基于电阻率测井的天然气水合物饱和度估算及估算精度分析  

Estimation of Gas Hydrate Saturation Based on Resistivity Logging and Analysis of Estimation Error

作　　者：王秀娟[1] 吴时国[1] 刘学伟[2] 郭依群[3] 陆敬安[3] 杨胜雄[3] 梁金强[3] 

机构地区：[1]中国科学院海洋研究所中国科学院海洋地质与环境重点实验室,山东青岛266071 [2]中国地质大学地球物理与信息技术学院,北京100083 [3]广州海洋地质调查局,广东广州510760

出　　处：《现代地质》2010年第5期993-999,共7页Geoscience

基　　金：中国科学院重要方向性项目(KZCX2-YW-229);国家自然科学基金项目(40706026);国际科技合作项目(2010DFA21740);国家科技重大专项项目(2008ZX05026-004-08)

摘　　要：利用电阻率测井基于阿尔奇公式能够估算孔隙空间中天然气水合物饱和度。基于神狐海域的水合物钻井(SH2站位)资料,利用密度反演的地层孔隙度与地层因子交会图,计算出估算水合物饱和度的阿尔奇常数。假定地层中水合物呈均匀分布,利用电阻率资料计算的该站位水合物饱和度平均为24%,最高达44%,水合物饱和度在垂向上具有明显的不均匀性;利用孔隙水氯离子异常估算的SH2站位水合物饱和度平均值为25%,最高值达48%,厚度为25 m。这两种方法估算的水合物饱和度基本吻合,利用电阻率资料计算的饱和度与阿尔奇常数和饱和度指数及孔隙度有关。Gas hydrate saturations can be estimated from the Archie equation and the estimation error is dependent on the porosity,saturation factor and Archie＇s parameters.From the crossplot between density porosity and formation factor of site SH2 in Shenhu area,the Archie parameters were calculated based on the water-saturated sediments.Gas hydrate saturation estimated from isotropic resistivity has an average value of 24% with a maximum value of 44%.The distribution of gas hydrate is heterogeneous in vertical.Chloride anomalies in the core samples show that the average saturation is about 25% in the pore space with a maximum value of 48%,and the thickness of gas hydrate is about 25 meters.The results show that gas hydrate saturations estimated from resistivity data by using the environment parameters in Shenhua area are similar to those estimated from chloride anomalies.The value of gas hydrate saturation estimated from resistivity data depends on the parameters of Archie parameters and the gas hydrate exponents.

关 键 词：天然气水合物 电阻率 饱和度 不均匀性 神狐海域 

分 类 号：P631.8[天文地球—地质矿产勘探] TE122.2[天文地球—地质学]