致密储集层补充能量方式分选及其界限

Study on Energy Replenishment Mode Selection and Its Limit in Tight Oil Reservoirs

致密储集层孔喉狭小,流固耦合作用明显,各致密储集层产区注水及注气驱替技术实施效果迥异,分选合理补充能量方式是当前致密油生产上面临的难题。利用数值模拟方法开展致密储集层水平井分段压裂不同补充能量方式的生产效果研究,探讨分选补充能量方式的主控因素,并提出明确界限。研究表明,渗透率的差异是分选补充能量方式的关键。相较于孔隙半径,喉道半径对渗透率的影响较高,直接影响着致密油藏的动用程度和开发效果,同时反映储集层的微观特征,可作为致密储集层补充能量方式的分选参数。研究认为,可将主体喉道半径1.5μm作为致密油储集层补充能量方式的分选界限。

The pore throats are narrow and fluid-solid coupling is obvious in tight reservoirs. Because the implementation results of water-flooding and gas drive are very different in different tight reservoir blocks, selecting reasonable energy replenishment modes is a difficultproblem in tight oil production. The paper uses numerical simulation methods to study the effects of different energy replenishment modesfor staged fracturing in tight reservoirs in horizontal wells, discusses the main controlling factors of the energy replenishment mode selec-tion and proposes definite limits. The study shows that the difference of permeability is the key parameter to select energy replenishmentmode. Compared with pore radius, pore throat radius has more impacts on permeability, which can influence the producing degree and de-velopment effect of tight oil reservoirs directly, and meanwhile, can reflect microscopic characteristics of the reservoirs, so it can be a pa-rameter for energy replenishment mode selection. It is considered that the main pore throat radius of 1.5 μm can be used as the limit for en-ergy replenishment mode selection in tight oil reservoirs.