A study of elastic least-squares reverse time migration for gas hydrate reservoirs
LI Jin-Li1, 2, QU Ying-Ming3, LIU Jian-Xun1, 2, YUE Hang-Yyu1, 2, LI Pei1, 2, CHEN De-Yuan1, 2
1.National Modern Geological Exploration Technology Research Center,Langfang 065000,China; 2.Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang 065000,China; 3.School of Geosciences,China University of Petroleum (East China),Qingdao 266580,China
Abstract:The elastic properties of gas hydrate are obviously different from those of the surrounding rocks.The traditional acoustic imaging method using acoustic approximation cannot accurately describe the elastic properties.The imaging results of elastic wave migration method have low resolution,weak energy in deep regions,imbalance amplitude, low frequency noise and acquisition footprint.For this reason,the authors have developed an elastic least-squares inverse time migration method.In this method,an accurate migration operator and demigration operator in the framework of the elastic least squares theory are derived.To improve the computation efficiency and save memory,the authors introduced the multisource elastic least-squares migration method based on encoding technique,in which multiple data are added into a supershot and the encoding technique is used to suppress the crosstalk.The effectiveness and superiority of the proposed method for gas hydrate reservoir imaging are verified by the simulation results of two gas hydrate models.
李金丽, 曲英铭, 刘建勋, 岳航羽, 李培, 陈德元. 天然气水合物储层弹性波最小二乘逆时偏移研究[J]. 物探与化探, 2017, 41(6): 1050-1059.
LI Jin-Li, QU Ying-Ming, LIU Jian-Xun, YUE Hang-Yyu, LI Pei, CHEN De-Yuan. A study of elastic least-squares reverse time migration for gas hydrate reservoirs. Geophysical and Geochemical Exploration, 2017, 41(6): 1050-1059.
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