Abstract: Honghe oilfield is a typical ultra⁃low porosity and tight oil reservoir, and it is difficult to use conventional water injection development method economically and effectively. By using indoor physical simulation experiments, the feasibility of CO₂ flooding method in Honghe oilfield was explored from the aspects of compatibility of CO₂ with crude oil and reservoirs, formations injection capacity and reservoir injection limits. The results show that CO₂ fluids injection in the reservoirs of Honghe oilfield does not block and the compatibility of CO₂ with reservoir crude oil is good. Under the same permeability, the CO₂ flooding injection index is 8 times of the water injection index, and the CO₂ injection is a relatively stable process. The breakthrough time of CO₂ injection is relatively longer than N₂ injection. At the lower permeability stage, there is no rapid breakthrough; combined with non⁃linear percolation and constant⁃velocity mercury injection experiment technology, we find pressure gradient of CO₂ injection is obviously increased when the permeability is lower than 0.08 mD. It is determined that 0.08 mD is the lower limit of reservoir permeability for CO₂ injection. The comprehensive experimental results show that the development of CO₂ injection in the Honghe tight reservoir is technically feasible.

Key words: Honghe oilfield, Tight oil reservoir, CO₂ fooding, Physical simulation experiments, Technological limits

摘要： 红河油田是典型的特低孔致密油藏，采用常规注水开发方式难以经济有效动用。采用室内物理模拟实验手段，从CO₂与储层和地层原油的配伍性、注入能力及储层注入界限等方面，探讨了红河油田注CO₂开发的可行性。实验结果表明，红河油田储层注CO₂流体不会产生堵塞，CO₂与储层原油配伍性较好；相同渗透率下，CO₂驱的注入指数为注水指数的8倍，且注CO₂驱是一个比较稳定的过程，注CO₂驱相对注N₂驱来说，突破的时间较长，在较低渗透率的时候，没有出现较快突破的情况；结合非线性渗流、恒速压汞实验技术，发现当渗透率低于0.08 mD时，注CO₂的压力梯度呈明显升高的趋势，确定0.08 mD是注CO2驱的储层渗透率下限。综合实验结果表明，红河致密油藏注CO₂驱开发在技术上是可行的。

关键词: 红河油田, 致密油藏, 注CO₂开发, 物理模拟实验, 技术界限