硅酸盐钻井液的储层保护技术研究

Reservoir prevention technology of silicate drilling fluid

硅酸盐钻井液对储层的不可逆严重损害是影响其推广应用的主要因素。通过硅酸盐、无机盐、土粉、加重剂和pH值对储层损害的影响分析认为,硅酸盐与钻井液中的金属离子生成不易酸化的多元复合沉淀及溶胶(凝胶)堵塞油气通道是造成储层损害的主要原因。对硅酸钻井液的储层保护技术进行探索,并提出以替换、稀化、缓释、屏蔽、溶解等技术措施提高储层渗透率恢复值,解决硅酸盐钻井液储层保护能力不足的问题,促进硅酸盐钻井液体系的推广应用。

Through analyzing the merits and shortcomings of silicate drilling fluid,it is thought that the serious reservoir damage is the main bottleneck problem. This paper analyzes the influence factors of silicate adding, inorganic salt, bentonite, barite and PH on formation. The result shows that the silicate and metals ion in drilling fluid can generate diverse composite precipitating gum/gel, which can plug the oil and gas passage. The technology of formation damage prevention for silicate drilling fluid is developed and the technology measures as replacement, dilution, releasing, shielding and solution are put forward in order to improve the permeability buiht-up value, resolve the problem on drilling fluid prevention and expand the application of silicate drilling fluid.