基于水合物指示因子的地震识别方法  

Hydrate identification based on hydrate indicator

作　　者：邓炜 梁金强[1,3] 钟桐 何玉林 孟苗苗 DENG Wei;LIANG Jin-Qiang;ZHONG Tong;HE Yu-Lin;MENG Miao-Miao(Guangzhou Marine Geological Survey,CGS,Guangzhou 510075,China;Key Laboratory of Marine Mineral Resources,Guangzhou Marine Geological Survey,Guangzhou 510075,China;Natural Gas Hydrate Engineering Technology Center,CGS,Guangzhou 510700,China)

机构地区：[1]中国地质调查局广州海洋地质调查局,广东广州510075 [2]自然资源部海底矿产资源重点实验室,广东广州510075 [3]中国地质调查局天然气水合物工程技术中心,广东广州510700

出　　处：《物探与化探》2021年第1期57-67,共11页Geophysical and Geochemical Exploration

基　　金：中国地质调查局地质调查项目“南海北部天然气水合物重点区资源调查”(DD20190217);自然资源部海底矿产资源重点实验室开放基金“基于温压控制建模的水合物指示因子直接反演”(KLMMR-2018-A-04)。

摘　　要：速度是水合物勘查的重要参数,但是速度的影响因素众多,给高精度识别水合物带来一定困难。水合物储层岩石物理是研究多种因素对速度影响的有效手段之一。考虑到水合物储层未固结等特征,本文采用SCA-DEM模型,重点对比了孔隙度、饱和度等对纵横波速度以及AVO特征的影响,并构建了一种新的水合物指示因子,消除了由于孔隙变化带来的假异常。岩石物理分析表明该指示因子与水合物饱和度具有很高的相关性。然后,推导得到了基于水合物指示因子的地震反射特征方程,并基于该方程反演得到了水合物指示因子,反演结果与实际钻探结果吻合较好,表明该方法具有一定的实用性以及科学性。Compared with the post-stack inversion,coupling features in impedance are complex.The pre-stack inversion can make full use of the information such as the amplitude and travel time and frequency of the prestack seismic data,more diverse logging data and geology,and yields geophysical parameters that are highly correlated with hydrate saturation.Seismic rock physics modeling of hydrate reservoirs is the basis for hydrate-oriented prestack inversion.Considering the microscopic pore structure and composition characteristics of hydrate reservoir rocks,this paper introduces SCA-DEM rock physics modeling methods.The influence of physicochemical parameters on the elastic characteristics of rock and its role in AVO characteristics are analyzed.The geophysical response of hydrates is discussed and a new hydrate seismic indicator is constructed.Seismic rock physics analysis shows that the indicator has a high correlation with hydrate saturation.Then,the seismic reflection equation based on hydrate indicator is derived and the feasibility analysis of the inversion is carried out.Finally,based on geological prior,we get the indicator using the actual pre-stack data and logging data in the Qiongdongnan sea of South China Sea.The real data application shows that the method has certain practicability and scientificity.

关 键 词：水合物指示因子 岩石物理 叠前反演 琼东南 

分 类 号：P631.4[天文地球—地质矿产勘探]