Seismic fine imaging and its significance for natural gas hydrate exploration in the Shenhu Test Area, South China Sea

作者：Hua Xue,Min Du,Bin Zhao,Bao-jin Zhang,Sheng-xuan Liu,Peng-fei Wen,Bin Liu,Ru-wei Zhang,Yun-xia Xu,Xi Chen

摘要：Shenhu area in South China Sea includes extensive collapse and diapir structures,forming high-angle faults and vertical fracture system,which functions as a fluid migration channel for gas hydrate formation.In order to improve the imaging precision of natural gas hydrate in this area,especially for fault and fracture structures,the present work propose a velocity stitching technique that accelerates effectively the convergence of the shallow seafloor,indicating seafloor horizon interpretation and the initial interval velocity for model building.In the depth domain,pre-stack depth migration and residual curvature are built into the model based on high-precision grid-tomography velocity inversion,after several rounds of tomographic iterations,as the residual velocity field converges gradually.Test results of the Shenhu area show that the imaging precision of the fault zone is obviously improved,the fracture structures appear more clearly,the wave group characteristics significantly change for the better and the signal-to-noise ratio and resolution are improved.These improvements provide the necessary basis for the new reservoir model and field drilling risk tips,help optimize the favorable drilling target,and are crucial for the natural gas resource potential evaluation.

發文機構：Guangzhou Marine Geological Survey Southern Marine Science and Engineering Guangdong Laboratory（Guangzhou）

關鍵詞：NaturalgashydrateFineseismicimagingVelocitystitchingtechniqueHigh-precisiongrid-tomographyvelocityinversionFaultResidualcurvatureanalysisNGHexplorationtrialengineeringSouthChinaSea

分類號： P31[天文地球—固體地球物理學]