Effect of Shale Reservoir Characteristics on Shale Oil Movability in the Lower Third Member of the Shahejie Formation, Zhanhua Sag

作者：Chuanxiang Ning, Zhongliang Ma, Zhenxue Jiang, Siyuan Su, Tingwei Li, Lunju Zheng, Guozhen Wang, Fengxun Li · 发表于：Acta Geologica Sinica - English Edition · 年份：2019 · DOI：10.1111/1755-6724.14284 · 被引用次数：20 · 研究领域：Hydrocarbon exploration and reservoir analysis、NMR spectroscopy and applications、Hydraulic Fracturing and Reservoir Analysis

Abstract To reveal the effect of shale reservoir characteristics on the movability of shale oil and its action mechanism in the lower third member of the Shahejie Formation (E s 3 l ), samples with different features were selected and analyzed using N 2 adsorption, high‐pressure mercury injection capillary pressure (MICP), nuclear magnetic resonance (NMR), high‐speed centrifugation, and displacement image techniques. The results show that shale pore structure characteristics control shale oil movability directly. Movable oil saturation has a positive relationship with pore volume for radius > 2 μm, as larger pores often have higher movable oil saturation, indicating that movable oil is present in relatively larger pores. The main reasons for this are as follows. The relatively smaller pores often have oil‐wetting properties because of organic matter, which has an unfavorable effect on the flow of oil, while the relatively larger pores are often wetted by water, which is helpful to shale oil movability. The rich surface provided by the relatively smaller pores is beneficial to the adsorption of immovable oil. Meanwhile, the relatively larger pores create significant pore volume for movable oil. Moreover, the larger pores often have good pore connectivity. Pores and fractures are interconnected to form a complex fracture network, which provides a good permeability channel for shale oil flow. The smaller pores are mostly distributed separately; thus, they are not conducive to...