In order to investigate the fracturing of the bedrock and its possible heterogeneous distribution in situ, four boreholes equipped with double-U geothermal pipes of 100 m long were installed on the campus of the University of Liege (Liege, Belgium) over a surface area of 32 m2. The bedrock, which starts at a depth approximately of 8 m, is quite fractured and consists mainly of siltstone and sha...

BACKGROUND Microfracture and drilling are bone marrow-stimulation techniques that initiate cartilage repair by providing access to cell populations in subchondral bone marrow. This study examined the effect of hole depth and of microfracture versus drilling on subchondral bone repair and cartilage repair in full-thickness chondral defects. HYPOTHESES Repaired subchondral bone does not reconst...

Madan Bozorg is an active copper mine located in NE Iran, which is a part of the very wide copper mineralization zone named Miami-Sabzevar copper belt. The main goal of this research work is the 3D model construction of the induced polarization (IP) and resistivity (Rs) data with quantifying the uncertainties using geostatistical methods and drilling. Four profiles were designed and surveyed us...

Drilling is the most frequently employed operation of secondary machining for fiber-reinforced materials owing to the need for structure joining. Delamination is one of the serious concerns during drilling. Practical experience shows that an eccentric twist drill or an eccentric candle stick drill can degrade the quality of the fiber reinforced material. Comprehensive delamination models for th...

Abstract Wellbore instability severely constrains the exploration and development of shale gas. In order to evaluate impacts anisotropy water on wellbore instability, three different types criteria are fitted strength data LMX shales with moisture contents. A new model transversely isotropic borehole stability considering compliance incremental tensor induced by natural fractures is proposed, t...

This paper presents a prototype of a silent, remotely-operated microwave drill (MWD) for concrete. The MWD concept, based on the induced thermal-runaway instability and hotspot formation effects, is pushed here beyond the limit of quarter-wavelength drilling depth. This extension is achieved by a slow mechanical rotation (~20-rpm) of the entire coaxial structure penetrating as a hollow reamer i...

The process of borehole drilling is a nonlinear and many dimensional process. During drilling it is possible occurrence of some complications (for example transition of drilling tool in layer with anomalous pressure). New method of identification of rock layers with anomalous pressure was proposed and tested on real plant data.

Formation anisotropic constants play an important role in the determination of formation stresses, fractures, lithology, and mechanical properties. These characteristics provide critical inputs to wellbore stability during drilling optimal completion designs hydrocarbon bearing reservoirs. However, there are no available techniques for estimation a sub-set using Logging-While-Drilling (LWD) son...

Like natural seismicity, induced seismicity caused by injection also shows a power law size distribution, and its gradient b-value is used for seismic hazard analysis. Despite the well-known result that negatively correlated with differential stress earthquakes, there no similar correlation variations because nearly constant injection-induced we thus investigate dependence on relative shear act...