异常地层压力数学模型分析与应用

ANALYSIS AND APPLICATION OF OVERPRESSURE MODELS

本文系统地论述了建立多机制异常压力数学模型的描述方法,推导了欧拉型和拉格朗日型压力方程。利用压力方程的无因次式和渗透率反演,分析和讨论了几种生压机制对形成异常压力的相对贡献。二维拉格朗日型模型的数值模拟采用了局部坐标变换和有限分析数值法,较好地解决了等时性、等岩性、断层和剥蚀等难题,提高了模拟精度。在辽东湾盆地某测线的应用中获得了满意的结果。

This paper has a systematic discussion on the description method to establish multi-mechanism model of abnormal pressure , and gives a brief derivation of Eulerian and Lagrangian type pressure equations in a unified way. It is of help for clarifying the confusion in the model establishing. The relative importance of several mechanisms which produce overpressure has been analyzed and expounded by means of nondimensional pressure equation and inverse permeability. These methods provide some general criteria and magnitude estimation of geopressure occurrence. The numerical simulation of two-dimensional overpressure model in Lagrangian reference frame is treated by the finite analysis method in local coordinate transformation. The geological difficulties, such as isochroneity, isolith, erosion, faults and others, are solved well. The results applied to some seismic profiles in the Liaodong Bay Basin are satisfactorily coincident with the observation.