RT Journal Article
ID 6c9df51114d0fc96
A1 liao, hualin
A1 Li, Gensheng 
A1 Yi, Can 
A1 Niu, Jilei 
T1 EXPERIMENTAL STUDY ON THE EFFECTS OF HYDRAULIC CONFINING PRESSURE ON IMPACTING CHARACTERISTICS OF JETS
JF Atomization and Sprays
JO AAS
YR 2012
FD 2012-10-04
VO 22
IS 3
SP 227
OP 238
K1 jet
K1 confining pressure
K1 rock breaking
K1 cavitating jet
K1 abrasive jet
AB The high hydraulic confining pressure exhibited in oil-well downholes and deep water conditions affects jet dynamic characteristics remarkably. A set of devices and equipment were developed to study the influence of confining pressure on jet impact pressure and rock-breaking efficiency. The three most popular jet types−a conical water jet, a cavitating jet, and an abrasive jet−were studied with a maximum nozzle pressure drop of 25.0 MPa and maximum confining pressure of 20.0 MPa. Results clearly reveal the close relationship among confining pressure and jet impact pressure and rock-breaking efficiency. The axial jet impact pressure and rock removal volume decrease while as confining pressure increases, and the decreasing curve becomes flattened at a certain point. Under the same conditions, the rock-breaking efficiency of the cavitating nozzle jet is higher than the conical nozzle jet, and cavitating erosion and pressure fluctuation are the important factors affecting jet rock-breaking efficiency. Furthermore, under confining pressure conditions, pure water jets have an optimal standoff distance about 3 to 5 times that of the nozzle outlet diameter, at which the highest rock removal volume is achieved. According to the study, a drop of jet impact pressure with growth of confining pressure may be the main reason for the decreasing rock-breaking capability. The study could be used as a reference for setting and optimizing jet application conditions, and also could be adopted for developing working parameter selections as well as guiding the nozzle structure designs.
PB Begell House
LK https://www.dl.begellhouse.com/journals/6a7c7e10642258cc,61e24b9170ac454d,6c9df51114d0fc96.html