小秦岭整装勘查区综合普查钻探技术

Drilling technology applied during comprehensive prospecting in the Xiaoqinling integrated exploration area

小秦岭国家级整装勘查区综合物探科研钻探专项,旨在查清小秦岭地区深部地质结构及隐伏矿体的储存特征,因勘查区内没有施工过深孔,深部地质资料缺乏,施工未知因素较多,综合该钻探专项基本情况、地层岩性、钻孔深度及终孔直径,选择一套实用的钻探设备和以绳索取心钻进、LBM冲洗液体系为主要钻进工艺来满足施工需要;在施工过程中,遇到上部地层取心率低、涌水、吸附卡钻、掉块卡钻、孔内漏失、片麻岩地层防斜、起拔套管困难等技术问题,针对出现的技术问题,制定了切实可行的解决方案,对今后该矿区或类似地层钻探施工具有一定的借鉴意义。同时总结、形成了一套针对破碎、胶结性差地层的泥浆体系,在维护孔壁方面取得了良好的效果,有效预防深孔重大孔内事故,提高了施工效率,节约了钻探施工成本。

The special project of comprehensive geophysical research drilling in the Xiaoqinling national integrated exploration area aims to find out the deep geological structure and reservoir characteristics of the hidden ore bodies in the Xiaoqinling area.Due to lack of deep hole and deep geological data,many unknown factors exist in construction.Considering the basic condition of this special drilling project,strata lithology,drilling depth and final hole diameter,practical drilling equipments and wire‑line core drilling and LBM drilling fluid system as the main drilling technology should be selected to meet the construction needs.During the drilling process,technical problems such as low core recovery rate in upper strata,water gushing,adhesion stuck,falling block stuck,leakage in the hole,anti‑slope in slate layer and difficult in lifting casing were encountered.Relevant feasible solutions were made to provide certain reference for the drilling construction in this mining area or similar strata in the future.At the same time,a mud system for fractured and poorly consolidated strata was summarized and formed,which has achieved good results in maintaining the well wall,effectively preventing major accidents in deep holes,improving drilling efficiency and saving drilling costs.