Table 1 Results obtained by experts and scholars using different software to study various problems.

Sun et al.¹⁷

Ansys

Numerical simulation and optimization study of In-Situ Heating for three-dimensional oil shale exploitation with different well patterns

In the whole in-situ heating process of oil shale, the well network model consisting of eight heating wells and one production well with adjacent heating wells connected to the production well at an angle of 45° has the lowest power consumption per unit volume of 814.8 kWh. The power consumption was the lowest at 814.87 Kw/m³ and the energy utilization efficiency was the highest. This is a significant reduction of 41.93% in power consumption per unit volume compared to the other six well network models. This is a significant 41.93% reduction in power consumption per unit volume compared to the other six well network models

Jia et al.¹⁸

COMSOL

Thermo-hydro-mechanical coupling in oil shale: Investigating permeability and heat transfer under high-temperature steam injection

The study integrates theoretical analysis and numerical simulations to uncover the fundamental connections between internal permeability and heat transfer mechanisms during steam injection. It reveals that oil shale undergoes two critical evolutionary phases: a stability phase below 350 °C, where volatile dispersion occurs, and a rapid increase phase above 350 °C, marked by significant microstructural changes from micro-fractures to extensive through-going fractures due to intense thermal decomposition. This decomposition leads to increased gas production and enhanced thermal fracturing. The threshold temperature is identified at 400 °C, above which the oil shale’s mechanical strength and pore pressure increase, leading to decreased volumetric compression until stabilization

Sun et al.¹⁹

Fluent

Numerical study on enhanced heat transfer of downhole slotted-type heaters for in situ oil shale exploitation

Numerical studies are conducted on the heat transfer performance and shell-side fluid flow characteristics of a perforated plate-type heater. The variations of the heat transfer factor N_u, friction factor f, and evaluation parameter N_u/f^1/3 are analyzed for different helix angles β and ratios of the long and short semiaxes of the circular holes on the heating plate under different Reynolds numbers R_e. The results reveal that under the same shell-side Reynolds number R_e, the heat transfer factor N_u shows an increasing trend with the increase in the proportion of the helix angle β

Chen et al.²⁰

CMG

An effective numerical simulation method for steam injection assisted in situ recovery of oil shale

An effective numerical simulation method is proposed for production prediction of in-situ recovery from steam-injected oil shale reservoirs. In this method, a finite volume based discretization scheme for the heat and mass transfer equations of the thermal constitutive model is derived and used. An embedded discrete fracture model is used to accurately treat fractured vertical wells. A smooth nonlinear solver is proposed to solve the global equations, and then cell pressure, temperature, saturation, component mole fraction and well productivity can be obtained

Yang et al.²¹

CMG

Numerical simulation of the development effect of oil shale autogenous thermal in-situ conversion in straight and horizontal wells

Taking oil shale in Xunyi area of Ordos Basin as the research object, numerical simulation method was used to compare the development effect of oil shale autogenous thermal in-situ transformation between straight wells and horizontal wells, and the difference in the development effect of oil shale autogenous thermal in-situ transformation between straight wells and horizontal wells was investigated

Zhang et al.²²

COMSOL

Simulation of in-situ steam-driven oil seepage in single-fracture oil shale CT digital cores after pyrolysis at different temperatures

Based on the digital cores of oil shale obtained from high-temperature steam in-situ pyrolysis and micro-CT scanning experiments, the real structure of oil shale after pyrolysis at different temperatures is seamlessly integrated into COMSOL through precise grid division, and it is concluded that the degree of development of the pore structure and the connectivity has a significant impact on the advancement speed of the phase interface—the better the degree of development of the pore structure, the faster the advancement speed of the phase interface

He²³

Fluent

Near-critical water in-situ oil shale extraction

The heating effect of unidirectional heat injection could be better. The simulation results of temperature field, asphalt extraction rate, and porosity show that the oil shale layer can be heated to the desired temperature faster by intermittently switching heat injection wells and production wells. The desired heating effect and asphalt extraction rate can be obtained after 80 days of heating by changing the heat injection wells and the production wells once every 30 days

Zhu²⁴

COMSOL

Three-dimensional numerical simulation on the thermal response of oil shale subjected to microwave heating

The influence of microwave frequency and power on the temperature distribution of oil shale sample is investigated. The results reveal that the temperature distribution of oil shale sample is not uniform under microwave heating due to the nonuniform distribution of electric field. Microwave heating is most efficient at a frequency of 2.45 GHz because of the size and shape of rectangular waveguide. The temperature rise of oil shale is characterized by “slow-fast”, because the dielectric property of oil shale is temperature-dependent

Wang²⁵

COMSOL

Anisotropic evolution of thermophysical, seepage, and mechanical characteristics of oil shale under high temperatures

The temperature field distribution of the oil shale reservoir is closely related to the transportation of superheated vapor in the reservoir, and a zone of rapid temperature decrease is formed at the edge of the temperature field; the factor that has the greatest influence on the oil and gas production is the anisotropy of the seepage rate, followed by the anisotropy of the mechanical parameter. The anisotropy of each of the heat transfer coefficients does not have much influence on the oil and gas production

Zhao²⁶

COMSOL

Study on the mechanical properties of oil shale pyrolysis and percolation law under the action of microwave

The size of microwave power affects the heating rate, the change of reservoir temperature field is closely related to the microwave pyrolysis time, the permeability inside the reservoir increases with the increase of microwave pyrolysis time, and the rise of reservoir porosity promotes the oil and gas seepage. The reservoir will produce larger displacement under high power. Comprehensively, 600 W is the most suitable power under three kinds of power