特低渗凝析气藏复合解堵技术应用

Composite plug removal technology for ultra-low permeability condensate gas reservoir

针对特低渗凝析气藏修井过程中压井液、水凝胶大量漏失导致产量骤减这一实际生产情况,通过压井液水凝胶性能评价、水凝胶老化实验,定量分析其对储层造成的伤害程度。结合修井作业特征及储层潜在伤害因素,总结储层伤害原因并借鉴前人复合解堵经验,通过单剂优选及复配实验,研制出一套复合解堵体系。通过室内实验和现场应用,对由修井液大量漏失造成的水凝胶固相堵塞以及修井液和凝析油造成的液相伤害具有显著的解堵效果,对目标区块类似井的解堵增产具有直接的借鉴意义。

During the workover operation, the gas production in the actual production condition plummets due to the poor plugging performance and mass loss of the well killing fluid and the hydrogel. The quantitative analysis was conducted on the degree of damage of the reservoir by evaluating the physicochemical property of well killing fluid and hydrogel as well as performing hydrogel aging test and core flow experiments. Combined the workover job characteristics with the potential damage factors of the reservoir, and by summarizing the main damage factor and based on the experience of the predecessors, a composite plug removal fluid system was developed including acid and non-acid composition. A series of core flow experiments and field applications had proved that the fluid system had a significant plug removal effect, which could provide some direct guidance to the similar wells in the target block.