Method for Predicting Formation Pressure in Anomalously High-Pressure Mudstone Section at the Southern Margin of Junggar Basin
The mudstone section of Anjihaihe Formation in the southern margin of Junggar Basin is characterized by abnormally high pressure.The genetic mechanism of abnormal pressure is not clear.Moreover,the mudstone section exhibits strong fluid sensitivity,which can lead to deviation in well logging data and is not conducive to formation pressure prediction.To address this issue,considering the impact of fluid actions on the physical parameters of mud-stone,a well logging property correction method is established.On this basis,the formation mechanism of abnormal high pressure in mudstone formation is revealed by combining sound velocity-density curve and comprehensive com-paction curve.A multi-parameter formation pressure prediction method for the mudstone section has been devel-oped,combining effective stress theory and multiple regression analysis method.The results indicates that the genetic mechanisms of high pressure in the mudstone formation at the southern margin of Junggar Basin include undercom-paction,tectonic compression,and tectonic compaction.After logging correction,with the increase of effective stress,the longitudinal wave time difference,porosity,natural gamma and average horizontal stress of mudstone decrease,while the density increases.The effective stress is linearly related to the longitudinal wave time difference,density and porosity,and exponentially related to the natural gamma and average ground stress.Based on these findings,a well logging prediction method for mudstone formation pressure is constructed and its applicability has been veri-fied.The research outcomes contribute to the design of drilling schemes in the study area and are of significant im-portance for the efficient exploration and development in the southern margin of Junggar Basin.
mudstoneabnormally high pressurepressure predictionwell logging correctioneffective stressJunggar Basin
万方数据
维普
