Overpressure Identification and Pressure Prediction in Yinggehai Basin

The accurate prediction of overpressure is one of the key issues that restrict the effective development of oil and gas resources in the Yinggehai Basin. In this paper, the formation mechanism of overpressure in Yinggehai Basin is studied. Based on this mechanism, the quantitative prediction model and empirical parameters of overpressure are optimized in Yinggehai Basin and applied in engineering. The results show that the formation mechanism of overpressure in the Yinggehai Basin is complicated, and the causes of overpressure in different blocks of basin are different. The eastern block mainly develops loading-type overpressure, while the Ledong block is dominated by unloading high pressure. Different blocks should employ different abnormal high-pressure prediction models. The East block mainly adopts the Eaton method, and the Ledong block mainly utilizes the Bowers method. The empirical parameters of different models can be determined according to the actual drilling conditions. The practical application demonstrates that the abnormal high-pressure prediction error is within 2%, and it is able to satisfy the requirements of on-site engineering.