西南天山复杂地层绳索取心钻探跑钻事故处理方法

Treatment of drilling string falling‑off in wire‑line core drilling in complex strata of Southwest Tianshan Mountains

新疆西南天山萨尔干矿区地层极其破碎复杂,近年来施工的钻孔多全孔破碎、漏失,钻进过程中时有掉块、卡钻、钻孔坍塌等现象发生,严重时发生孔内事故,施工难度较大。本文结合该区一例钻孔施工案例,介绍了破碎复杂地层取心钢丝绳断裂导致岩心内管脱落,进而引发严重跑钻事故的处理过程以及注意事项。结合现场事故情况,通过导向扩孔钻进等方法有效地处理了该起复杂事故,使钻孔得以顺利终孔,取得了所需地质资料,挽回了经济损失。

The strata in the Sargan area of Tianshan Mountains in southwest Xinjiang are extremely fractured and complex.In recent years,many holes have been drilled through broken and lost circulation formation where falling blocks,stuck drilling and hole collapse happened frequently.In reference to a drilling case in this area,this paper introduces the treatment process and cautions for treatment of the serious drilling accident of drilling string falling‑off due to breaking of the coring wire line in the fractured complex strata.With analysis of the accident,guided reaming was adopted to deal with the complex accident effectively.As a result,the hole was successfully finished with the required geological data obtained,and some economic losses were recovered.