一种基于碳氧比测井的高灵敏度含油饱和度监测方法

An Enhanced Sensitivity Method to Monitor Oil Saturation by Carbon-Oxygen Ratio Logging

利用套管井中碳氧比测井能够进行含油饱和度定量评价,但需要洗井消除井筒中油的干扰。针对井眼含油性对定量计算储层含油饱和度的影响,基于双探测器碳氧比测井仪器,分析了探测器记录的井眼和地层双重介质的次生伽马射线贡献,模拟研究了不同井眼流体和地层条件下碳氧比关于孔隙度的响应规律;组合双探测器信息提取纯地层碳氧比值,建立了储层含油饱和度解释模型,提高了含油饱和度评价灵敏度。模拟结果和现场实例表明该方法计算的含油饱和度误差低于1%,为储层含油饱和度的定量监测提供一定的技术支持。

Carbon-oxygen ratio logging realizes the quantitative evaluation of oil saturation in cased wells,but the well flushing is required to eliminate the disturbance of oil in the borehole.Aiming at the influence of borehole oiliness on the quantitative calculation of oil saturation,we analyze the secondary gamma-ray contribution of the borehole and formation dual medium recorded by the detector and simulate the response law of C/O on porosity under different borehole fluids and formation conditions based on the dual-detector Carbon-Oxygen ratio logging tool.The C/O parameters of pure formation are extracted by combining dual detector information,and the oil saturation interpretation model of the reservoir is established,which improves the sensitivity of oil saturation evaluation.The simulation and field examples show that the error of oil saturation calculated by this method is controlled within 10%,which provides certain technical support for quantitative monitoring of reservoir oil saturation.