Well Configuration Optimisation for In Situ Thermal Upgrading Towards Low‐Maturity Oil Shales From Songliao Basin ( NE China) With Perspectives on CO ₂ Geo‐Sequestration

In situ heating is a promising technique for pyrolyzing organic matter within low‐maturity oil shales to enhance hydrocarbon recovery. This work establishes a thermal‐hydro‐mechanical (THM) coupled model to optimize well configurations for the Upper Cretaceous Qingshankou Formation in Songliao Basin (NE China). Integrating anisotropic thermophysical parameters from core experiments (1110–1130 m depth) and field data, we systematically compare six well patterns (three vertical, three horizontal) under a 3‐year heating period, evaluating 20 and 30 m well spacings for dual‐well setups. A key finding is the pronounced anisotropy in heat propagation, where horizontal transport along bedding planes is approximately 3.2 times faster than vertical transfer, fundamentally controlling the fluid flow and thermal coverage. Results demonstrate that a well spacing of 30 m maximizes the pyrolysis area for both well types, yielding effective heating areas of 1640 m 2 (vertical) and 540 m 2 (horizontal). Beyond guiding field operations for hydrocarbon recovery, the thermophysical framework provides critical insights for CO 2 geo‐sequestration, suggesting that the managed anisotropic heat‐fluid flow can enhance injectivity and trapping security in analogous layered basins.