Evolutionary mechanisms of pore-fracture network development in oil shale during pyrolysis: current research progress and perspectives

Abstract

Efficient heat transfer, enhanced pyrolysis performance, and effective hydrocarbon migration are essential for the successful application of oil shale in situ conversion technology. However, under natural conditions, oil shale exhibits low thermal conductivity and is nearly impermeable. Pores and fractures within the rock act as critical channels for both heat transmission and hydrocarbon flow. Thus, understanding their evolution during pyrolysis is essential. This review consolidates experimental characterization techniques for pore and fracture structures and investigates their dynamic behavior under varying conditions. The influences of temperature, pressure, organic content, heating strategy, mineral composition, and bedding structure are systematically analyzed. Additionally, future research directions are proposed. The findings aim to provide valuable references for the design and implementation of oil shale in situ conversion technology.