Key problems in hydraulic rock drill design

Keyword(s):  
1987 ◽  
Vol 4 (2) ◽  
pp. 89-96
Author(s):  
Lee Da-Yi ◽  
Gao Lan-Qing ◽  
Fang Mei
Keyword(s):  

2013 ◽  
Vol 845 ◽  
pp. 934-938 ◽  
Author(s):  
Turnad Lenggo Ginta ◽  
Bambang Ari-Wahjoedi

Orthopaedic surgery procedure widely utilizes bone drilling in the work for correcting bone fracture and attaching prosthetics. Clean and accurately positioned holes are desired during bone drilling without damaging the surrounding tissues. However, bone temperature rises during drilling. It is always required to keep the temperature during drilling below 47 °C to avoid thermal osteonecrosis (bone cell death), which might lead to a loose of bone-implant interface. Drill design, drill parameters, and coolant delivery were believed to contribute to heat generation. As complex anisotropic biological tissues, determining the bone temperature during drilling is another issue. Complex mechanical and thermological properties are also other problems to be investigated due to the sensitivity to testing and specimen preparation.


2007 ◽  
Vol 47 ◽  
pp. 89-98 ◽  
Author(s):  
Sigfús J. Johnsen ◽  
Steffen Bo Hansen ◽  
Simon G. Sheldon ◽  
Dorthe Dahl-Jensen ◽  
Jørgen P. Steffensen ◽  
...  

AbstractIn the mid-1990s, excellent results from the GRIP and GISP2 deep drilling projects in Greenland opened up funding for continued ice-coring efforts in Antarctica (EPICA) and Greenland (NorthGRIP). The Glaciology Group of the Niels Bohr Institute, University of Copenhagen, was assigned the task of providing drilling capability for these projects, as it had done for the GRIP project. The group decided to further simplify existing deep drill designs for better reliability and ease of handling. The drill design decided upon was successfully tested on Hans Tausen Ice Cap, Peary Land, Greenland, in 1995. The 5.0m long Hans Tausen (HT) drill was a prototype for the ~11m long EPICA and NorthGRIP versions of the drill which were mechanically identical to the HT drill except for a much longer core barrel and chips chamber. These drills could deliver up to 4m long ice cores after some design improvements had been introduced. The Berkner Island (Antarctica) drill is also an extended HT drill capable of drilling 2 m long cores. The success of the mechanical design of the HT drill is manifested by over 12 km of good-quality ice cores drilled by the HT drill and its derivatives since 1995.


Author(s):  
Xiaoguang Geng ◽  
Wei Ma ◽  
Fei Ma ◽  
Zhihong Zhou ◽  
Yuchao Liu ◽  
...  
Keyword(s):  

Author(s):  
Genady P. Cherepanov

By way of introduction, the general invariant integral (GI) based on the energy conservation law is presented, with mention of cosmic, gravitational, mass, elastic, thermal and electromagnetic energy of matter application to demonstrate the approach, including Coulomb's Law generalized for moving electric charges, Newton's Law generalized for coupled gravitational/cosmic field, the new Archimedes’ Law accounting for gravitational and surface energy, and others. Then using this approach the temperature track behind a moving crack is found, and the coupling of elastic and thermal energies is set up in fracturing. For porous materials saturated with a fluid or gas, the notion of binary continuum is used to introduce the corresponding GIs. As applied to the horizontal drilling and fracturing of boreholes, the field of pressure and flow rate as well as the fluid output from both a horizontal borehole and a fracture are derived in the fluid extraction regime. The theory of fracking in shale gas reservoirs is suggested for three basic regimes of the drill mud permeation, with calculating the shape and volume of the local region of the multiply fractured rock in terms of the pressures of rock, drill mud and shale gas.


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