南海神狐海域天然气水合物储层参数测井评价

发布时间：2018-04-03 10:53

本文选题：天然气水合物　切入点：孔隙度　出处：《天然气地球科学》2017年01期

【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%。
[Abstract]:The Shenhu sea area in the northern part of the South China Sea has undergone complicated tectonic evolution and developed faults. The vertical distribution of natural gas hydrate in this area has obvious discontinuity and heterogeneity.Using logging data to calculate the formation porosity and hydrate reservoir saturation is of great significance for the further study of reservoir hydrate distribution characteristics and reservoir selection.Based on the data of resistivity and acoustic logging, several methods for calculating and modifying porosity of formation are discussed, and the hydrate saturation of SH2 well in Shenhu sea area of South China Sea is discussed and quantitatively evaluated.The results show that the porosity calculated by density method should be modified properly considering the influence of mud content and well diameter variation, and the resistivity method with muddy modification can accurately predict hydrate saturation.Different rock physical models affect the calculation results of saturation. The Wood equation of four-phase medium and the theory of equivalent medium have respective advantages and disadvantages.The hydrate saturation calculated by combining the above two models with the modified Wood equation is in good agreement with the saturation calculated by the chloride ion concentration anomaly.The results of various evaluation methods are consistent with each other to indicate the general distribution of hydrate. The thickness of hydrate layer with saturation more than 20% along SH2 well is estimated to be about 22 m and the maximum content is about 23 m.
【作者单位】：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;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;中国地质调查局青岛海洋地质研究所;
【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
【分类号】：P618.13;P631.81

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