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非均质油藏各层的渗透率和孔隙结构不同,当有效压力变化时每一层的渗透率压敏性也不同,这必然会影响注入流体的分布。利用并联岩心模型,对低渗透非均质油藏的CO2驱开发过程进行了研究,分别讨论了渗透率和渗透率级差与有效压力的关系以及有效压力对流体分布的影响。研究结果表明,有效压力变化后,不同渗透率的岩心其渗透率压敏性不同,低渗透岩心渗透率压敏性比高渗透岩心的强;有效压力增加,渗透率级差变大,非均质性增强,高渗透岩心中分流率增加,低渗透岩心中分流率减少,波及体积减小。因此,在低渗透非均质油藏开发过程中应该保持合理的地层压力,尽量避免因压敏性而导致的波及体积减小的现象。
The permeability and pore structure of heterogeneous reservoirs are different. When the effective pressure changes, the permeability and pressure sensitivity of each layer are also different, which will inevitably affect the distribution of injected fluid. Based on the parallel core model, the development of CO2 flooding in low-permeability heterogeneous reservoirs was studied. The relationship between permeability and permeability difference and effective pressure and the effect of effective pressure on fluid distribution were discussed. The results show that the permeability of core with different permeability has different pressure-sensitivity when the effective pressure changes, the permeability of low-permeability core is more sensitive than that of high-permeability core; the effective pressure increases, the permeability difference becomes larger and the heterogeneity Sexually enhanced, high-permeability cores in the diversion rate increased, low-permeability cores to reduce the shunt rate, affecting the volume decreases. Therefore, in the development of low-permeability heterogeneous reservoirs, reasonable formation pressure should be maintained to avoid the volume-reducing phenomenon caused by pressure-sensitivity.