桂西南岩溶地区岩心钻探技术实践

Core drilling technology practice in the karst area of Southwest Guangxi

摘要:

在桂西南某矿区外围部署的岩心钻探工程，钻遇了岩溶裂隙带、串珠型小溶洞、大型溶洞等多种典型岩溶问题，孔内存在失返性漏失、孔壁不稳定、管柱弯曲等复杂情况。现场通过采取相应的钻进工艺并配合堵漏措施，完成了工程施工。在岩溶复杂地层段优化孔身结构，保持孔壁稳定；采用顶漏钻进穿越串珠型小溶洞地层；在大型溶洞内通过对管柱弯曲进行可行性分析，采用相应技术措施降低管柱弯曲，同时采用投料堵漏法建立循环。通过梳理桂西南地区岩心钻探过程中钻遇的多种复杂情况，总结了相应的处理技术措施，以期为类似岩心钻探工程提供参考。

Abstract:

Various typical karst problems， including karst fissure zones， bead-like small karst caves， and large karst caverns are encountered in a core drilling project deployed in the periphery of a mining area in Southwest Guangxi. Complex downhole conditions exist such as lost circulation， unstable borehole walls， and pipe string buckling. Field construction was successfully completed by implementing corresponding drilling techniques alongside plugging measures， that is optimizing the borehole structure in complex karst formations to maintain borehole wall stability， adopting drilling with lost circulation technology when drilling across bead-like small cave formations， conducting feasibility analysis of pipe string bending in large caverns， adopting corresponding technical measures to reduce string bending， and using material-feeding plugging methods to re-establish circulation. By systematically reviewing the multiple complex situations encountered during core drilling in the Southwest Guangxi region， corresponding technical countermeasures have been summarized， aiming to provide references for similar core drilling projects.