Wells monitoring method of movable water saturation between using gadolinium tracing neutron gamma energy spectrum

A method for estimating the residual petroleum reserve in oil field and the useful regions features that the Gd instead of tritium is used as tracing agent in interwall monitor, the well logging is combined with the sampling at well mouth, and the saturation degree of the flowing water in stratum is measured. It includes such steps as measuring the neutronic gamma base line of water injection well and oil well, injecting tracing agent Gd inw ater injection well, measuring the tracing cross-section, logging the oil well while sampling at well mouth, and analyzing reservoir by reservoir. 本发明为"井间钆示踪中子伽马能谱可动水饱和度监测方法"，其核心技术是在井间监测中用钆代替氚做示踪剂，将井口取样单一监测方法扩展为井下测井和井口取样综合监测方法，将监测目标从测定地层含水饱和度改变为测定地层可动水饱和度。在施工时先在注水井和采油井测量中子伽马基线，在注水井注入钆示踪剂，并测量中子伽马钆示踪注水剖面。此后，在相关采油井进行测井与井口取样双重监测，经综合分析分小层求出可动水饱和度井间分布。此项发明可用于注水开发油田高含水期监测可动水饱和度分布和划分水淹等级，进而估算剩余油储量和有利区块。与现有的井间示踪方法相比，在厚层细分、薄层评价和用一种示踪剂实现多层监测等方面具有优势。