Geological Mechanism Analysis of Mud Loss in Hangjinqi Area of Ordos Basin
During the drilling process in the Hangjinqi area of the northern Ordos Basin,mud losses occur frequently.In order to clarify the geological mechanism of mud loss,drilling,mud logging,well logging and other data from the Hangjinqi area were used to analyze the-characteristics of mud loss,the layers and regions where mud losses occur in the study area.The results indicate that the mud loss areas are mainly located in the mudstone of the Liujia-gou Formation,the reservoir of the Lower Shihezi Formation,and the weathered crust at the top of the Proterozoic.The mainmud loss mechanismin the mudstone of the Liujiagou forma-tion lies in its easy breakabilityand poor pressure bearing capacity.The mud loss is mainly controlled by faults,folds,and fractures generated by the weathered crust;The reservoir of the Lower Shihezi Formation is affected by faults and develops high angle fractures;cracks develop near the weathered crust at the top of the Proterozoic.Based on the geological mech-anism of mud loss,the following early warning methods are proposed:big data analysis method for mud loss,complex structure identification method,and reservoir exploitation a-nalysis method,which have a positive effect on preventing mud loss.
NETL
NSTL
万方数据
维普
