磷石膏地层用钙基成膜环保冲洗液研究与应用

Development and application of calcium-based film-forming environment-friendly drilling fluid for phosphogypsum formation

针对磷石膏地层水平孔钻探工程存在松散磷石膏层孔壁坍塌、磷石膏遇水分散影响取心质量、冲洗液受钙侵导致其性能恶化以及钻孔轨迹控制困难等技术难题,同时满足绳索取心钻进工艺要求,室内针对性地开展了冲洗液技术研究,分析了磷石膏地层水平孔钻进对冲洗液性能的要求,并在室内处理剂优选、配方优化的基础上,研发了钙基成膜环保冲洗液体系,并成功应用于贵州某磷石膏矿尾矿库中的水平孔钻探工程。室内试验及现场应用结果表明,该体系具有良好的抗钙侵能力,滤失量低,流变性能相对稳定;能够在岩心表面形成相对坚固的保护膜,强化磷石膏孔壁,有效预防孔壁坍塌;保护岩心免受冲洗液侵蚀,提高了取心质量。此外,该体系由无毒和易降解的环保材料组成,具有良好的环保性能。

Regarding to the technical problems of loose phosphogypsum hole wall collapse, dispersion of phosphogypsum encountering water, calcium contamination of drilling fluid and difficulty in drilling trajectory control during horizontal hole drilling in phosphogypsum formation, the research on drilling fluid technology was carried out indoors with analysis of the requirements of horizontal hole drilling in phosphogypsum formation for the performance of drilling fluid. The calcium-based film-forming environment-friendly drilling fluid was developed and successfully applied to horizontal hole drilling at a depository of phosphogypsum tailings in Guizhou. Laboratory test and field application results indicate that the system has good resistance to calcium intrusion, low filtration loss, and relatively stable rheological properties. A relatively strong protective film can be formed on the core surface, which can effectively prevent the hole wall collapse and protect core. In addition, the system consisting of non-toxic and biodegradable materials has good environment protection performance.