Posted on September 6, 2021
Port Fourchon is close to the offshore oil platforms in the US Gulf, but it is also at the southern edge of Louisiana where the land is fading away.
Port Fourchon became momentarily famous when it was reported that it was the landing spot for one of the most powerful hurricanes to ever hit Louisiana.
Two days later crews were clearing the debris from the only highway that serves the port to begin evaluating the damage caused by the hurricane, whose 150 mile per hour winds pushed a wall of water over the vital offshore oil supply base that is barely above sea level.
There is no quick fix for what has been broken there. “There is no electricity and there will be no electricity for a long time. In our community we have no running water,” said Chet Chiasson, the executive director of the port in an interview with National Public Radio. “We will come back as soon as possible, but the bottom line is there is a long road ahead.
“There are vessels in places where they are not supposed to be, to say the least,” he noted. The damage to the fleet of supply vessels serving offshore producers, particularly those in deep water, appears limited.
Only about 40 vessels rode out the storm in the port, according to a report from the newspaper, Houma Today, which said in normal times more than 200 vessels will be in port each day.
Repairs will take weeks of work—Chiasson was unable to say how many.
But the hurricane also represents a dramatic event in the sea’s relentless advance over what was once swampland and marshes.
The port’s tenuous position was described in a paper (OTC 30940) presented at the recent Offshore Technology Conference by two metocean engineers from Shell, Octavio E. Sequeiros and Sergio Jaramillo.
“Port Fourchon is at the edge of the Mississippi Delta facing the sea, one of the world’s most vulnerable low-elevation coastal zones. It is highly exposed to storm surge and wave-induced inundation under hurricanes which regularly visit the Gulf of Mexico. In addition, it experiences one of the largest rates of subsidence in the world, which combined with sea-level rise, will increase the site vulnerability in the coming decades.”
Based on aerial pictures of Port Fourchon on its website, it looks like a cluster of small islands, which is evidence of the land lost. Researchers at the US Geological Survey said losses since the 1930s have ranged from 32 to 11 square miles a year. The 2017 report said losses had slowed back then. A key reason: “The lack of major hurricane effects in coastal wetlands” in the previous 8 years.”
Reengineering the Port
The authors, who live in the Netherlands, described a future where the water will rise above the land.
The data in the paper was focused on a key Shell facility at the port, the Port Fourchon Junction. It is the facility at the landing point for the import pipeline serving the Mars platform and others coming on land. While it is closer to the open water of the Gulf than the port, it is behind a breakwater and beach, so the flooding risk is about the same.
Their modeling of long-term changes in water level, based on the multiple factors reshaping the coast, including hurricanes. Their conclusion: What sounds like a small change in the relative sea level presents significant challenges due to the land subsidence and rising water.
“At the present time Port Fourchon facilities are above water even under high tide.
“Accounting for the observed rates of subsidence and eustatic sea level (ocean level) rise, Port Fourchon relative sea level rise will be 0.59 meter in 50 years. Under such circumstances Port Fourchon facilities will be mostly under water.”
For Shell, this is a solvable long-term engineering problem using its platform design expertise.
“As most of the natural terrain where Port Fourchon facilities are located is expected to be permanently under water by the end of the lifespan, design guidelines may well be taken from fixed offshore structures.”
They suggested raising the pipeline facility to comply with API RP 2MET 2019, which is used by offshore platform designers to answer questions such as how high the decks of the vessel need to be based on ocean conditions.
Rebuilding the port similarly to a fixed platform would be a very costly option for the port, which is many times larger.
What they describe represents major investments. In the near term, the damage resulting from Hurricane Ida will require expensive repairs. Longer term, work is needed to keep the port and its highway access above water.
Given the critical role Port Fourchon plays in the offshore oil business—it services more than 90% of the Gulf of Mexico’s deepwater oil production, according to its website—its survival seems assured for now.
Long term, the land around it is fading.
The future of the land at the southern edge of Louisiana is in doubt for a variety of reasons.
At the top of the list is compaction of the soil, which lacks the silt provided by regular flooding by the Mississippi River. Flooding ended when the US Army Corps of engineers surrounded the Mississippi by unbroken levees that also ensure a strong current to keep the deep channel clear.
The organics-rich swampy soil becomes compacted over time and when saltwater invades—which is speeded by rising ocean levels and canals built by oil companies to reach producing wells. Those canals also create highways in the marshes which create an opening for saltwater incursion.
There are many variables to consider for prediction of the future.
The modeling completed went well past 2050 when the major oil companies that dominate deepwater development, such as Shell, and Chevron, which manages the port, will be responding to the intense pressure to transition away from fossil fuel.
By then the Gulf of Mexico oil and gas business will be more than 100 years old.
The pace of land loss might be slowed, or even reversed, if massive plans to create openings in the levees release enough water and slit to restore land around the river.
On the other hand, global warming, which is raising the level of the ocean, could alter the coast.
Two hurricanes, named Cristobal and Laura, hit the western part of Louisiana last year and resulted in minor flooding at Port Fourchon—about 0.3 m, according to the OTC paper.
Based on the surge—the weather bureau estimated 12–16 ft for Ida compared to 4–6 ft for Laura in that area—flooding was considerably deeper this time. Pictures shot on 30 August showed scattered equipment, standing water, and some roofs torn off.
Those distant events forced Port Fourchon to act quickly to maintain offshore access.
Last winter the port had to quickly convince the Corps of Engineers to do some “emergency dredging” because a key channel had been silted up due to last year’s run on hurricanes that hit Louisiana, according to the port’s newsletter.
As crews clear away power lines and debris on Louisiana Highway 1 (LA 1), Chiasson said the crews will also be making sure it is ready to handle the heavy equipment needed to get the port back up and running.
Maintaining that strip of land has required significant government support as well as tolls paid by traffic, including the 1,200 trucks a day serving the port when it is running normally.
In June 2020, the US Department of Transportation awarded a $135-million federal grant for elevation of about 8 miles of elevated roadway needed to complete a $350-million project funded in 2008.
At this point, there is no way of knowing the full cost of Hurricane Ida based on pictures of its chaotic aftermath.
“It is amazing what hurricane weather does,” Chiasson said, adding it leaves some facilities in pretty good shape with only cosmetic damage to fix while others are completely destroyed.
