川西天府气田低渗透砂岩储层饱和度计算方法  

A computing method for the water saturation in low-permeability sandstone reservoirs,Tianfu gasfield,western Sichuan Basin

作　　者：夏小勇 谢冰 赖强 韩冰 唐吉锐 刘海军 朱绍武 王跃祥 XIA Xiaoyong;XIE Bing;LAI Qiang;HAN Bing;TANG Jirui;LIU Haijun;ZHU Shaowu;WANG Yuexiang(Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China;Southwest Company,China National Logging Corporation,Chongqing 400021,China)

机构地区：[1]中国石油西南油气田公司勘探开发研究院,四川成都610041 [2]中国石油集团测井有限公司西南分公司,重庆400021

出　　处：《天然气勘探与开发》2025年第1期20-29,共10页Natural Gas Exploration and Development

基　　金：中国石油天然气股份有限公司重大科技专项(编号:2023ZZ25YJ01)。

摘　　要：川西地区天府气田上三叠统须家河组四段气藏是四川盆地致密气下一步产能接替的重要领域,是典型的低渗透储层,岩性、孔隙结构复杂,导致储层孔渗关系和岩电关系常出现“非线性”和“非阿尔奇”现象,给储层饱和度等测井参数精细计算和气水识别带来不小的困难。为了准确计算储层含水饱和度,采用岩石物理实验并引入中间变量导电孔隙度,建立高精度胶结指数的计算模型,确定变m的含水饱和度模型,再与阵列声波弹性参数直接计算的含水饱和度进行对比。研究结果表明:(1)m值、有效孔隙度和导电孔隙度的差值具有较高的相关性,引入中间变量导电孔隙度,构建高精度的变m含水饱和度计算模型,较常规饱和度模型计算精度明显提高;(2)通过阵列声波测井计算含水饱和度,并设计不同饱和度情况下弹性参数变化实验,建立阵列声波弹性参数计算含水饱和度的方法在钙质夹层发育段计算值偏大。结论认为,变m饱和度模型计算的饱和度与密闭取心饱和度相关性较好,能够满足储层评价的需要。As a major domain for the coming productivity replacement of tight gas in Sichuan Basin,the gas reservoirs of the Upper Triassic Xujiahe 4 Member in Tianfu gasfield are typical low-permeability ones with complex lithology and pore structure.There often exists nonlinear relation in porosity and permeability as well as non-Archie rock-electro relation,creating great challenges in computing logging parameters(e.g.water saturation)and identifying gas or water.Thus,introduced the conductive porosity as an intermediate variable,a high-precision computing model of cementation index was established through petrophysical experiments in order for accurate water-saturation computation.And with the variable m value,another model for this computation was confirmed.The obtained saturation was compared with that measured directly from array acoustic elastic parameters.Results show that(i)the variable m value is thoroughly correlated to the difference between effective porosity and conductive porosity.And the confirmed model with the variable m value may achieve more accurate saturation than that from conventional models;and(ii)the established method for computing the water saturation induced from array acoustic elastic parameters,which array acoustic logging data is used for saturation computation and many experiments on elastic parameters are conducted under different water saturation,may yield the overestimated saturation especially in some calcareous interlayer.In conclusion,the water saturation achieved from the model with the variable m value is correlated to that from sealed coring,satisfying the need of reservoir evaluation.

关 键 词：四川盆地西部 天府气田 上三叠统须家河组 低渗透储层 弹性参数 导电孔隙度 变m饱和度模型 

分 类 号：P618.13[天文地球—矿床学]