (RACE), The University of Tokyo, Chiba 277-8568, Japan
3. Instituto de Física, Universidade de São Paulo, CP 66318, São Paulo, SP 05315-970, Brazil
4. Fukada Geological Institute, Tokyo 113-0021, Japan