High heat loss, substantial energy consumption, considerable CO₂ emission and low thermal utilization efficiency are main challenges in the thermal-based production methods applied in high viscous oil reservoir. To address these limitations while achieving both high oil recovery and reduced carbon footprint, this perspective systematically investigates an enhanced high viscous oil recovery method that integrates in-situ pyrolysis with downhole electric heater. Laboratory experiments and field applications demonstrate that this novel technology offers multiple advantages over conventional thermal-based methods, such as higher thermal utilization efficiency, lower carbon emissions and reduced energy consumption. In this novel technology, with high temperature in the reservoir, inducing pyrolysis and cracking reactions in high viscous oil, significantly reducing oil viscosity and enhancing oil recovery factor. Thereby, this novel method presents a viable, low-carbon, and efficient pathway for future development of high viscous oil resources.

This paper investigates the influence of reaction atmosphere and operation parameters of the lightening process under high temperature and high pressure on high-viscosity shale oil using an experimental approach. Two types of experiments were implemented, one involving a thermogravimetric analyzer and another using an autoclave to carry out the lightening process. By these two kinds of experiments, the effects of reaction atmosphere and operation parameters on the lightening efficiency were clarified. As for the reaction atmosphere, the effects of CO₂, N₂ and air were separately evaluated. As for the operation parameters, the effects of heating rate and formation rock were investigated. The results indicate that under a CO₂ atmosphere, the lightening reaction is more intense than that under the other two gas phases, and it gains the highest reaction rate. Part of the minerals in the formation rock can be treated as catalyst in the shale oil lightening process. With the formation rock being present, the reaction rate increases significantly and higher contents of light components are obtained in both the lightened shale oil and gas phase. For the kinetic parameters in the lightening process, proportional relationships between the kinetic parameters and heating rates under CO₂ atmosphere with and without formation rock were identified. The findings of this study can provide guidance for enhancing high-viscosity shale oil using an in-situ lightening process.