Authors: R Ghosh Z X Zhang U Nyberg
Publish Date: 2014/08/12
Volume: 48, Issue: 4, Pages: 1731-1736
Abstract
Borehole instability causes borehole failure presenting a challenge to the drilling industry Muller et al 2009 Zhang 2013 The borehole stability of Marcellus shale wells in long wall mining areas in southeast Pennsylvania West Virginia and eastern Ohio has been evaluated by Wang et al 2014 Here the ground deformation caused by coal mining generates large ground movement and creates complex stress changes in subsurface rock This in turn triggers interruptions in the operation of the borehole well causing safety and environmental concerns Borehole walls may fail when the surrounding stress exceeds the tensile the compressive or the shear strengths of the rock formation whichever is reached first Zhang et al 2003 Horizontal well borehole stability is analyzed by the new in situ stress prediction model in shale gas reservoirs Yuan et al 2013 Besides this in hard rock underground mining such as sublevel caving SLC uncharged and undetonatedThe authors are grateful to the chargers especially Töre Nilsson at Malmberget LKAB for their cooperation during filming Special thanks to Anders Nordqvist at LKAB Kiruna and to Tomas Savilahti at LKAB Malmberget for providing data and valuable comments Thanks are also extended to the mine personnel working at Malmberget for their worthwhile support
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