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Thermal conductivity is a key parameter for many soil applications, especially for dimensioning shallow and very shallow geothermal systems based on the possible heat extraction rate and for modelling heat transfer processes around high voltage underground cables. Due to the limited purview of direct thermal conductivity measurements, for an investigation of extensive areas, usually other geophysical

The brittleness of rocks plays an important role in the fracture network fracturing process of unconventional oil and gas reservoirs, the drilling efficiency of rock breaking and wall stability, and mining engineering. Rock brittleness has become one of the key parameters in the study of many rock mechanics and related engineering problems. However, there is still no widely accepted definition of brittleness

In the framework of a \({{\hbox {CO}}}_{2}\) storage feasibility study, we evaluate porosity and permeability of shale formations constituting the overburden of a hydrocarbon reservoir, where the gas is stored. These properties are required to perform fluid-flow simulations and analyze possible leakages from the reservoir to the surface. In this process, calibration with well logs is essential. Standard

Radial drilling hydraulic fracturing has become a new stimulation method. The hydraulic fracturing effect of radial drilling on site is not ideal, and the stimulation effect of some wells is not obvious. The hydraulic fracturing effect of radial drilling is closely related to the crack initiation position after radial drilling fracturing. In the past researches on fracture initiation in radial drilling

Geothermal resource quantification requires underground temperature and volume information, which can be challenging to accurately assess at the regional scale. The analytical solution for steady-state heat conduction with internal heat generation is often used to calculate temperature at depth, while geological models can provide volume information. Both approaches were originally combined in a single

To describe the mechanical behavior of interfaces existing in rocks, a three-dimensional contact element model with a certain thickness was proposed that could simultaneously consider the heterogeneity, damage evolution and state variation of interfaces. The Weibull distribution function was employed to describe the rock heterogeneity. The damage evolution of the contact element was analyzed by using

This study prepared transversely isotropic rock-like specimens in three groups of layer thickness ratios, alternating with two kinds of rock-like materials. The conventional triaxial compression tests confirm mechanical difference of the two rock-like materials. The velocities of ultrasonic wave (longitudinal wave VP) are measured for each transversely isotropic rock-like specimen before uniaxial compressive

With the development of deep energy resources, understanding variations in the physical and mechanical properties of rocks at different depths is significant. In this paper, core samples from ten different burial depths (1000 m, 1300 m, 1600 m, 1850 m, 2600 m, 3500 m, 4800 m, 5100 m, 5600 m, and 6400 m) were collected from the Songke No. 2 (SK-2) well and the Daqing Oilfield. To the best of our knowledge

Permeability and meso-structure evolution of coal are crucially important to the profound understanding of coal–gas interactions in the enhanced coalbed methane recovery and in controlling gas outburst. Very few studies focus on the effect time has on these interactions We performed a series of experiments on the permeability evolution of coking coal subjected to the long-term exposure of triaxial

Fluid flow through rock media is highly significant in underground water management, the geothermal recovery process, and various underground engineering applications. Fractures have a critical effect on the fluid flow through low-permeability rocks since they serve as the major flow channels in the rock formation. Consequently, the evaluation of fracture permeability is crucial to many engineering

Blasting operations create significant problems to residential and other structures located in the close proximity of the mines. Blast vibration is one of the most crucial nuisances of blasting, which should be accurately estimated to minimize its effect. In this paper, an attempt has been made to apply various models to predict ground vibrations due to mine blasting. To fulfill this aim, 112 blast

The rational choice of perforation arrangement and injection angle is of great significance to improve the efficiency of synchronous fracturing and to achieve the stimulation of the shale reservoir. In this paper, the influence of perforation angle and perforation arrangement on the crack propagation mechanism and rock failure mode of synchronous fracturing is studied based on the particle discrete

The characteristics of the particle size distribution (PSD) are an important reflection of energy consumption during rock drilling and drilling efficiency. A new approach incorporating both fine and coarse fractions of the PSD to supplement the typical approach of merely utilizing D50 (50% passing diameter) to index drilling resistance and efficiency is reported in this paper. A series of drilling

Main factors influencing the wide range of apertures (from 50 to 400 mm) of mining-induced horizontal fractures (Torezko-Snezhnyanskaya coal area, Ukraine) at traditional (without grout injection into bed separation) longwall coal mining were analysed. Apertures of these fractures were directly measured (using an original experimental device) in vertical boreholes drilled from ground surface to active

Safe mining depth constitutes the key to the open-pit mine development, it is significant to research the safe mining depth. First, According to the field geological investigation and geophysical exploration, the existing landslides were summarized and analyzed to obtain the potential destabilization and failure modes in mine, which laid the effective reference for the slope stability analysis in the

Acoustic transmission along the drill string for measurement while drilling (MWD) is an effective solution to the problem of the low transmission rate that results from mud pulse transmission. However, the actual downhole acoustic waves are affected by many factors, such as drilling fluid properties and, formation boundaries, and their effects on acoustic wave transmission in drill string are not thoroughly

Many large engineering projects, e.g., the Sichuan–Tibet Railway, inevitably cross the earthquake active areas and the geology complicated zones, facing the challenges of dynamic disturbances and disasters. In view of this, the conceptualization of engineering disturbed rock dynamics is proposed in this paper, aiming to systematically study the rock dynamic behavior and response subjected to engineering

The classification of rock slopes and the determination of rock extent are essential for slope stability analysis. At present, the efficiency of artificial methods is low and affected by subjective factors. A convolution neural network model for rock slope image analysis is established based on the Tensorflow. 80,000 rock slope images are extracted and compressed using convolution and pooling. Then

In an enhanced geothermal system (EGS), fractures and fracture networks are the predominant elements for fluid flow and heat transfer through the artificial reservoir. In this work, different conceptual discrete fracture networks were generated by characterizing the fracture number, fracture bifurcation and fracture connectivity of the fracturing area. A thermal–hydraulic (TH) coupled mathematical

Understanding the consequences of mining is most important in order to prevent negative outcomes for the environment as natural systems are used by humans for agriculture/silviculture. The present manuscript deals with the impact of subsidence due to underground coal mining on native soil. Depth-wise changes in soil texture and nutrient components in four layers; 0–15 cm, 16–30 cm, 31–45 cm and 46–60 cm

In recent studies, the links between hydrocarbon accumulations and gold mineralizations have been examined. According to the results obtained from these studies, it has been reported that gold and hydrocarbons are carried and deposited by the same hydrothermal fluids. In the Seferihisar Uplift, the Efemçukuru Gold Operation possesses the largest proven gold reserves of Turkey. For this reason, in this

The determination of deformation parameters of rock material is an essential part of any design in rock mechanics. The goal of this paper is to show, that there is a relationship between static and dynamic modulus of elasticity (E), modulus of rigidity (G) and bulk modulus (K). For this purpose, different data on igneous, sedimentary and metamorphic rocks, all of which are widely used as construction