Diamond Bit Flow Patterns
There are two main flow patterns in diamond bits:
1. Cross Pad Flow System (feeder/collector system)
a) the fluid travels along the high pressure “primary fluid courses” (those which connect to the crowfoot), to a point where “low pressure collectors” draw the fluid across the diamond pad
b) this ensures that the diamonds towards the outside diameter are cleaned and cooled
c) The HSI should be between 1.5 and 2.5.
2. Radial Flow System
a) provides a “high pressure primary fluid course” for each diamond row
b) permits fluid to travel in front of, and behind each diamond pad to facilitate cuttings removal and cooling
c) maintains uniform horizontal fluid velocity by tapering fluid course depth as they approach the outside diameter
d) The HSI should be between 2.0 to 3.0.
