Research and Application of Integrated Geological Engineering Technology for Deep High-Pressure Wells in the Bozhong Sag

The geology of the deep buried hills in the Bozhong Sag of the Bohai Bay Basin are complex, with deep burial of the target layer, multiple geological layers encountered during drilling, complex and variable lithology, and significant changes in the formation pressure system. During the drilling process, complex situations frequently occur, and weak layers are prone to leakage, which affects the exploration and development process. By predicting the risk of wellbore leakage before drilling, correcting formation pressure, making scientific decisions in the high-pressure section during drilling, accurately capturing the buried hill interface, and identifying and controlling the formation pressure of the buried hill while drilling, the drilling design and adjustment plan optimization during drilling were achieved, and an integrated geological engineering technology for the whole process of deep high-pressure wells in the Bozhong Sag was established. After the application of the integrated geological engineering technology throughout the whole process in 20 deep high-pressure exploration wells in Bohai Oilfield, the drilling complexity was reduced by 60%, and the processing time for complex situations such as wellbore leakage and overflow was reduced by 40%. The accuracy of identifying buried hill interfaces was 100%, and the cost of a single well was reduced by more than 30 million yuan. The integrated geological engineering technology for the whole process provides a technical approach for deep and ultra-deep exploration and development of Bohai Oilfield, and it has good application prospects.