地层坍塌压力的计算及在新站地区的应用

CALCULATION OF FORMATION CAVING PRESSURE AND ITS APPLICATION IN XINZHAN AREA

新站地区地质情况比较复杂,在钻井施工过程中极易发生井塌等情况,严重者由于井塌而导致了新钻井被迫报废进尺。井壁不稳定问题已严重制约着新站地区的钻井作业,并带来了很大的经济损失。如何合理地计算地层坍塌压力,给出合理的钻井液密度,是新站地区最为关心的问题。首先通过岩石力学理论,建立起地层坍塌压力计算模型,并给出模型中的参数与测井数据之间的关系,进而利用新站地区的常规测井资料连续地计算了该区的地层坍塌压力,从而有效地指导了钻井施工,收到了良好的效果。

Geological circumstance in Xinzhan area is complicated and borehole collapses occur easily during drilling operations that result in borehole obsolescence. And the drilling operations in Xinzhan area have been influenced by unstable borehole walls, and economic loss is heavy. Therefore, the key problem in this area is to obtain reasonable drilling fluid density by means of figuring out right formation caving pressure. In this paper, on the basis of rock mechanics, a model on calculating formation caving pressure is established, and the relation between parameters in the model and logging data is given. Then, the formation caving pressures in this area are calculated continuously by using the conventional logging data, as a result, drilling operations are effectively instructed and good results are obtained.