For the third year in a row, GeoEngineers took home a Grand Award at the American Council of Engineering Companies of Missouri (ACEC) Engineering Excellence Awards. The Pipeline Crossing of Mississippi River Levee project was the top in the energy category. This annual program recognizes the state’s best engineering achievements, and the awards are among the most prestigious in the industry.
The winning project featured the installation of three Chevron pipelines using horizontal directional drilling (HDD) beneath the Mississippi River and its levee near Empire, Louisiana. The US Army Corps of Engineers (USACE) has become more restrictive in its regulation of construction around Louisiana’s levee system in recent years, especially with images of Hurricanes Katrina and Rita fresh in the nation’s memory.
GeoEngineers worked with Chevron to create HDD engineering designs and specifically evaluated hydraulic fracture and inadvertent returns and their effects on the levee. Hydraulic fracture occurs when the pressure required to keep drilling fluid flowing through the hole underground causes the surrounding soil to expand and eventually fracture, allowing drilling fluid to escape the HDD hole. When these drilling fluid leaks reach the ground surface, they are known as inadvertent returns. This subject is particularly important to the USACE because of the need to protect the levee system integrity and safety for the general public. GeoEngineers also provided HDD construction consulting services for the project.
Factors contributing to project success included:
- Constant communication with the project team and collaborative interaction with USACE
- Adjustments to standard HDD design and construction procedures
- Careful monitoring of drilling fluids and down hole annular pressures
By implementing GeoEngineers’ engineering recommendations and construction mitigation techniques, this approach demonstrated that even the most difficult HDD installations beneath levees are possible—without reducing the levees’ ability to protect coastal environments, economies and the general public.