CASE STUDIES
MURRAY RIVER
Large Diameter Casing Installation
PROJECT SUMMARY
This pipeline crossing project at the Murray River required the installation of large diameter casing and pushed our technical limits.
The Crossing Company used horizontal directional drilling (HDD) to complete this project with a 60” ream pass and a total length of 1349m. The Tunneling Company installed large diameter telescoped casing with a hydro hammer.
KEY CHALLENGES
The project included a challenging design with a steep entry angle of 21 degrees and a final 60” ream pass. To ensure the crossing would be successful, a pneumatic hammer and buoyancy control were used during pullback.
The entry side started with 34m of 96” casing, followed by 70m of 84” casing and 107m of 72” casing. The earth was pulled out between each round of casing, leaving an opening for the pilot tube. After the pilot tube was installed The HDD Company reamed back and forth, eventually creating a 60” hole that could hold the 48” gas line.
Casing on the exit side of the project included 40m of 84” and 60m of 72” pipe.
Buoyancy control was utilized by The Crossing Company to help reduce expected theoretical pull forces. The product pipe was filled with water to help mitigate the high pull forces that we typically expect on long crossings with large diameter product pipe.
While using a pneumatic hammer during pullback is rare, it was also utilized to help overcome the higher than anticipated pull forces and made this project an overall success!
SERVICES PROVIDED
HORIZONTAL DIRECTIONAL DRILLING, PIPE RAMMING