两种碳酸盐岩地层孔隙压力计算方法的比较分析

准确预测地层孔隙压力是安全钻井,防止井壁失稳的关键。针对碳酸盐岩地层孔隙压力预测难度大这一问题,在分析碳酸盐岩地层特性的基础上,运用Eation法和有效应力法,通过以L1井为例,计算讨论了这两种方法在碳酸盐岩地层压力预测计算时的适用性。通过与实测值的比较分析,认为Eaton法对于碳酸盐岩地层压力的计算误差较大,不能准确计算其地层压力,而有效应力法更适用于以泥质含量少为特点的碳酸盐岩地层。

Comparative Analysis on Two Calculation Methods of the Pore Pressure in Carbonate Formation

The accuracy of predicting the formation pore pressure is a key to safe drilling and preventing the wellbore instability. In this paper, in order to solve this problem that the prediction of carbonate formation pore pressure is difficult, carbonate formation characteristics were analyzed; taking well L1 as an example, the applicability of Eaton method and effective stress method in carbonate formation pressure prediction was discussed. Through comparing with measured values, it＇s pointed out that the effective stress method is more suitable for carbonate formation in which shale content is lower; Eaton method can not accurately calculate the carbonate formation pressure because of its larger error.