STJ植物胶冲洗液滤饼强化研究

Study on filter cake strengthening of STJ plant gum drilling fluid

摘要:

复杂破碎地层钻进时常出现孔壁坍塌等问题，为了防止此类事故发生，提高岩心采取率，常采用绳索取心钻进，需要使用防塌性能强的无固相冲洗液。STJ植物胶冲洗液为环保型无固相冲洗液，但其形成的滤饼稀疏，不足以满足护壁需要。本文针对STJ植物胶冲洗液滤饼稀疏这一问题，以STJ植物胶冲洗液为基础，结合理想充填理论，采用室内实验、微观分析等研究手段，优选填充材料并优化配比，研究植物胶冲洗液的滤饼强化机理。实验研究表明，由2% STJ+3% YT-1+2% YT-2+3% YT-3配制成的无固相冲洗液滤失量显著降低，其形成的滤饼更为致密平坦，护壁性能大幅提升。微米级填充材料通过颗粒级配形成致密滤饼，符合理想充填理论，为复杂地层钻进提供了环保高效的解决方案。

Abstract:

Borehole wall collapse and other issues frequently occur during drilling in complex fractured formations. To prevent such accidents and improve core recovery， wireline coring drilling is commonly used， which requires solid-free drilling fluids with excellent anti-collapse performance. The STJ plant gum drilling fluid is an environmentally friendly solid-free drilling fluid； however， the filter cake formed by it is sparse， which fails to meet the requirements of borehole wall protection. Aiming at the problem of sparse filter cake of the STJ plant gum drilling fluid， this study took the STJ plant gum drilling fluid as the base fluid， combined with the ideal packing theory， and employed research methods such as laboratory experiments and microscopic analysis to optimize the selection of filling materials and their proportions， as well as to investigate the filter cake strengthening mechanism of the plant gum drilling fluid. Experimental results indicate that the solid-free drilling fluid formulated with 2% STJ+3% YT-1+2% YT-2+3% YT-3 exhibits a significant reduction in filtration loss. The filter cake formed by this drilling fluid is denser and flatter， and its borehole wall protection performance is greatly enhanced. Micron-sized filling materials form a dense filter cake through particle gradation， which is consistent with the ideal packing theory. This research provides an environmentally friendly and efficient solution for drilling in complex formations.