宁夏中卫市深井勘查区松散破碎地层冲洗液护壁技术方法

Drilling fluid wall protection technology for loose and fractured strata in the Shenjing exploration area in Zhongwei City， Ningxia

摘要:

在宁夏中卫市深井勘查区煤炭资源勘探项目钻探施工初期，由于地层条件复杂，岩石松散破碎、漏失，钻孔护壁难度大，导致岩心采取率不达标，施工效率低、成本高，钻机台月效率仅为353 m/台月。通过分析勘查区岩土工程地质特征和岩石物理力学性质，调整了施工工艺和钻进参数，优化了冲洗液配方，采用了低固相聚合物成膜护壁冲洗液体系，改善了冲洗液护壁效果和护心效果，冲洗液滤失量由25 mL/30 min降为9 mL/30 min，降低64%；平均岩心采取率由53%提高至84.41%，提高31.41%；平均台月效率提高至757.87 m/台月，提高115%。后续施工的9个钻孔施工顺利，累计完成钻探进尺4774.6 m，对类似地区钻探施工提供了借鉴。

Abstract:

At the initial stage of drilling in the coal resource exploration project of the Shenjing exploration area in Zhongwei City， Ningxia， the complexity of the geological conditions， characterized by loose， fractured， and loss-prone strata， presented significant challenges in borehole wall stabilization. This led to substandard core recovery rates， reduced construction efficiency， and increased costs， with the drilling rig's monthly efficiency reaching only 353 m. By analyzing the geotechnical engineering characteristics and rock physical-mechanical properties of the exploration area， adjustments were made to the construction techniques and drilling parameters. The drilling fluid formula was optimized， and a low-solid-phase polymer film-forming wall stabilization drilling fluid system was adopted. These measures improved both the wall stabilization and core protection effectiveness of the drilling fluid. The filtration loss of the drilling fluid decreased from 25 mL/30 min to 9 mL/30 min， a reduction of 64%. The average core recovery rate increased from 53% to 84.41%， an improvement of 31.41%. The average monthly rig efficiency increased to 757.87 m， an increase of 115%. Subsequent construction of 9 boreholes proceeded smoothly， achieving a cumulative drilling footage of 4774.6 m. This experience provides a valuable reference for drilling in similar regions.