A multi-continuum model for simulating in-situ conversion process in low-medium maturity shale oil reservoir

In-situ conversion is proposed applicable for low-medium maturity shale oil reservoir. However, parallel chemical kinetic reactions and evolution of shale pores during in-situ conversion make the numerical simulation a challenging problem. Although shale is typical multiscale and heterogeneous media, few models in previous studies take the difference between organic and inorganic system into consideration, which cannot simulate fluid flow accurately. In this paper, a multi-continuum model, considering coupled thermalreactive compositional flow, is developed to simulate in-situ conversion process in lowmedium maturity shale oil reservoir. The reaction of kerogen and hydrocarbon is quantified using kinetic reaction model. The evolution of fluid composition and shale properties are also incorporated. The accuracy of multiple-interacting-continua model and compositional model are demonstrated by comparing with commercial software and analytical solution. Then, the typical hexagon vertical well heating pattern is simulated and the feasibility is evaluated from an economic aspect. Finally, a series of case studies are conducted to investigate the impact of operation parameters on shale oil production.

Automated summary

This paper proposes a multi-continuum model considering coupled thermal-reactive compositional flow to simulate the in-situ conversion process in low-medium maturity shale oil reservoir. The accuracy of the multiple-interacting-continua model and compositional model is demonstrated and the impact of operation parameters on shale oil production is investigated through a series of case studies.