000013426 001__ 13426
000013426 005__ 20161114164234.0
000013426 04107 $$aeng
000013426 046__ $$k2011-05-25
000013426 100__ $$aKiselev, A.
000013426 24500 $$aMathematical Modelling of Irreversible Deforming, Micro- and Macrofracture of Rock in the Vicinity of a Borehole in Its Dynamical Unloading

000013426 24630 $$n3.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000013426 260__ $$bNational Technical University of Athens, 2011
000013426 506__ $$arestricted
000013426 520__ $$2eng$$aThe rock formation at a depth of several thousand meters is exposed to a hydrostatic pressure. Drilling a borehole makes the drill experience same pressure from the walls of the borehole. On fast removing of the drill from the borehole the dynamical process of unloading borehole walls begins. The sharp decrease of normal pressure on the walls of the borehole brings to the increase of ring stresses. The waves of unloading propagate from the borehole, which could cause fragmentation of rock and blocking the borehole with fractured material. The goal of the present paper is to give the problem statement foe the dynamical process of unloading the internal walls of the borehole after removing the drill, and successive oil-bearing layer’s fracturing. The layer is represented by the model of damageable thermoelastoplastic material with two parameters of damaging (by evolution of micropores and by shear microfracturing). The criterion of the beginning of new free surfaces within the material) uses the principle of the critical value of specific dissipated energy.The problem is treated as two-dimensional (plane deformed state). This task is solved numerical modeling on Lagrancian mesh by method similar to M.L. Wilkins one and on local reconstruction of the Lanrangian grid in the vicinity of the fracture origination.

000013426 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000013426 653__ $$aComputational Simulation, Damageable Thermoelastoviscoplastic Solids, Fracture

000013426 7112_ $$aCOMPDYN 2011 - 3rd International Thematic Conference$$cIsland of Corfu (GR)$$d2011-05-25 / 2011-05-28$$gCOMPDYN2011
000013426 720__ $$aKiselev, A.$$iZacharov, P.
000013426 8560_ $$ffischerc@itam.cas.cz
000013426 8564_ $$s1016519$$uhttps://invenio.itam.cas.cz/record/13426/files/091.pdf$$yOriginal version of the author's contribution as presented on CD, section: RS 12 Computational Methods in Geotechnical Earthquake Engineering.
000013426 962__ $$r13401
000013426 980__ $$aPAPER