Porous geomaterials, such as oil and gas reservoir rocks (sandstone, carbonate rocks, shale), are naturally heterogeneous, multi-phase solids with disordered microstructures spanning multiple length scales, from nanoscale grain contacts and micro/nano-pores to kilometre-scale fracture networks and reservoir architectures. They represent one of the most mechanically complex material systems in nature and serve as a core research subject in petroleum geology and reservoir engineering. Under in-situ conditions of high temperature and high pressure in deep hydrocarbon reservoirs, the mechanical behaviour of these materials involves pressure-dependent yielding, thermally activated creep, and strong nonlinear coupling among deformation, pore fluid pressure, and temperature fields. These processes directly govern critical engineering problems such as borehole wall stability, reservoir compaction and sand production, and formation response during thermal recovery. When fractures propagate through reservoir media containing pre-existing discontinuities (natural fractures, bedding planes, etc.), the process is dominated by nonlinear fracture mechanics and accompanied by pronounced material heterogeneity effects, which constitutes the central mechanical challenge in hydraulic fracturing and fractured reservoir evaluation. Meanwhile, frictional instability and slip dynamics along faults and fracture surfaces are closely linked to tribological and geomechanical issues in oil and gas field development, such as injection- and production-induced seismicity, fault reactivation, and caprock integrity assessment. These problems place porous geomaterials firmly at the frontier of solid mechanics, fracture mechanics, and materials science, and they directly serve geomechanical analysis and engineering design in hydrocarbon exploration and development.
Despite significant recent progress, several open challenges remain. The multi-scale nature of geomaterial mechanics, spanning from nanoscale grain-contact physics and chemo-mechanical effects at micro-pore surfaces to macroscopic constitutive response at the wellbore and reservoir scales, presents a central upscaling challenge that demands integrated experimental, theoretical, and computational approaches, in order to construct reliable cross-scale models from micro-scale rock physics to reservoir geomechanics. The mechanisms governing the transition from stable deformation to dynamic fracture instability in fluid-saturated porous media, such as reservoir rocks during hydraulic fracturing, have not been fully resolved, directly affecting the optimisation of hydraulic fracturing treatment parameters and the prediction of fracture network morphology. Under repeated stress perturbations from cyclic injection and production, cyclic gas injection, or re-fracturing, the fatigue and cyclic mechanical response of reservoir rocks requires more rigorous theoretical treatment, which has significant implications for wellbore integrity, long-term evolution of fracture conductivity, and ultimate recovery. Moreover, quantitative characterisation of dynamically evolving three-dimensional natural fracture networks and hydraulic fracture networks in heterogeneous reservoirs remains a major methodological challenge for high-resolution fractured reservoir modelling and unconventional oil and gas development.
This Research Topic brings together cutting-edge contributions in the mechanics of porous geomaterials, with an emphasis on research that bridges different length scales, links microstructural observations to macroscopic mechanical behaviour, or advances the theoretical treatment of coupled multi-physics processes in heterogeneous porous solids. We particularly encourage submissions that focus on geomechanical problems in hydrocarbon exploration and development, including, but not limited to, coupled multi-physics mechanics in processes such as unconventional reservoir stimulation, deepwater drilling, thermal recovery, and CO2 geological storage. Submitted papers must have porous geomaterials or rocks as their primary material subject of study. This Research Topic welcomes original research articles, reviews, methodological papers, and data reports. Topics of interest include, but are not limited to:
1. Multi-scale mechanical behaviour of geomaterials
2. Fluid-driven fracture propagation in porous media: mechanics, modelling, and experimental characterisation
3. Characterisation and evolution of stress state in fluid-saturated porous solids
4. Frictional instability and slip dynamics along discontinuities in geomaterials
5. Quantitative characterisation of natural fracture networks in heterogeneous porous media
6. Mechanical behaviour of geomaterials under extreme pressure and temperature conditions
7. Fatigue and cyclic mechanical response of porous geomaterials
8. Constitutive modelling and upscaling strategies for heterogeneous porous media
Article types and fees
This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:
Brief Research Report
Data Report
Editorial
FAIR² Data
Hypothesis and Theory
Methods
Mini Review
Opinion
Original Research
Articles that are accepted for publication by our external editors following rigorous peer review incur a publishing fee charged to Authors, institutions, or funders.
Article types
This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:
Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.
