Drilling across a marshy area for Shell’s Zydeco pipeline

In the summer of 2020, Brownline USA’s Drillguide Gyro Steering Tool was instrumental in constructing a pipeline in Port Neches, TX. This was a project with many underground obstacles, a difficult location, and a pressing time limit.

The Zydeco Oil Pipeline, owned by Shell plc, transports crude oil along the Gulf of Mexico between Houma, LA and Houston, TX. To complete a connection to oil terminals in Port Neches and Nederland, TX, a 22” pipeline had to cross the Neches River. This crossing demanded the highest accuracy, as the exit point was located in a marshy area and needed to align perfectly with a pre-excavated underwater trench. In addition, there were many steel pipelines present in this area and this bore crossed under six of these. A guidance tool not affected by magnetic interference was needed to successfully steer this crossing. This is why contractor HardRock Directional Drilling brought in Brownline USA and their Drillguide Gyro Steering Tool.

For this crossing, a Brownline jetting assembly was used as well, as the soil consisted of clays and sands. The 4310 ft / 1314 m bore reached a depth of 155 ft / 47 m and followed a horizontal curve of 15°. Annular pressures had to be monitored closely using the GST’s Pressure-While-Drilling (PWD) module to minimize the risk of drilling fluids leaking into the Neches River. At the exit point, a spud barge and a diving support team were utilized.

In addition to the difficulties presented by the location of this project, there was also a time limit to its completion. This time of year is hurricane season in the Gulf Coast, which meant the drill needed to be completed as fast as possible. The efficiency and accuracy of the Drillguide Gyro Steering Tool made it possible to complete the pilot hole ahead of schedule.

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