Importance

Loading Importance Indicators...

Abstract

A drill string with a bit at one end is used to dig an underground borehole. When the drill string exits the borehole at a surface exit point, a pullback adapter is used to interconnect the bit with an above-ground utility line. A drilling rig retracts the drill string from the borehole. As the drill string is pulled back through the borehole, the trailing utility line follows along its underground path. As the utility line is pulled through the borehole, the connector biases the utility line to the center of the borehole. Such biasing reduces the risk of ensnaring of the connector and utility line by the borehole walls during the pulling process.

Loading the Abstract Image...

First Claim