西藏羌塘盆地中深孔岩心钻探质量控制体系与工程实践

Quality control system and engineering practice of medium-deep core drilling in Qiangtang Basin， Xizang

摘要:

针对西藏羌塘盆地高海拔、高寒缺氧、膏盐?灰岩互层易漏失缩径、高原生态敏感等特殊条件，以QS6孔901.50 m中深孔岩心钻探工程为依托，构建“钻前策划—过程严控—核验归档—闭环改进”全流程质量控制体系。从岩心采取率、钻孔弯曲度、孔深精度、简易水文观测、原始资料、封孔作业及质量监督7个维度建立控制指标与技术措施。工程实践表明：该孔岩心采取率98.44%，全孔最大顶角2.0°，孔深校正误差≤2 cm，无孔内事故与机械故障，原始资料规范、封孔质量合格，各项指标均优于设计及《地质岩心钻探规程》要求。所形成的高原中深孔钻探质量控制模式，可有效保障复杂地层条件下钻探成果可靠性，为青藏高原矿产调查评价钻探提供技术支撑。

Abstract:

In response to the special conditions in the Qiangtang Basin， Xizang， such as high altitude， severe cold and oxygen deficiency， prone to loss and diameter reduction in the interbedded potash-limestone formations， and ecologically sensitive plateau environments， a full-process quality control system of "pre-drilling planning， strict in-process control， verification and archiving， closed-loop improvement" was established based on the 901.50 m medium-deep core drilling project of QS6 drilling hole. The control indicators and technical measures were established from seven dimensions， including core recovery， borehole deviation， depth accuracy， simple hydrological observation， raw data， hole sealing operations， and quality supervision. The engineering practice shows that the core recovery rate of this drilling hole reached 98.44%， the maximum hole inclination was 2.0°， the depth calibration error was ≤2 cm， and no in-hole accidents or mechanical failures happened， in addition， the raw data were standardized， the drilling hole sealing met the quality requirements and all indicators surpassed the design specifications and the requirements of the "Geological Core Drilling Code". The resulting quality control model for medium-deep drilling in the plateau can effectively ensure the reliability of drilling results under complex strata conditions， providing technical support for mineral survey and evaluation drilling in the Qinghai-Xizang Plateau.