Can Nozzle Design Be Effectively Improved for Drilling Purposes


This paper describes continued research on the use of high pressure water jets as a means of improving drilling rate. In order to more effectively test the effect of stress on jet drilling rate, tests have been carried out in an underground mine. These tests have shown that stress markedly reduces jet cutting ability in rock in situ contrast with laboratory test conditions. In order to achieve improvement in performance, new nozzle designs have been developed which markedly increase jet performance in cutting rock in air. The potential of this development on conventional bit performance in downhole conditions is discussed together with an initial analysis of the problems which can be solved in fluid flow through a bit. A discussion on the relative merits of optimizing fluid impact force as opposed to optimizing fluid velocity or bit hydraulic horsepower concludes the paper.


Mining and Nuclear Engineering

Second Department

Mechanical and Aerospace Engineering

Document Type

Article - Journal

Document Version


File Type





© 1978 American Society of Mechanical Engineers (ASME), All rights reserved.

Publication Date

01 Jan 1978

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