常规天然气分析标准对页岩气的适应性评价研究

针对川西地区中浅层长水平井钻进过程中存在的水平井段长易卡阻、砂岩泥岩交错易发生井壁失稳等难题,研制出了新型聚胺仿油基钻井液。该钻井液主要由具有强抑制作用的处理剂聚胺和主要作用为润滑和降滤失、兼具抑制功能的处理剂MEG(甲基葡萄糖甙)组成,具有高润滑性和强抑制性的特点,其抑制性能和润滑性能接近油基钻井液水平。现场应用表明,聚胺仿油基钻井液性能稳定、密度调节范围广、流变易于控制、滤失量小且泥饼薄而韧性好,能有效地抑制泥页岩水化分散,保持井壁稳定,满足川西长水平井段施工需求。

An applicability evaluation research on conventional gas analysis standards applied to shale gas

For easy jamming of the horizontal section of shallow long horizontal well drilling in the western Sichuan region, or sandstone and mudstone interlaced prone to borehole instability and other problems, a novel polyamine imitation oil-based drilling fluid was studied. The drilling fluid is mainly composed of polyamine with strong inhibiting effect and MEG （methyl glucoside） with the primary role of lubrication, lowering filtrate and inhibiting function. The drilling fluid has high lubricating property and strong inhibitory, and the performances of evaluation system approach the level of oil-based drilling fluid. Field application shows that polyamine imitation oil- based drilling fluid has the advantages such as stability performance, a wide range of density reg- ulation, theological easy to control, small amount of fluid loss and the thin cake, good-tough- ness, effectively inhibiting shale hydration dispersed, and maintaining the borehole wall stable. Thus, the drilling fluid meets the requirements of the long horizontal section construction needg in western Sichuan.