Investigations over two major tectonic zones in the Hallandsås Horst, Southern Sweden were carried out in connection with a railway tunnelling project. A combination of resistivity imaging, core drilling and geophysical logging was found to provide a good overview of the variation in rock quality and detailed information on the engineering geological characteristics and genesis of the strata. R...

Drilling-induced delamination is among the major concerns of applying the fiber-reinforced composite materials in various industries. Core drill ossesses the advantage for reducing the delamination by distributing the drilling thrust force toward the drill periphery. The thrust force of core rill varying with the conditions in drilling carbon fiber reinforced plastic (CFRP) is experimentally in...

During the Integrated Ocean Drilling Program (IODP) Expedition 331 at the Iheya North hydrothermal system in the Mid-Okinawa Trough by the D/V Chikyu, we conducted microbiological contamination tests of the drilling and coring operations. The contamination from the drilling mud fluids was assessed using both perfluorocarbon tracers (PFT) and fluorescent microsphere beads. PFT infiltration was d...

The first stage to have access to a reservoir is the drilling operation. The proper development of this operation plays a major role in increasing productivity. It must be pointed out that the drilling fluid (mud) is pivotal in achieving this objective. Among these fluids, water-based fluids are the most common ones, which have been utilized to drill approximately 80% of all wells and are m...

Core drilling has been widely used in mineral exploration with diamond-impregnated technology. Automation is a critical technology improving core efficiency and reducing costs, but there no complete automation that can control the entire process. In this paper, an electric drive laboratory system was established using programmable logic controller (PLC) A proportional integration differentiatio...

Multiplicity of the effective factors in drilling reflects the complexity of the interaction between rock mass and drilling bit, which is followed by the dependence of parameters and non-linear relationships between them. Rock mass or, in other words, the formation intended for drilling, as the drilling environment, plays a very essential role in the drilling speed, depreciation of drilling bit...

It is now commonplace for non-destructive X-ray computed tomography (CT) scans to be taken of core recovered during a drilling project. However, other forms of tomographic scanning are available, and these may be particularly useful for core that does not possess significant contrasts in density and/or atomic number to which X-rays are sensitive. Here, we compare CT and neutron tomography (NT) ...

The onset of the Paleocene–Eocene thermal maximum (PETM) and associated carbon isotope excursion (CIE; approx. 56 Mya) was geologically abrupt, but it is debated whether it took thousands of years or was effectively instantaneous. Wright and Schaller (2013) published a significant new record of the onset of the CIE, and claimed that it could be resolved across 13 annual layers in a drill core t...

a r t i c l e i n f o In many mining, civil, and petroleum engineering applications diamond bit drilling is widely used due to high penetration rate, core recovery and its ability to drill with less deviation. Recently, many research have been conducted to estimate the penetration rate of diamond drilling which can be considered as one of the most important parameters in project planning and co...

Drilling induced core fractures, usually ignored in standard core logging, contain substantial information on the directions of horizontal stresses and the relative magnitudes of the three principal stresses. These fractures have a variety of shapes, variously referred to as petal, petal-centreline, saddle, cup, and scallop. Surprisingly, the morphology of the fractures suggests they are produc...