Research on the modulation mechanism and rock breaking efficiency of a cuttings waterjet

• Published in: Energy science & engineering Vol. 7; no. 5; pp. 1687 - 1704
• Main Authors: Wang, Peng, Zhao, Bo, Ni, Hongjian, Li, Zhina, Liu, Yuandong, Chen, Xinyong
• Format: Journal Article
• Language: English
• Published: London John Wiley & Sons, Inc 01.10.2019; Wiley
• Subjects: Abrasives; Computer simulation; cutting waterjet; Drilling; Efficiency; hard rock breaking; Influence; Modulation; modulation mechanism; Parameters; Rocks; rock‐breaking experiment; Silicon carbide; Silicon steels; Steel; Suction; Velocity
• ISSN: 2050-0505; 2050-0505
• DOI: 10.1002/ese3.385

The feasibility of a cuttings waterjet directly modulated in the bottom hole is discussed from the aspects of cuttings suction and rock‐breaking efficiency. The particle waterjet modulation mechanism using a Helmholtz oscillating cavity is studied through numerical simulation and the rock‐breaking efficiency of five types of particles (including cuttings, steel balls, steel emery, garnet, and silicon carbide) is studied through experiment. The influences of particle parameters (such as diameter, density, and concentration) and operation parameters (such as standoff distance, pump pressure, and confining pressure) on the suction and rock‐breaking effect of different particles are analyzed. The results show that all particle types with different parameters could be indrawn into the Helmholtz oscillating cavity with two symmetrical suction ports and could be accelerated to considerable velocity amplitude to impact rock. The rock‐breaking efficiency of pure cuttings was lower than fractional cuttings (ie, 50% cuttings and 50% steel balls) and pure steel balls, but the pure cuttings can be used as an effective assisted rock‐breaking method. The research results lay a foundation for development of a cuttings waterjet directly modulated in the bottom hole for assisting rock‐breaking technology. The feasibilities of cuttings waterjet directly modulated in the bottom hole are discussed from the aspects of cuttings suction and rock‐breaking efficiency in this paper. The modulation mechanism of particle jet using Helmholtz oscillating cavity is studied through numerical simulation and the rock‐breaking efficiency of five type particles (including cuttings, steel ball, steel emery, garnet, and silicon carbide) is studied through experiment. The research results lay a foundation for the development of cuttings waterjet directly modulated in the bottom hole assisted rock‐breaking technology.