A Laboratory Study of High Pressure Fluid Jet Drilling
Authors: Sheshtawy Adel A. , Kennedy William A. 
Published: December 2007

This paper was prepared for the 48th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Las Vegas, Nev., Sept. 30-Oct. 3, 1973. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgement of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
This study deals with rotary high pressure jet parameters and the effect of nozzle geometry on the shape and performance of the jet. Pressures up to 15000 psi (1.55 kg/cm2) have been Pressures up to 15000 psi (1.55 kg/cm2) have been used with rock samples rotating from 150 to 300 r.p.m. and with the bottom-hole depth simulated up to 5000 ft. The effect of multi-jet reaction on rock surfaces is presented together with a general relationship for the depth of cut produced by a high pressure jet on the rock surface.

Introduction
High pressure jet drilling recently received considerable attention, as an effective method for oil well drilling, and the field tests of high pressure drilling gave successful results. High pressure drilling gave successful results. High pressure jet drilling outperforms rotary drilling pressure jet drilling outperforms rotary drilling because it transfers 80 to 90% of the available surface horsepower to the bottom of the hole for rock penetration, while rotary drilling transfers a maximum of 5 percent of the rig power to the drill bit. In rotary drilling the rest of the rig power either lays idle for tripping the drilling string or is consumed in friction and in circulating the drill cuttings from the bottom of the hole to the shaleshaker. Summers, Maurer, and others have investigated the relation between the crater formed by a high pressure water jet and the nozzle parameters, but most of the previous work has been done with a static nozzle for a prolonged time (0.5 - 30 seconds) under atmospheric prolonged time (0.5 - 30 seconds) under atmospheric conditions. In oil well drilling the jet action on the rock is in the order of milliseconds. The operation parameters of the static jet are completely different from the rotating jet due to the type of reflection surface and the amount of jet interference. The works of Cunningham and Eenin, Maurer and Eckel indicate the effect of down hole pressures on rock drillibility with conventional cutting edges. The failure of rock at depth under a rotary high pressure jet has not been investigated before. pressure jet has not been investigated before. Albertson, Eckel, and Farmer investigated fluid flow through different nozzle geometries.
The investigations were mainly theoretical and the experimental part of their work was not within the operating pressures of high pressure jet drilling.