昆北油田切12区下干柴沟组下段Ⅲ油组岩屑测井识别

Logging-Based Debris Identification of Ⅲ Oil Member in Lower Section of Lower Ganchaigou Formation in Block Qie12, Kunbei Oilfield

针对柴达木盆地昆北油田切12区下干柴沟组下段Ⅲ油组砂砾岩、高阻层识别难度大的问题,利用岩心、薄片、试油、测井等资料,应用地质、测井综合分析方法,探讨了岩屑含量的测井响应特征与定量计算方法,并将其应用于单一砂砾岩层中物源方向研究、主分流河道确定、高阻水层识别和岩性引起的高阻层感应电阻率校正。岩屑含量与测井曲线的幅度存在一定关系,根据这一关系,建立声波时差和感应电阻率计算岩屑含量的方程,并根据由岩屑含量变化引起的声波时差和感应电阻率变化量的关系,建立了感应电阻率校正方程;通过对岩屑含量变化引起的高感应电阻率异常值的校正,解决了研究区高阻水层的识别和由高阻岩屑引起的含油饱和度误差校正问题。

Regarding the difficulties in identifying the sandy conglomerate and high-resistivity layers in the Ⅲ oil member of the lower section of lower Ganchaigou formation in the Block Qie12 of Kunbei oilfield,Qaidam basin,using the data of core,thin section,formation test, logging and a geology-logging combined analysis method,the paper discusses the logging responses of rock debris content and its quantitative calculation methods,and then applies these methods into identifying sedimentary source orientation,major distributary channel and high-resistivity aquifer and lithology-induced induction resistivity correction in high-resistivity layers.Log responses are related to debris contents,based on which,an equation of debris content calculated from interval transit time and induction resistivity,and an induction resistivity correction equation have been established based on the relationship between interval transit time and induction resistivity variation.The high induction resistivity after correction can be used to solve the problems in identifying high-resistivity aquifer and correcting the oil saturation errors caused by high-resistivity debris.