注水开发后期河流相储层流动单元特征

在利用岩心资料划分流动单元的基础上,用岩心刻度测井资料建立了流动单元储层参数评价模型。利用该模型对储层空间流动单元进行划分和综合研究,结果表明,根据流动单元的渗流特征、储层质量、渗流能力及沉积微相等方面的特征,可将流动单元划分为7种类型。流动单元空间分布主要受沉积微相控制,剩余油主要分布于流动能力中等的Ⅴ—Ⅶ类流动单元中。在开发过程中,由于不同流动单元的变化程度不同,使不同流动单元之间的渗流能力相差较大。该研究结果揭示了在注水开发过程中高孔、高渗疏松砂岩储层不同流动单元的变化特征以及流动单元对微裂缝的形成、剩余油富集规律的控制作用,为高含水时期油田的控水稳油方案的制定提供了依据。

Characteristics of flow unit in fluvial reservoir with high water cut

Based on the division of flow units with core data of fluvial reservoir, a model for evaluating reservoir parameters was established by using logging data obtained from flow unit constraining and core calibrating. The flow units of fluvial reservoir were classified and studied comprehensively by using the evaluation model. The results show that flow units can be divided into seven types according to characteristics of fluid flow in porous medium, reservoir property, fluid flow capacity through porous medium and sedimentary microfacies of the flow units. The distribution of flow units is controlled by sedimentary microfacies. The remaining oil mainly distributes in the fifth, sixth and seventh units with the medium permeability. Because different flow units have different variables during reservoir development, the flow capacities of fluid in porous medium for different flow units are greatly different. The variable characteristics of different flow units of unconsolidated sandstone reservoir with high porosity and high permeability in the late stage of water flooding development and the effects of flow units on the formation of microfissure and the accumulation of remaining oil were investigated. These results provide an important basis for controlling water cut to stabilize oil production in the stage of high water cut.