Evaluating Source Rock Using Logging Data—improvement And Application

Evaluating source rocks using logging information has great potential and application value because its economic, efficient, and high vertical resolution, but how to improve the calculation accuracy is a bottleneck for the further development of the methodin recent years.This article describes a variety of models of calculating the organic carbon content,and the focus is onΔlog R model which is widely used by domestic scholars. However,Δlog R model is subjecte and cumbersome by establishing a baseline value;limiting the calculatin accuracy by giving the composite coefficient in advance; the method is rough by choosing the same composite coefficient for the whole target layer throuch overall shift;The model is not conducive to accurate calculation of the organic carbon content. by using only two well logs. We analyzed the model thoroughly in this paper and proposed some improvements under the premise of the universal and accuracy of model;Proposed a new method of calculating amplitude difference—using computer recognizes the poor organic mudstone automatically and calculating amplitude difference between two curves on the basis that amplitude difference in poor organic mudstone is close to zero.With no baseline values, the method is more convenient. It is observed that detected organic carbon content is constraintd by the selected coefficient, explained theoretically the reason lies behind it and proposed the method to get the optimal coefficient;Overcome the drawbacks of the overall translation and made the calculation of amplitude difference more sophisticated and reasonable throuth calculating dynamicly—giving source rocks of different characteristics different coefficient。Bring density into the model and realize calculating organic carbon content using a variety of logging parameters under the premise of model stability and advantage of overlapping method.Compar model the paper proposed whih previous models whih actual examples,the results show that model in this paper is more accurate, objective and easy to operate, has great application value.Finally, take Changling rift as an example,introduce application methods and point out some precautions to provide guidance.for the further use of the model。...