准噶尔盆地环玛湖斜坡区异常高压成因机理分析及压力预测方法

随着油气勘探的发展，人们逐渐认识到地层压力对油气保存和单井产能的高低均有较大影响，因此 有必要利用地震资料对地层压力进行定量预测。 目前，广泛应用的异常地层压力预测方法是建立在有效 应力理论基础上的，该理论由 Terzaghi 提出，并在疏松介质的力学分析中发挥了很好的作用，但是由于多孔介质物质结构的复杂性，有效应力原理在多孔介质中的应用具有一定的局限性。 在考虑了岩石物理性 质和力学平衡原理的基础上，通过引入孔隙度参数得到了双重有效应力方程，使上覆岩层压力、地层压力 和岩石骨架应力之间的关系更合理，进而建立了一种基于多孔介质有效应力原理的地层压力预测新模型。 通过对准噶尔盆地西北缘环玛湖斜坡区异常高压成因的分析，在地质成因的约束下利用新的压力预 测模型对研究区的地层压力进行了预测。

Genetic mechanism analysis and prediction method of abnormal high pressure in Mahu slope area,Junggar Basin

With the development of the oil and gas exploration, it is gradually recognized that the formation pressure has important effect on the hydrocarbon preservation and individual well deliverability. So it is necessary to quantitatively predict the formation pressure based on the seismic data. The prediction method of abnormal formation pressure widely applied now is based on the effective stress theory which is proposed by Terzaghi in 1923 and plays an important rolein civil engineering practice. However, the effective stress theory has limitations in the porous medium which has complex structure. Considering the rock physical properties and mechanics equilibrium principle, we developed a new pressure prediction method based on the dual effective stress of porous medium through the introduction of dual effective stress equation related to porosity, making closer relationship among the overburden pressure, formationpressure and rock skelecton stress. We achieved good effect after putting this method in practical use to the formations in Mahu slope area, northwest of the Junggar Basin, through the analysis of the genesis of abnormal high pressure andconstrained by the geological origin.