Tropical Storms Marco and Laura tore through the Caribbean and Gulf of Mexico on Sunday, forcing oil and gas producers in the region to shut in some production facilities.
Marco, which weakened from a hurricane to a tropical storm on Sunday, is forecast to make landfall along the Louisiana coast on Monday.
Laura, which hit the Dominican Republic and Haiti earlier on Sunday, killing at least 10 people before striking Cuba on Sunday evening, is forecast to strengthen into a hurricane before making landfall in Texas or Louisiana on Thursday.
Norwegian player Equinor has finished evacuating its Titan oil-production platform in the US Gulf of Mexico and has shut in oil production at the facility, a spokesman told Reuters on Sunday.
Anglo-Australian player BHP also shut-in and evacuated its Shenzi and Neptune oil platforms, a spokeswoman said.
Other players, including BP, Chevron and Shell, had shut-in 58% of the US Gulf's offshore oil production and 45% of natural gas production on Sunday.
The region accounts for 17% of total US oil production and 5% of US natural gas output.
The Louisiana Offshore Oil Port (LOOP), the largest privately owned crude terminal in the US, shut its Marine Terminal operations on Sunday due to the threat from the storms.
Clovelly Hub deliveries remain normal, LOOP said on its website, adding that it is executing an inclement weather plan.
Back-to-back hurricanes hitting the US coast within days could result in a prolonged period of hazardous weather, the US National Hurricane Center said on Sunday.
The US Federal Emergency Management Agency has sent teams to operations centers in Louisiana and Texas, a spokesman said.
The agency is prepared to handle back-to-back storms, he said, pointing to 2004 when four hurricanes took aim at Florida in a six-week period.
In Grand Isle, at Louisiana's southern tip, authorities were placing sandbags to bolster its protective levy while energy companies pulled workers from offshore platforms and shut down oil production.
Officials in Louisiana's coastal Lafourche Parish ordered residents of low-lying areas to evacuate by noon on Sunday.
The US Coast Guard also raised its warning for the Port of New Orleans, calling for ships to make plans to evacuate some areas.
The storms added to worries about the spread of Covid-19. Tulane University, the largest private employer in New Orleans, said it will close its testing center on Monday.
US President Donald Trump issued a disaster declaration on Sunday for Louisiana. He had previously issued a similar declaration for Puerto Rico.
Louisiana Governor John Bel Edwards warned that tropical storm-force winds would arrive by Monday and told residents that if they did not leave by Sunday night they should be prepared to ride out both Marco and Laura.
Laura could strengthen into a Category 2 or 3 hurricane on the five-step Saffir-Simpson scale for measuring hurricane intensity and move west, closer to Houston, said Chris Kerr, a meteorologist at DTN, an energy, agriculture and weather data provider.
Category 2 storms have sustained winds of at least 96 miles per hour. The threshold for Category 3 storms is 111 mph.
Dominican Republic deaths
In the Dominican Republic, at least three people died, including a mother and her seven-year-old son, due to collapsing walls.
Laura knocked out power to more than 1 million people in that country, forced more than a thousand others to evacuate and collapsed several homes along the Isabela River, authorities said.
In Port-au-Prince people wading waist-deep in muddy water in some of the worst flooding the Haitian capital has seen in years.
Haitian authorities reported seven deaths, including at least two people swept away in flooding and a 10-year old girl crushed when a tree fell on her home. Coastal neighborhoods of the capital were strewn with debris.
Laura hit eastern Cuba on Sunday evening with sustained winds of 60 mph downing trees and ripping flimsy roofing from buildings as it began a forecast 24-hour-treck from east to west along the southern coast of the largest island of the Caribbean.
The Cuban government said power was cut in the easternmost province of Guantanamo and would be shut down province by province as winds picked up across the country as a preventive measure.
Officials and residents, already exhausted by a six-month battle with the coronavirus pandemic and the severe scarcity it has brought, scrambled as Laura bore down to evacuate thousands along the coast and in inland areas vulnerable to flooding.