压敏储层深水平井井壁稳定性研究

Study on Well-bore Stability of Pressure-sensitive Deep Reservoir Wells

塔中I号气田碳酸盐岩储层孔隙发育,喷漏同层,再加上埋藏较深,大都采用深水平井开发,井壁失稳是钻进中的难点.井壁坍塌和地层破裂两种情况都会导致井壁失稳.本文建立了裸眼井壁坍塌、破裂压力模型,以中古12-1H为例,在5 345-5 350m、5 385-5 387m、5 397-5 400m井段,坍塌压力和地层压力非常接近,极易漏失;由于是裂缝性储层,孔隙连通,漏失后可能会产生井喷.针对这种情况,应该采取控压钻井或者欠平衡钻井方式,论文结论对于指导塔中裂缝储层安全钻井具有重要意义.

The development of carbonate reservoir in field of the tower I ,which is based on the devel-opment of deep buried depth ,is the difficult point in drilling .The collapse of the shaft lining and the rup-ture of the formation ,can lead to the instability of the well-bore .The open hole wall collapse and fracture pressure model are established in this paper ,in medieval 12-1H for example ,in the sections of 5345-5350m ,5385-5387m and 5397-5400m ,to show that the collapse pressure and formation pressure is very close and easy to cause leakage ,because it is the fractured reservoir with pore connectivity and leakage makes blowout .In view of this situation ,it is important to adopt the control pressure drilling or the unbal-anced drilling method .The conclusion of the paper is very important for the safety drilling of the fractured reservoir .