1. College of Oceanography, Hohai University 1 , Nanjing 210098, China
2. Laoshan Laboratory 2 , Qingdao 266237, China
3. Key Laboratory of Gas Hydrate, Ministry of Natural Resources, Qingdao Institute of Marine Geology 3 , Qingdao 266237, China
4. Sinopec Research Institute of Petroleum Engineering 4 , Beijing 102206, China