基于电成像的高分辨率电阻率提取方法与应用  

High-Resolution Resistivity Extraction Method Based on Fullbore Formation Micro-Imager and Its Application

作　　者：张凯 曹志锋 蔺敬旗 王先虎 李晴晴 周炬锋 ZHANG Kai;CAO Zhifeng;LIN Jingqi;WANG Xianhu;LI Qingqing;ZHOU Jufeng(Xinjiang Branch,China National Logging Corporation,Karamay,Xinjiang 834000,China)

机构地区：[1]中国石油集团测井有限公司新疆分公司,新疆克拉玛依834000

出　　处：《测井技术》2023年第1期62-66,72,共6页Well Logging Technology

基　　金：中国石油天然气集团有限公司重大科技专项“陆相中高成熟度页岩油勘探开发关键技术研究与应用”(2019E-2603)。

摘　　要：页岩油气具有厘米级的薄互层特征,现有电阻率测井受仪器分辨率、围岩等影响较大,不能客观反映地层真实电阻率值和准确识别薄层,导致有效厚度和含油饱和度等关键储量参数的计算精度较低。基于电成像资料高分辨率的优势,开展了页岩油气储层电成像的高分辨率电阻率提取方法研究。采用常规深电阻率曲线对电成像数据按深度逐点刻度,通过数理方法计算各个深度点电阻率分布的概率密度,采用高概率密度平均的方法构建高分辨率地层电阻率的计算模型。结果表明:基于电成像可以提取高分辨率电阻率曲线,其分辨率可以达到0.5 cm,形成了厘米级薄互层测井评价的关键技术。该方法应用于页岩油储层含油饱和度的计算,可以大幅度提高基于阿尔奇公式计算的含油饱和度精度,结果与岩心分析饱和度绝对误差小于3%,满足页岩油饱和度精度的要求。Shale oil and gas is characterized by cm thin interbed.The existing resistivity logging is greatly affected by the instrument resolution and surrounding rock,which can not objectively reflect the true resistivity and thickness value of the thin bed.As a result,the calculation accuracy of key reserve parameters such as effective thickness and oil saturation is low.Based on the advantages of high resolution of the fullbore formation micro-imager data,the high resolution resistivity extraction method of the fullbore formation micro-imager of shale oil and gas reservoir is studied.The conventional deep resistivity curve is used to scale the electrical imaging point by point according to the depth,and the probability density of the resistivity distribution at each depth point is calculated by mathematical method.The high probability density average method is used to build the calculation model of the high-resolution formation resistivity curve.The results show that high-resolution resistivity curves can be extracted by fullbore formation micro-imager with a resolution of up to 0.5 cm,forming a key technique for cm thin interbed log evaluation.When the method is applied to the calculation of oil saturation of shale oil reservoir,the accuracy of oil saturation calculated based on Archie’s formula can be greatly improved.The absolute error between the result and core analysis saturation is less than 3%,which meets the requirement of the accuracy of shale oil saturation.

关 键 词：页岩油气 电成像 数理统计 地层电阻率 高分辨率 

分 类 号：P631.84[天文地球—地质矿产勘探]