四中子测井在剩余油评价中的应用

Application of Quad-Neutron Logging in Residual Oil Evaluation

储层在低矿化度和低孔隙度情况下,饱和度测井应用效果差,孔隙度和泥质含量计算不够准确导致剩余油误判,针对这些问题引进四中子测井。四中子测井采用镅铍中子源,通过4个探测器采集中子-中子、中子-伽马双物理过程的信息,减少对裸眼井信息的依赖;利用活化铝元素计算泥质含量;在孔隙度计算和流体识别时,综合双物理过程的测量方式减小井眼环境及流体性质影响,放大流体响应信息;较精确地评价套后地层物性特征及剩余油分布情况。多区块、多井次的现场应用证明四中子测井在剩余油评价中使用效果良好。

In the case of low salinity and porosity,the application effect of saturation logging is poor;at the same time,the calculation of porosity and shale content is not accurate enough,which leads to miscalculation of residual oil.In view of these problems,quad-neutron logging is introduced.Quad-neutron logging uses americium beryllium neutron source to collect neutronneutron and neutrongamma dual physical process information through four detectors,which reduces the dependence on open hole well information.Activated aluminum element is used to calculate shale content.When calculating porosity and identifying fluid,combined with the measurement method of dual physical process,the effect of borehole environment and fluid properties are reduced,and fluid response information is amplified,and the physical properties and distribution of remaining oil after casing can be accurately evaluated.The field application in many blocks and wells shows that quad-neutron logging for residual oil evaluation is good.