The approach of Tropical Storm Nate forced the shut-in of more than 70% of the U.S. Gulf of Mexico’s (GoM) daily oil production and 53% of its daily gas production as operators gear up for another round of severe weather.

The National Hurricane Center (NHC) forecast the tropical storm to near hurricane status as it approached Mexico’s Yucatan Peninsula on Oct. 6 before moving into the U.S. Gulf Coast as a possible hurricane Oct. 7, bringing with it life-threating storm surge flooding along parts of the northern Gulf Coast.

“Reports from an Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds are near 50 mph (85 km/h) with higher gusts,” the NHC said in a recent bulletin. “Strengthening is forecast during the next couple of days, and Nate is expected to become a hurricane by the time it reaches the northern Gulf of Mexico.”

The projected path takes the storm through the most-active oil-producing region of the GoM. Nate has already stifled about three times as much GoM crude production as Hurricane Harvey did in August. At its height, Harvey shut-in about a quarter of the region’s oil production.

Operators began evacuating ahead of the storms arrival as early as Oct. 5 as they continued to monitor the storm.

Shell said Oct. 6 that it was securing its Mars, Ursa, Olympus and Ram Powell production hubs in the eastern GoM as well as shutting in production.

“Drilling operations have been suspended and all personnel are returning to shore,” Shell said, adding GoM employees will work from its Robert Training Center in Louisiana and other secure, remote locations.

“Our platforms are designed to withstand hurricane force conditions and our employees are trained to take immediate action when necessary to keep each other, the environment and our assets safe,” said Phil Smith, Shell’s Manager for Emergency Management in the Americas.

Other GoM operators also have taken precautions:

  • ExxonMobil Corp. said Oct. 6 it stopped oil production at its Julia and Hadrian South subsea production systems;
  • ConocoPhillips is evacuating nonessential personnel from its Magnolia oil platform in the central GoM;
  • Anadarko Petroleum Corp. said on Oct. 5 that it has removed all personnel from Horn Mountain, where it has shut in production, and planned to do the same Oct. 6 at its Marlin facility. The company also said it was removing all nonessential personnel from its Constitution, Holstein, Lucius and Marco Polo platforms Oct. 5;
  • Chevron said Oct. 5 that it was shutting production at its Blind Faith, Genesis, Jack/St.Malo, Petronius and Tahiti facilities and evacuating personnel. The company went a step further and shut down its 6,598-km (4,100-mile) pipeline subsidiary, saying it would not accept or deliver crude until after Nate subsided;
  • Statoil also said Oct. 5 that it was evacuating its Titan platform; and
  • BP said on Oct. 5 that it began removing all remaining offshore personnel and shutting-in production at its four operated platforms: Thunder Horse, Atlantis, Mad Dog and Na Kika.

Based on operator reports, the U.S. Bureau of Safety and Environmental Enforcement (BSEE) said more than 71% of the GoM’s oil production and more than 53% of the natural gas production has been shut-in. An estimated 1.2 MMbbl/d of oil and 1,713.31 MMcf/d of production will be disrupted, the agency said.

Offshore workers were evacuated from 66 production platforms and five rigs in the GoM as of 11:30 a.m. CDT Oct. 6, according to BSEE. That left about 8.96% of the 737 manned platforms without personnel along with 20% of the non-dynamically positioned (DP) rigs in the GoM.

In addition, BSEE said 11 DP rigs—61% of the DP rigs operating in the GoM—have been moved out of the storm’s path.

“DP rigs maintain their location while conducting well operations by using thrusters and propellers, the rigs are not moored to the seafloor; therefore, they can move off location in a relatively short time-frame,” BSEE said in its storm update. “Personnel remain on-board and return to the location once the storm has passed.”

Matt Rogers, meteorologist at Commodity Weather Group, said the speed of the storm could leave it as a Category 1 hurricane with up to 80 mile per hour (129 kph) winds.

“In our view it is not going to be strong enough to do damage” to offshore production facilities, he told Reuters. “Usually when storms move this quickly they have troubles developing.”

Nate is forecast to make landfall somewhere west of Mobile Bay, Alabama, and east of New Orleans, Louisiana. It expects between 4 inches and 6 inches of rain to fall in the path of the storm.

The state of Louisiana and several parishes have already declared states of emergency. Officials in New Orleans, which was battered by Hurricane Katrina in 2005, have done the same and ordered a mandatory evacuation for residents outside the city levee system.

In New Orleans the U.S. Coast Guard declared condition “X-Ray” at the port ahead of Nate, which means force winds are possible within 48 hours. Commercial vessels and large barges must report to the Coast Guard to decide whether to depart or remain.

Parts of the Mississippi River, which flows past New Orleans and is a major transit hub for oil and other commodities, have been closed to inbound deep draft vessels.

The region's oil refineries are still recovering from Harvey, which shut production at some plants for weeks. Producers also curtailed some production but quickly resumed output.

Royal Dutch Shell Plc decided against cutting operations at its 225,800-bbl/d Norco, Louisiana, refinery, reversing an earlier decision to cut rates.

Reuters contributed to this article.

Offshore