青海省某盐湖浅层卤水矿岩心钻探技术

Core drilling technology for shallow brine mine in a salt lake in Qinghai Province

摘要:

盐湖浅部覆盖地层具有水溶性强、胶结性差、裂隙孔隙发育等特点，钻孔易发生缩径、坍塌、溶蚀剥落、漏失等问题，进而引起卡钻、埋钻、憋泵等孔内事故，因此需要改进钻探技术以提升工程施工质效。结合矿区实际，探索了短钻具+侧喷PDC钻头+饱和卤水冲洗液+PVC管护壁组合式绳索取心钻进工艺，通过开展试验研究，优化钻进参数、改善饱和卤水冲洗液、优选取心钻头，因地制宜改造绳索取心绞车，设计研发分层抽水试验装置的单双动接头，这些技术措施在盐湖浅层钻探施工生产中取得成功应用，保障了钻探工程高质高效实施。

关键词:卤水矿;绳索取心;PDC钻头;饱和卤水冲洗液;盐湖

Abstract:

The shallow overburden of salt lake has the characteristics of strong water solubility， poor cementation， developed fractures and pores， etc. Boreholes are prone to problems such as diameter shrinkage， collapse， corrosion peeling， leakage， etc.， which further leads to borehole accidents such as tool stuck， drill buried， pump suppression， etc. Therefore， it is necessary to improve drilling technology to promote the quality and efficiency of engineering construction. Combined with the actual situation in the mining area， the project explored the combined wire-line core drilling technology of “short drilling tool+side-sprayed PDC bit+saturated brine flushing fluid+PVC tube protection wall”， by carrying out experimental research， optimizing the drilling parameters， improving the saturated brine flushing solution ， preferably selecting the core bit， modifiying the wire-line coring winch according to local conditions， designing and developing the single-double action joint of layered pumping test device， these technical measures were successfully applied in shallow drilling construction and production of salt lake， which ensures the high-quality and efficient implementation of drilling engineering.

Key words:brine mine;wire-line coring;PDC bit;saturated brine flushing fluid;salt lake