西藏高海拔工作区复杂地层岩心钻探施工难点与对策

Difficulties and countermeasures of core drilling in complex strata in high altitude working area of Xizang

摘要:

西藏罗布莎工作区海拔高，地质条件复杂，岩层破碎且裂隙发育显著，地层稳定性差，存在地层破碎、漏失、缩径等钻探难题。本文聚焦该工作区设计孔深800 m的中深孔施工实践，对以破碎绿泥石化橄榄岩为主、严重漏水且缩径频繁的极端复杂地层中的施工过程进行了总结。针对人员短缺、设备组装要求特殊、严重漏水致使孔壁失稳、冲洗液易污染失效、频繁缩径引发卡钻等核心难题，系统归纳了钻机-钻塔创新组合技术、基于动态堵漏与抗污染配方的冲洗液体系优化、套管护壁结合周期性提钻扫孔防缩径、阶段性人员动态调整与快速培养模式等关键应对技术。经实践验证，此次钻孔施工成功克服了各种困难，顺利终孔。本案例对施工实践进行的系统总结和所积累的施工经验，可为类似高海拔、复杂地层条件下的岩心钻孔施工提供技术参考和管理经验借鉴。

Abstract:

Xizang Luobusha working area is located at a high altitude with complex geological conditions， featuring fractured rock layers and significant fissure development， resulting in poor formation stability and drilling challenges such as strata fragmentation， leakage， and shrinkage. This paper focuses on the construction practice of medium-deep holes designed to a depth of 800 m in this working area， summarizing the construction process in extremely complex formations dominated by fractured chlorite petrified olivine， which suffer from severe leakage and frequent shrinkage. To address core challenges such as personnel shortages， special equipment assembly requirements， hole wall instability caused by severe leakage， flushing fluid contamination and failure， and frequent shrinkage leading to stuck bits， the key technologies were systematically summarized， including innovative combination technologies of drilling rigs and drill towers， optimization of flushing fluid systems based on dynamic plugging and anti-contamination formulations， casing protection combined with periodic drilling and hole sweeping to prevent shrinkage， and phased dynamic personnel adjustment and rapid training models. Through practical verification， this drilling operation successfully overcame various difficulties and completed the hole smoothly. The case study provides technical reference and management experience for core drilling under similar conditions of high altitude and complex strata.