2-kilometer HDD outfall on Trinidad

In the fall of 2022, Brownline USA helped complete a very long HDD outfall on the island of Trinidad. For the replacement of a multiphase pipeline, a 12” pipeline was brought to shore at the tip of the island.

This HDD was part of a large project to install a replacement pipeline for multiphase natural gas products. The total length of this pipeline will be 96 kilometers / 60 miles. To bring the pipeline to shore, a very long HDD outfall was launched from Galeota Point, the southeastern tip of Trinidad.

Under a mountain

The drill was set to cross under a small mountain on the tip of the island. At 40 m / 131 ft below sea level, the drill passed under the seaside cliffs. This trajectory means using a standard magnetic tool and surface coil installation for guidance was impossible. Brownline USA brought in the Drillguide Gyro Steering Tool, the most reliable tool to take accurate positional measurements for such a project. Without needing surface access, the GST accurately relayed the position of the drill head to the driller.

The rock formation near the entry point showed fracturing, which posed a serious challenge. To avoid inadvertent returns, casing was installed at entry. The annular pressure was constantly monitored using the Pressure-While-Drilling module inside the Gyro Steering Tool. Close monitoring of these pressure measurements reduced the risk of frac-outs and increased the safety of the installation.

Seabed punch-out

The drill exited 26 m / 85 ft below sea, where a dive team was deployed to assist. Because of the ongoing rainy season, the conditions for the crew working offshore were very challenging. Because of the accuracy of the Gyro Steering Tool, the drill punched out within tolerances even after travelling over 2 km / 6700 ft.

Brownline is proud to have made a contribution to this difficult project.

Back to overview