Seismic velocities in rocks at ultrasonic frequencies depend not only on the degree of saturation but also on the distribution of the fluid phase at various scales within the pore space. Two scales of saturation heterogeneity are important: (1) saturation differences between thin compliant pores and larger stiffer pores, and (2) differences between saturated patches and undersaturated patches a...

Abstract: This article aims to study the effects of shock-disturbed cracks on the cutting features of cone bits. By utilizing the Walsh’s model, a crack model was established for the damaged rock surrounding the induced hole, the intrusive coefficient of the cone bit was derived, and the drilling rate equation around the induced hole was formulated. The effects of crack density and disturbance ...

Conductivity optimization is important for hydraulic fracturing due to its key roles in determining fractured well productivity. Proppant embedment is an important mechanism that could cause a remarkable reduction in fracture width and, thus, damage the fracture conductivity. In this work a new analytical model, based on contact mechanics and the Carman–Kozeny model, is developed to calculate t...

In this work, density functional theory within the framework of generalized gradient approximation has been used to investigate the structural, elastic, mechanical, and phonon properties of lutetium monopnictides in rock-salt crystal structure. The spin orbit coupling and Hubbard-U corrections are included to correctly predict the essential properties of these compounds. The elastic constants, ...

New velocity data in addition to literature data derived from sonic log, seismic, and laboratory measurements are analyzed for elastic silicate rocks. These data demonstrate simple systematic relationships between compressional and shear wave velocities. For water-saturated elastic silicate rocks, shear wave velocity is approximately linearly related to compressional wave velocity and the compr...

Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression tes...

Freeze-thaw damage of rocks is one significant natural causes for geo-hazards such as collapse and rockfall in alpine areas. To explore evolution granite a freeze-thaw environment, specimens Nyingchi Prefecture, Tibet, China were collected research objects. Saturated dry rock subjected to cyclic tests 0, 36, 72, 144 cycles the was analyzed by combining computed tomography (CT) scanning three-di...

The subject of this thesis forms part of a research program dealing with fractured rock masses being undertaken by the "Centre de Géologie de l'Ingénieur (CGI)" from the "Ecole Nationale Supérieure des Mines de Paris (ENSMP)" and the "Ecole Nationale des Ponts et Chaussées (ENPC)". In fractured rock masses, it is very difficult to undertake engineering works without analysing, beforehand, the f...

[1] The role of bedrock fractures and rock mass strength is often considered a primary influence on the efficiency of surface processes and the morphology of landscapes. Quantifying bedrock characteristics at hillslope scales, however, has proven difficult. Here, we present a new field‐based method for quantifying the depth and apparent density of bedrock fractures within the shallow subsurface...