利用测井资料识别国外L油田流体性质

Identification of foreign L oilfield fluid properties by means of logging data

基于交会图法和岩心资料,分析国外中亚地区L油田的常规测井曲线特征与岩性和流体类型的关系.首先,对测井资料进行整理归纳,消除不同时期测井系列的差异,进行归一化、标准化及其他预处理;然后,以岩心资料为基础,建立测井资料交会图版,利用图版进行岩性和流体识别,其中岩性主要依据自然电位SP、中子伽马NRAT、感应电阻率ILD交会图版识别,流体类型主要依据含水饱和度Sw和电阻率交会图版识别;最后,确定该油田不同类型的岩性和流体识别标准:(1)砂岩自然电位SP<45mV,中子伽马NRAT>1.4CU;泥岩60mV<SP<70mV.(2)油气层有效孔隙度10%<o<30%,含水饱和度Sw<50%,感应电阻率ILD>2.8Ω.m;水层的有效孔隙度10%<w<30%,但Sw>55%,1Ω.m<ILD<2Ω.m.结果表明:采用交会图法可以区分砂岩和泥岩不复杂的岩性;通过待测试数据对建立的交会图版进行检验,岩性和流体识别的准确率分别达到90%和98%.

Based on the crossplot method and the core data,the relationship between the features of conventional well logging curves and the lithology and fluid type of the foreign L oilfield was studied.First,in order to eliminate the differences of the logging suits in different periods,the logging data should be concluded and sorted out,such as the necessary normalization,standardization,and other pre-processing.Moreover,based on the data of core,the logging data crossplot was established,which used to verify the lithology and fluid.The lithology was identified in the SP,NGR,ILD crossplots and the fluids in the pore identified in the Sw,ILD crossplot.Furthermore,the identification standard range of different types of lithologyies and fluid type was set up for L oilfield: ①for sand: SP<45 mV,NRAT>1.4 CU;for shale: 60 mV<SP<70 mV;②for hydrocarbon bearing formation: 10%<Φo<30%,Sw<50%,ILD>2.8 Ω·m;for water bearing formation 10%<PHIE<30%,but Sw>55%,1 Ω·m<ILD<2 Ω·m.(SP as the natural potential,NRAT as neutron gamma,PHIE as effective porosity,ILD as induction resistivity,SW as water saturation) At last,the method was tested for the practical data.The results show that the method can distinguish the sandstone and shale.And the accuracy of lithology and fluid type identification is 90% and 98% respectively.The conclusion of this paper is of important value to the lithology identification and reservoir prediction of the foreign L oilfield.