1. Guangzhou Marine Geological Survey, Guangzhou, Guangdong 510760, China;
2. CNPC Key Laboratory of Geophysical Exploration, China University of Petroleum (Beijing), Beijing 102249, China;
3. Changqing Division of China Well Logging Compuny, CNPC, Xian, Shaanxi 710201, China
Abstract：Gas hydrate-bearing deposit usually has obvious features on seismic reflection.For example,bottom simulating reflector(BSR) is commonly used as gas hydrate direct indication,but this reflection characteristic does not always mean the presence of gas hydrate.So the background of BSR phenomenon is the base of researches.In this paper,we first analyze three microscopic models of gas hydrate-bearing sedimentary deposit.According to the petrophysical model,we study the variation rule of elastic parameters.Then we discuss the AVA character for the saturation variation based on accurate zoepprize function.At last,we simulate BSR phenomenon using different theoretical model,and at the same time we analyze three external conditions for BSR,and study the tuning effect of gas hydrate-bearing sedimentary deposit.The research result indicates that gas hydrate saturation,free gas and sedimentary deposit's porosity are the important factors for BSR character.So this paper could provide some conclusions for further research of gas hydrate.
