大牛地气田低压低渗地层固井技术研究

Research on Cementing Technology of Low Permeability and Pressure Layers in Daniudi Gas Field

针对大牛地气田在勘探开发初期固井质量非常不稳定这一难题,开展了对工程地质、钻井液、水泥浆等情况的分析研究,研究中采用了实验对比的方法,发现了影响固井质量的主要因素。针对这些不利因素,采用颗粒级配原理优化了水泥浆组成,并提高了水泥浆防气窜性能;依据混合能量对水泥浆性能影响规律,优化了现场水泥浆试验流程;使得水泥浆入井性能与室内实验结果一致,并达到设计要求。同时通过采用钻井液性能优化、抑制井壁坍塌和改进现场施工工艺等技术措施,优化了井眼条件,为提高水泥浆顶替效率打下良好基础。研究结果经现场应用,取得了优良的固井质量,解决了固井质量不稳定的问题,保证了气田勘探开发的顺利进行。

Cementing quality is often poor in Daniudi Gas Field in the beginning of exploration, so we carried on the analysis of the engineering geology, drilling fluid and mud, and so on, and got the main factors which influence on the cementing quality with the method of experiment comparison. Measures were taken to improve the bonding quality through optimization of cementing method, mud performance and cement slurry. Based on the grain composition theory, cement additives were changed to improve the cement performance. By enhancing the gas migration control of cement slurry, excellent performance of slurry was achieved. Cement slurry test procedure were rearranged to eliminate the influence of mixing energy. To improve the displacement, the drilling fluid was optimized to get a stable and regular borehole. Cementing operation was developed and excellent bonding quality achieved.