Molecular modeling on Gulong shale oil and wettability of reservoir matrix

Abstract

Understanding molecular interactions between oil and reservoir matrix is crucial to develop a productive strategy for enhanced oil recovery. Molecular dynamics simulation has become an important method for analyzing microscopic mechanisms of some static properties and dynamic processes. However, molecular modeling of shale oil and reservoir matrix is still challenging, due to their complex features. Wettability, which is the measurement of oilmatrix interactions, requires in-depth understanding from the microscopic perspective. In this study, the density, interfacial tension and viscosity of eleven common components in shale oil are calculated using molecular dynamics simulations. Then a molecular model of Gulong shale oil is built, based on the reported experimental results and simulations. Compared with the variation in hydrocarbon content, the change in polar component content leads to more significant variations in the physical properties of shale oil. This molecular model is also employed to investigate the wettability of shale-oil nanodroplets on minerals and organic matter, with or without the surrounding aqueous phase. This work suggests fresh ideas for studying the oil-matrix interactions on the nanoscale and provides theoretical guidance for shale oil exploitation.

Multi-Scale and Multi-Dimensional Imaging of Mineral Matrix Pore-Fracture Networks in Lower-Thermal-Maturity Lacustrine Shale: Examples from the Paleogene Shahejie Formation, Bohai Bay Basin

“…Inorganic pores and fractures are dominantly significant in the shale oil generation window, and organic pores are significant in the shale gas generation window. Several investigations have been performed on the role of the mineral-hosted pore-fracture network and microscopic mechanism of the liquid hydrocarbon storage in these in lower-thermal-maturity, lacustrine shale. ,,− Recently, it has been shown that inorganic minerals can host abundant pore-fracture networks during deposition to burial as overburden stress and diagenesis increase . Loucks et al suggested that rigid mineral particle skeleton support, mechanical compaction, and later dissolution strongly control the inorganic pore-fracture formation and development.…”

Wetting Behavior of Kerogen Surfaces: Insights from Molecular Dynamics

“…To bridge our understanding of the intricacies of wetting phenomena with the molecular-level nuances, molecular dynamics (MD) simulations have emerged as an indispensable tool. − Most MD simulations, nevertheless, have primarily focused on homogeneous and smooth surfaces such as graphene and graphite, , but these do not properly represent kerogen’s heterogeneous and rough nature. , To gain deeper insights into wettability, recent studies have started to employ more realistic models of kerogen in which wettability is described by the wetting contact angle of the fluid on the kerogen surface (Table ).…”

Current Status and Future Trends of In Situ Catalytic Upgrading of Extra Heavy Oil

“…The increase in demand and consumption of light crude oil has led to a decline in global oil reserves and supply. Therefore, short-term and long-term demand needs to be supplemented by unconventional oil resources [1][2][3][4][5][6][7][8]. Heavy oil resources are widely spread around the world.…”