Core drilling technology practice in the karst area of Southwest Guangxi

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.