3D printing has emerged as a valuable tool for studying the mechanical behavior of rock replicas under various stress−strain states. This technique enables the creation of an unlimited number of replicas with predetermined properties and a homogeneous structure. Among various 3D printing methods, liquid crystal display (LCD)-based printing offers a cost-effective and high-quality approach for rapid prototyping of rock samples. This study investigates the feasibility of using 3D LCD printing to create rock analogs for geomechanical investigations. We evaluate the microstructure of LCD-printed samples and its influence on their elastic and mechanical properties. To assess these properties, we subjected cylindrical samples to elastic wave propagation and uniaxial compression tests. Our results demonstrate that LCD-printed samples exhibit high homogeneity of elastic properties. The velocities of elastic wave propagation across and along the layers are essentially identical, differing only by the error value. Moreover, Young's moduli obtained under uniaxial loading are in good agreement with non-destructive test results, indicating a high degree of homogeneity in elastic properties up to 20 MPa. These findings suggest that 3D LCD-printed rock analogs are well-suited for investigating processes in rocks under purely elastic loading. Additionally, the technology's versatility allows for the creation of rock replicas with various features, providing researchers with the ability to study the mechanical behavior of rocks with specific characteristics. We demonstrate the potential of 3D LCD-printed rock analogs through a case study investigating the impact of cyclic deformations on the conductivity of thin capillaries in a porous medium. Our results provide a strong foundation for utilizing 3D LCD printing to advance our understanding of geomechanical processes in rocks.

This study investigates the causes of permeability decline in porous reservoirs under decreasing reservoir pressure by comparing laboratory experiments with well test data. Well tests indicate a greater sensitivity of permeability to pressure changes in reservoir formations compared to laboratory conditions and for this remain unclear. Field studies of permeability changes in northern Perm oil fields were conducted alongside laboratory experiments on core permeability under pressure. Results showed that highly permeable samples exhibited the greatest decline in permeability during elastic deformations, with reductions of 6% for limestones and 20% for sandstones. The relationship between permeability and purely elastic deformations for both rock types was accurately described by a power law. By comparing coefficients from field and lab studies, the mechanism of permeability decline in field conditions was established. A model incorporating elastic and plastic deformations of porous reservoirs was developed. The model considers the localization of plastic deformations in horizontal and vertical low-permeability deformation bands. Findings indicate that highly permeable formations are more susceptible to deformation band formation, particularly in thicker layers. The decrease in permeability was found to correlate strongly with the formation thickness, likely due to the formation of transverse deformation bands in pore layers.