%0 Journal Article
%T Contribution ¨¤ l'¨¦tude de la "taille" des roches Contribution to the Study of Rock Cutting
%A Nguyenminh D.
%J Oil & Gas Science and Technology
%D 2006
%I Institut Fran?ais du P¨¦trole
%R 10.2516/ogst:1975018
%X Une ¨¦tude exp¨¦rimentale d¨¦taill¨¦e du processus local de destruction des roches par un outil de forage p¨¦trolier a ¨¦t¨¦ faite par une m¨¦thode de similitude utilisant des mat¨¦riaux ¨¦quivalents tendres. On examine l'influence de la forme de l'outil, de la rugosit¨¦ du contact et de la ductilit¨¦ e globale   du mat¨¦riau. Les r¨¦sultats obtenus sont ensuite compar¨¦s ¨¤ ceux de l'analyse plastique par la th¨¦orie des charges limites. Cette ¨¦tude met en ¨¦vidence l'existence de deux modes de rupture, l'action diff¨¦rente du frottement superficiel selon le sens de l'¨¦coulement relatif du mat¨¦riau en contact, le ph¨¦nom¨¨ne de la ductilit¨¦ apparente qui d¨¦pend de la forme de l'outil ; elle pr¨¦cise les param¨¨tres m¨¦caniques importants du forage. A detailed experimental investigation of the local process of rock cutting by a drill bit was carried out on soft equivalent materials simulating rock under borehole conditions. Different factors were analyzed : the shape of the bit tooth, the roughness of ifs contact area, the average ductility of the materiat. The results obtained are then compared with those from a plastic analysis based on the peak lood theory. This investigation shows that there are two different modes of rock destruction, that the Coulomb friction has a different effect depending on the relative direction of flow of the materiat in contact with the bit, and that an apparent ductility of the materiat is linked to the shape of the bit teeth. Finally, the basic mechanical variables for drilling are described
%U http://dx.doi.org/10.2516/ogst:1975018