南海流花海域钻井安全钻井液密度窗口计算分析

为了准确确定安全钻井液密度窗口,并维持钻井过程的井壁稳定成为制约南海海上油气开发目前所面临的重要问题。针对该问题,基于流花海域LH20-2油田各已开发井的声波时差及其他测井数据,利用Eaton法对该构造的孔隙压力分布规律进行了预测。此外,对该地区地层的破裂压力和坍塌压力随井斜角和方位角的分布规律进行了定量分析,最终得到了各井段安全钻井液密度窗口。结果表明,油田孔隙压力分布范围在0. 98～1. 05 g/cm~3,处于正常压力系统内。并且得出,拟开发井直井段和水平段安全钻井液密度窗口依次是1. 07～1. 10 g/cm~3和1. 22～1. 25 g/cm~3。此研究可以为南海LH20-2油田拟开发井钻井液设计提供依据和参考。

Determination of Safe Mud Weight Window in Liuhua Area of South China Sea

In order to accurately determine the safe mud density window and maintain the wellbore stability of the drilling process, which has become an important problem that restricts the offshore oil and gas development in the South China Sea. Aiming at this problem, based on the acoustic time difference and other logging data of each developed well in the LH20-2 oilfield in the Liuhua area, the pore pressure distribution of the structure was predicted by the Eaton method. In addition, the rupture pressure and collapse pressure of the strata in this area are quantitatively analyzed with the distribution of the inclination angle and azimuth angle of the well, and finally the safety mud density window of each well section is obtained. The results show that the pore pressure distribution of the oilfield ranges from 0.98 to 1.05 g/cm3, which is in the normal pressure system. It is also concluded that the safety drilling fluid density window of the straight well section and the horizontal section of the proposed development well is 1.07-1.10g/cm3 and 1.22-1.25g/cm3.This study can provide a basis and reference for the design of drilling fluids for the development of the LH20-2 oilfield in the South China Sea.