南海神狐海域天然气水合物储层参数测井评价  

Gas hydrate reservoir parameter evaluation using logging data in the Shenhu area,South China Sea

作　　者：刘洁[1] 张建中[1,2] 孙运宝 赵铁虎[2,3] 

机构地区：[1]海底科学与探测技术教育部重点实验室中国海洋大学海洋地球科学学院,山东青岛266100 [2]海洋国家实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266061 [3]中国地质调查局青岛海洋地质研究所,山东青岛266071

出　　处：《天然气地球科学》2017年第1期164-172,共9页Natural Gas Geoscience

基　　金：中国地质调查局国家海洋地质专项工作项目(编号:GZH201100308);国家自然科学基金项目(编号:41230318;41074077)联合资助

摘　　要：南海北部神狐海域经历了复杂的构造演化过程,断裂发育,该区天然气水合物的垂向分布具有明显的不连续性和不均匀性。利用测井资料计算地层孔隙度和水合物储层饱和度等参数,对深入研究储层水合物分布特征、储层优选等具有重要意义。基于电阻率和声波测井等资料,讨论了地层孔隙度的几种计算和修正方法,并在此基础上对南海神狐海域SH2井水合物饱和度做了探讨和定量评价。结果表明:考虑泥质含量和井径变化等因素的影响,要对密度法计算的孔隙度进行适当修正;含泥质修正的电阻率法能较准确地预测水合物饱和度;不同的岩石物理模型影响饱和度的计算结果,四相介质Wood方程和等效介质理论各有优势和不足,将上述2个模型结合得到改进的Wood方程计算的水合物饱和度与通过氯离子浓度异常计算的饱和度值吻合较好。多种评价方法结果相一致可表明水合物的大致分布,由此估计沿SH2井饱和度大于20%的水合物层厚度约为22m,最大含量约为23%。The Shenhu area, northern South China Sea, has experienced a complex tectonic evolution process, full of faults, and the vertical distribution of gas hydrate zone is obviously discontinuous and une- ven.Estimating formation porosity and hydrate reservoir saturation and other parameters using logging da- ta has great significance for further study of reservoir distribution characteristics and selection of high qual- ity reservoir.Based on resistivity and sonic logging data, several estimation and correction methods of po- rosity were discussed.Then,gas hydrate saturation of Well SH2 in the Shenhu area of South China Sea was studied and evaluated quantitatively.It is shown that when considering the effect of clay content and hole diameter change, the porosity estimated by density method should be corrected appropriately, and the mud- modified resistivity method can more accurately describe the hydrate saturation. Besides, the selection of rock-physics models in velocity method is one of the most important factors affecting the inversion satura- tion.Four-phase Wood equation and effective medium theory have certain advantages and deficiencies,and a modified Wood equation is got by the combination of above two models.The hydrate saturation calculated by the modified Wood equation is well consistent with the estimated results by chloride ion concentration anomaly.The consistent results of different evaluation methods indicate the general distribution of gas hy- drate,and it is estimated that the thickness of layer along Well SH2 where hydrate saturation is greater than 20% is about 22m,and the maximum concentration is about 23%.

关 键 词：天然气水合物 孔隙度 饱和度 电阻率 岩石物理模型 神狐海域 

分 类 号：TE373[石油与天然气工程—油气田开发工程]