Multiscale Experimental Characterization and FDEM Integration of Deformation and Failure of Deep Mudstone Under High Temperature and High Pressure
Year: 2026
Type: article
Abstract: The deformation and failure mechanism of deep mudstone under high temperature and high pressure (HTHP) is a critical issue constraining deep-drilling efficiency. Taking an HTHP mudstone formation in the western South China Sea as the research object, this study integrates X-ray diffraction, scanning electron microscopy, nanoindentation, HTHP triaxial compression tests, and FDEM numerical modeling incorporating mineral heterogeneity and Weibull strength distribution. The mudstone is predominantly composed of clay minerals (44.67%) and quartz (32.37%), with low hardness (1.42–2.96 GPa) and moderate elastic modulus (43.9–58.2 GPa). Under ambient conditions, uniaxial compressive strength is approximately 19.5 MPa with axial splitting failure; at 40 MPa confining pressure, strength increases to 121.8 MPa with shear failure; at 150 °C and 40 MPa, peak strength slightly decreases, yield point is delayed, and post-peak decline accelerates. The FDEM model, calibrated against experimental data, reasonably reproduces crack evolution and failure modes. However, due to limited tests (one per condition) and variations in specimen depth, statistical robustness is constrained; thus, this study does not yet establish a generalizable quantitative cross-scale correlation, and the findings are primarily applicable to the specific formation investigated.
Source: Applied Sciences
DOI: 10.3390/app16178420
Authors: Haodong Chen, Yan Jin, Hongda Li, Maozhu Li, Yunhu Lu
Institution: China University of Petroleum, Beijing
Language: English
Topic: Rock Mechanics and Modeling
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,896
Award: G452235642
OpenAlex ID: W7204107091