The experimental study on the coal rock breaking efficiency of the self-rotating multi-orifice nozzle applied in URRS technique. Issue 6 (October 2021)

• Record Type: Journal Article
• Authors: Jin, Xin; Yang, Shunhui; Hu, Zhiqiang; Song, Xianzhi; Zhang, Hongbao; Cui, Yang
• Is Part Of: IOP conference series. Volume 861:Issue 6(2021)
• Publication Date: 2021-10
• Subjects: Earth sciences -- Periodicals; Environmental sciences -- Congresses; Environmental sciences -- Periodicals; 550.5
• DOI: 10.1088/1755-1315/861/6/062085
• Languages: English
• ISSNs: 1755-1307

Abstract

Abstract: China has abundant coalbed methane (CBM) reserves, but the production of single well is rather low. The Ultra-short Radius Radial System (URRS) technique can drill multiple radial branch holes with hydraulic jetting to effectively improve the production of single well. The high-pressure jet nozzle plays an important role in URRS technique and the structure of nozzle directly affects the efficiency of radial drilling. This paper adopts the experimental study on breaking coal rock efficiency of the self-rotating multi-orifice nozzle with different structures. The uniaxial compressive strength, tensile strength and shear strength of experimental rock samples were tested and calculated. Using natural coal and briquette rock, number of experiments under submerged conditions were carried out. The effects of nozzle pressure, jetting distance, jetting time and jetting direction on rock breaking effect were studied. The experimental results show that natural coal rock has strong anisotropy and demonstrate the coal rock breaking efficiency of the self-rotating multi-orifice nozzle. The key findings are expected to provide theoretical and technical support for development of CBM reserves by using the URRS technique.