Waterjet-Assisted Drag Bit Cutting in Medium Strength Rock: A Fundamental Investigation.
Geier-JE; Hood-M; Thimons-ED
Proc 28th U S Rock Mechanics Symp Univ of Arizona 6/29-7/1/87 PP 953-961 :953-961
This paper presents hypotheses for the mechanism by which water jets reduce the specific energy of cutting for drag bits. Several of these are shown to be inconsistent with published evidence and new observations. The notion of a limiting cutting speed, above which water jets would be incapable of rendering assistance, was shown to be improbable. The hypothesis that seems most plausible is that specific energy reductions are mainly due to the erosion of crushed material from in front of the bit. This hypothesis leads to a prediction that, for a given rock type and jet-bit configuration at a constant depth of cut, the reduction in bit forces should be a function of dw/dx, the jet energy spent per unit length of cut. This dependence upon dw/dx is shown to be consistent with previously reported results.
Proc. 28th U.S. Rock Mechanics Symp., Univ. of Arizona, 6/29-7/1/87, PP. 953-961