Prediction of organic carbon content and analysis of influencing factors in Taiyang shallow shale gas field
In the self-generated and self-stored unconventional shale gas reservoirs,the variation of reservoir difference is not obvious at the macro level,and it is difficult to identify sweet spots.In order to solve the difficulty in identifying and evaluating high-quality reser-voir in the process of horizontal well drilling during the development period,the identification of organic-rich layer is the key prerequi-site for identifying and evaluating high-quality reservoir based on organic matter as the material basis of shale gas.By analyzing the log-ging response characteristics of organic carbon content(TOC)of shale,it was found that the uranium curve and volume density curve of natural gamma spectrum had a good positive correlation with TOC,and their multivariate fitting can accurately characterize TOC quanti-tatively and continuously.The distribution characteristics of TOC were clearly controlled by the use of thorium-uranium ratio to reflect the depth of ancient sedimentary water and biogenic silicon content to reflect ancient productivity.Based on the commonality of forma-tion elements in logging and logging,organic-rich layers can be identified by using logging while drilling data,it was found that m(Si)/m(Si+Al+Fe),m(Ni)/m(Al),m(Mo)/m(Al),and other elements in XRF logging can also reflect the relative changes in biogenic silicon content and ancient redox environment within a single well,consistent with the trend of TOC changes.This feature has a good ap-plication effect on target oriented optimization of horizontal well drilling and can be used to guide the development and implementation of similar shale gas reservoirs.
shallow shale gasLongmaxi Formationorganic carbon contentTaiyang gas filedbiogenic silicon
万方数据
维普
