摘要

Traditional formation pressure prediction methods all are based on the formation undercompaction mechanism and the prediction results are obviously low when predicting abnormally high pressure caused by compressional structure overpressure. To eliminate this problem, we propose a new formation pressure prediction method considering compressional structure overpressure as the dominant factor causing abnormally high pressure. First, we establish a model for predicting maximum principal stress, this virtual maximum principal stress is calculated by a double stress field analysis. Then we predict the formation pressure by fitting the maximum principal stress with formation pressure. The real maximum principal stress can be determined by caculating the sum of the virtual maximum principal stresses. Practical application to real data from the A1 and A2 wells in the A gas field shows that this new method has higher accuracy than the traditional equivalent depth method.

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