Abstract: The authors have previously developed and proposed methods to estimate the in situ rock strength and tooth wear while drilling with roller-cone bits [Karasawa et al., 2002, ASME J. Energy ...

Abstract: New methods to estimate both the rock strength and tooth wear while drilling with roller-bits were developed and proposed in Part 1. These methods were derived from the results of drilling ...

Abstract: This paper proposes new methods to estimate both the rock strength and tooth wear while drilling with roller-bits. Laboratory drilling tests were conducted to obtain the penetration rate, bit ...