克拉玛依油田七东1区砾岩油藏泥质含量测井解释方法

Log Interpretation Method of Shale Content for Conglomerate Reservoir,No.1 Area of East 7th Block in Karamay Oilfield

以克拉玛依油田七东1区克下组砾岩油藏为研究对象,结合密闭取心数据和测井曲线资料,分析了不同测井曲线对泥质的响应特征,明确了泥质含量计算的曲线组合,优选密度和中子2条曲线作为泥质含量计算的敏感参数,研究发现砾岩油藏泥质含量与2条曲线的径向幅度差相关性比较好,相对于声波和电法测井,其受岩性及非均质性的影响相对较小,对泥质含量的指示作用更强。为消除2条曲线的物理意义,对其进行归一化处理,重构泥质含量拟合参数(Nsh),即归一化后的幅度差,分3个区域分别建立泥质含量的计算模型。该方法在实际测井解释中精度达到90%以上,取得了较好的应用效果。考虑到泥质对储层孔隙结构及渗透性的影响,建立了泥质含量约束下的渗透率模型,相对于只考虑有效孔隙度影响的单因素线性回归模型,其计算精度大幅提高,为聚驱方案的顺利实施提供了技术支撑。

The conglomerate reservoir of lower Karamay Group in No.1Area of East 7th Block in Karamay Oilfield is selected as the research object,the shale response characteristics of different well logging curves are analyzed combined with sealed core data and well logging curves,and determine the curve combination of shale content calculation,which two well logging curves such as compensation density and neutron porosity are optimized as sensitive parameter to calculate shale content.The research results show that the shale content of conglomerate reservoir has better correlation with the radial amplitude difference of two well logging curves.Compared with acoustic time and electric well logging,it can better reflect the shale content because their influence on lithology and heterogeneity is relatively small.In order to eliminate the physical significance of two well logging curves,the normalization method is used to deal with them and reconstruct shale content fitting parameter Nsh,namely the normalized amplitude difference of two well logging curves.Then the calculation models of shale content are established respectively for three geological regions,the well logging interpretation accuracy is above 90% and gets goodapplication effect.In addition,with shale influence on reservoir pore structure and permeability,the permeability models which is constrained by shale content are established.Compared with the single factor model which just only consider effective porosity influence,the calculation accuracy is greatly improved and provideds technical support for the smooth implementation of polymer flooding project.