Numerical simulation of remaining oil distribution in tight sandstone reservoirs: a case study of the upper Triassic Yanchang formation in the Ordos Basin, China

• Published in: Arabian journal of geosciences Vol. 14; no. 1
• Main Authors: Li, Airong, Qiang, Qian, Yin, Shuai, Zhang, Jingong, Wu, Fuli, Yin, Ning
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 2021; Springer Nature B.V
• Subjects: Distribution; Earth and Environmental Science; Earth science; Earth Sciences; Life cycle; Life cycles; Mathematical models; Nose; Oil; Oil and gas fields; Oil field equipment; Oil fields; Oil production; Oil recovery; Original Paper; Properties; Properties (attributes); Sand; Sandstone; Saturation; Sedimentary facies; Sedimentary rocks; Simulation; Thickness; Triassic; Ordos Basin; Remaining oil saturation; Density of the well pattern; Zichang oilfield; Yanchang formation; Tight sandstone reservoir
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-020-06325-3

In order to improve the recovery of tight oil and extend the life cycle of the oilfield, in this paper, we have conducted a systematic study on the fine characterization of remaining oil distribution. A three-dimensional numerical simulation method was used to study remaining oil distribution of tight sandstones with the constraints of structure, sedimentary facies, and petrophysical properties. The results show that the distribution of remaining oil in the Chang 2 Member was affected by the structural location, sand body thickness, and petrophysical properties. The remaining oil saturation is higher in the axial parts of nose-like uplifts, the edge parts of thick sand bodies, and the positions where the monoclinic and sand bodies intersect; however, in the flanks of the nose-like uplifts, when the monoclinics are distributed nearly parallel the sand bodies, and in low-lying areas, a low oil saturation distribution often occurs. When two parameters in structure, sand body thickness, and petrophysical properties satisfy favorable conditions, this area is likely to become a favorable remaining oil enrichment area. Numerical simulation results show that improving the injection and production well pattern and increasing the number of oil production wells are important measures to improve oil recovery. The density of the well pattern can be considered as 30–50 wells per square kilometer.