南堡2、3号构造带保护储层的钻井液体系

现有钻井液对南堡2、3号构造第三系储层损害主要为液相损害并且其封堵效果不佳,为了降低损害程度提高封堵效果,对研究区块的储层岩性、物性、敏感性和潜在损害因素等进行分析。利用FDY—Ⅱ型储层综合损害实验评价系统和钻井液高温高压封堵评价等方法进行钻井液优化设计。结果表明,优选后的钻井液体系表面张力由30. 61 m N·m-1降至27. 51 m N·m-1,防水锁能力提高;高温高压滤失量由22. 7 m L降至14. 2 m L,滤失量低且封堵效果明显;岩心渗透率恢复值由70%以下提高到85%以上。研究成果为南堡2、3号构造带致密油气藏勘探开发提供保护储层的钻井液体系备选方案。

Study on the Drilling Fluid System of the Protection Reservoir of Nanpu Tectonic Zone No.2 and Tectonic zone No.3

The existing drilling fluid damage to the tertiary reservoirs of No. 2 and No. 3 structures in Nanpu is mainly liquid phase damage and its blocking effect is not good. In order to reduce the degree of damage and improve the sealing effect, the reservoir lithology, physical properties, sensitivity and potential damage factors of the study block were analyzed. FDY-II reservoir comprehensive damage experimental evaluation system and drilling fluid high temperature and high pressure plugging evaluation were utilized to optimize the drilling fluid optimization. The results show that the surface tension of the optimized drilling fluid system is reduced from 30.61 mN·m-1 to 27.51 mN·m-1, and the waterproof lock capacity is improved. The high temperature and high pressure fluid loss is reduced from 22.7 mL to 14.2 mL, and the fluid loss is low. The plugging effect is obvious; The core permeability recovery value is increased from below 70% to over 85%. The research results provide an alternative to the drilling fluid system for the protection of reservoirs in the exploration and development of tight reservoirs in Nanpu No. 2 and No. 3 structural belts.