In spring 2007, the Guam Waterworks Authority awarded Michels Directional Crossings with a contract to construct two separate shore approaches in order to complete an ocean outfall project for sewage lines. Drilling out into open water at depths well over 100 ft was a new challenge for Michels — a challenge crews were well prepared for and not about to take lightly.
Guam is an island located in the western Pacific Ocean and is an organized unincorporated insular area of the United States. It’s also one of five U.S. Territories with an established civilian government. The trip to Guam was the second for Michels. The first time was back in 1996 when Michels was hired by the Public Utility Agency of Guam (P.U.A.G.) to install 1,760 ft of 28-in. HDPE pipe as an ocean outfall diffuser for discharge of treated sewage into Tipalo Bay – part of the Philippine Sea.
It may have taken crews 21 hours to arrive by flight, but it was a different story for all of the heavy equipment needed to complete the project. Tons and tons of the much-needed equipment was making its way to the island at a sea turtle’s pace and wasn’t scheduled to arrive until later in the month, giving the crew adequate time to acclimate themselves with the island surroundings.
Drill rigs and ancillary equipment, which included containers of specially made tooling reamers and pipe rollers crucial to the success of the project, had to be shipped from the United States over to Guam by way of Hawaii on a cargo ship. The process took 30 days from port to port to transfer all the heavy equipment from the mainland to Guam’s main harbor. Once the ship arrived in Guam, a recently commissioned land terminal crane purchased by the Guam government was used for the first time to remove the 35-ton drill rig and containers full of equipment from the ship’s hull.
Both HDDs were designed to exit out into deep water marks never before fathomed by Michels Directional Crossing. In order to accomplish the task ahead, special equipment had to be employed both on land and in the ocean.
On land it was a montage of centralizers that were manufactured specifically for this project. In the water, an ROV (Remotely Operated Vehicle) was planned for deployment down to the ocean floor. This would provide a safe means of reconnaissance for monitoring the exit location eliminating the need for treacherous deep sea diving support during non-crucial phases of the drilling operation.
As crews were getting ready to embark on yet another milestone HDD, they were making preparations for offshore support in order to successfully perform the directional drills with exits in over 100 to 280 ft of ocean water — some of the deepest waters Michels have ever worked in.
Michels was hired to conduct two separate deep exit shore approaches. The first one in the island’s capital of Hagatna, located in the most southern part of the island, consisted of drilling and installing 2,177-ft of 42-in. HDPE pipe in well over 250-feet of water. The second drill was located in the Northern District and consisted of drilling and installing 1,958 ft of 34-in. HDPE pipe and was in just over 100 ft of water.
“We kept a crew of Navy-trained divers with us at all times,” says Michels marine operations manager Ray Viator. “They needed to use a special mixture of gases when diving and could only stay on the bottom for 20-minute intervals because of how deep the water actually was.”
For both outfall installations, an approximate 13-in. diameter pilot hole was drilled through limestone formation and exited out onto the ocean floor. The ROV was then launched from a work platform stationed out in the Pacific Ocean sending back real-time physical verification underwater of the accuracy at exit point. Once the location was verified and approved, deep sea divers were deployed from their work boat to attach the first reamer to a drill stem to begin reaming operations.
For the 34-in. line, two ream passes were conducted with the final ream pass at 42-in. in diameter. For the 42-in. line, three ream passes were conducted with the final ream pass at 54-in. in diameter. The various reamers provided were custom manufactured to handle the diverse coral/limestone formation and were attached to the drill stem utilizing offshore diver support, then the reamer was pulled back inland by the drill rig to enlarge the hole to accommodate installation of the separate HDPE outfall lines.
Record water depths exceeded 200 ft while divers worked at attaching specialized tools from the barge to the rear end of the reamer in order to maintain continuity between the entry hole and the exit hole. Underwater cutting gear was also used during reamer hook-ups.
Besides the deep water, crews were shaken by at least a dozen earthquakes during the year they spent working on the jobsite. Quakes ranged from 5.0 to 5.6 on the Richter scale. For some of the crewmembers, it was the first time ever experiencing an earthquake. “I was sound asleep when the first one hit soon after we arrived,” says Viator. “Next thing I knew I was thrown onto the floor.”
Another obstacle that occurred after one of the many earthquake aftershocks was having a recently drilled HDD pilot-hole collapse. When that happens – crews have to start the drilling process all over again.
Despite the record-breaking deep water depths and a significant number of earthquakes, the HDD job Michels Directional Crossing did for the Guam Waterworks Authority was another project completed, on time and within budget. The final pullback was done in November 2008 and the final tie-ins were completed in January 2009.
“This is why we do what we do,” says Craig Larson, Michels project manager for the Guam Project. “At Michels, we love a challenge and the opportunity to break new ground in the world of Directional Crossings.”
This article was submitted by Michels Directional Crossings.