基于岩石成因的测井地质属性研究方法

Method about the geological attribution research of well logging based on lithogenesis

测井曲线是多成因的产物.从测量成因看,它与测井仪器的原理密不可分;从测量对象看,它与地质背景相互关联;从井眼环境看,它也包含井眼条件的变化信息.由此可见,测井曲线本身就是地球物理、地质及工程等多因素的响应纠缠体,其中,每一种因素,因其测井响应的成因条件完全不同,它只会按自身固有模式变化.前人对于测井曲线的仪器成因研究较系统,因此,基于仪器原理的测井评价方法也比较成功,但对于地质背景与测井曲线的成因关系识别一直缺乏有效方法,致使测井曲线本身内含的地质信号难以得到有效利用.根据地质成因的某一固有机理,推测或在测井曲线上寻找与该固有机理相吻合的共性变化,是研究测井曲线内含地质属性的一个可能途径,岩石成因就是一个值得探索的切入点.研究表明,岩石成因的主要差别在于形成条件不同,岩石形成条件是决定测井曲线内含地质专属性特征的要因之一.本文分别从成岩时期、成岩物质、成岩温度、沉积相、成岩相及物性特征等多个岩石成因条件的差异,讨论了岩石成因条件的差异与测井地质属性识别的关系.

Well logging curves are the product of multi-genesis.From the part of the principle of measurement, the curves are closely connected with the principle of logging instruments. In the view of measuring object, the curves are associated with the geological background. Look from the borehole environment,the curves also contain the changing information of borehole conditions.Therefore, well logging curves are comprehensive response of geophysical,geological and engineering factors. Among them,each kind of factor,because the cause of its logging response condition is completely different,it will only according to the inherent pattern changes. Predecessors had a systematically research about instrument origin of well logging and had a successfully research about well logging evaluation method based on instrument ＇s principle. However, for the relationship identification between geological background and well logging curves,they have been lack of effective method. The geological signal hidden in the well logs are hardly to be used. According to a certain inherent mechanism of the geological genesis,speculate or find the common change on the well logging curves may be is a possible way to study the geological attributes of the well logs. Lithogenesis is a point cut and worth exploring. The study shows that the main difference among lithogenesis is formation conditions. Rock formation condition is the decisive factor which decides the geological attributes that are hidden in the well logging curves. From the multiple differences of lithogenesis conditions such as diagenetic period, diagenetic substance,diagenetic temperature,sedimentary facies,diagenetic facies and physical property,the paper discusses the identification relationship between the difference of lithogenesis conditions and the geological attribution of well logging.