井壁稳定性的研究

钻井过程中的井壁失稳现象普遍,不仅增加了钻井作业的难度,而且使固井质量难以保证.井壁坍塌主要是井内钻井液液柱压力过低不能对井壁提供足够的支撑所造成,而井壁发生破裂是井内钻井液液柱压力过大而造成的.通过研究,推出不会产生井壁失稳所需的钻井液密度的计算公式,以便施工人员采用合理的钻井液,保证快速、安全地实施钻井过程.

Study of Wellbore Stability

Nowdays, it is the most common phenomenon that the stability of the wellbore is one of the most important considerations in any angle wells. It not only increases the difficulty of the drilling, but also easily makes the wellbore instability. The wellbore collapses attribute to the drilling fluid pressure being low to the formation, and the wellbore fracture is caused by too large drilling fluid pressure. From the study of the wellbore, it is the most important to calculate the density of the drilling fluid when the wellbore instability will occur, so that workers can adopt the reasonable drilling fluid which can be benefit to the drilling. So it is important to study wellbore instability by the formula of the drilling fluid.