More US Gulf of Mexico operators were removing staff from installations in the region ahead of Tropical Depression Cristobal on Thursday.

On Thursday morning, Anglo-Dutch supermajor Shell said it would reduce non-essential workers at some of its offshore facilities as a precautionary measure.

"There are currently no impacts to our production and drilling operations," a spokesperson said.

Additionally, workers moved from our to the facilities will continue to adhere to the company's existing Covid-19 mitigation measures.

"All personnel will be required to pass our Covid-19 screening process prior to returning to work offshore," the spokesperson said.

Meanwhile, UK supermajor BP said late Wednesday it had begun removing offshore personnel and reducing production its operated Thunder Horse, Atlantis and Na Kika facilities.

In addition, non-essential personnel were being evacuated from BP's operated Mad Dog platform, but production remained unaffected.

"Safety is our top priority and we will continue to monitor weather conditions closely to determine next steps," BP said.

Other operators evacuate

Earlier on Wednesday, Occidental Petroleum and Equinor also said they were evacuating workers ahead of the storm. Equinor also said it would shut in production at its Titan oil platform and remove remaining workers on Friday if the storm continues along its projected path.

An Equinor spokesperson told Upstream there had been no change in the company's approach as of Thursday morning.

Occidental said Thursday that while it was removing non-essential staff, all of its facilities were still operational.

Meanwhile, US independent Murphy Oil said Thursday morning it was also removing non-essential staff from US Gulf operations.

US supermajor Chevron said it had not evacuated any staff and there had been no effect to production at its operated facilities.

BHP and Hess said they were monitoring the storm.

Forecast

As of 10am Central Time on Thursday, the US National Hurricane Center downgraded Cristobal from a Tropical Storm to a Tropical Depression, but said the storm continued to produce heavy rains and life-threatening flooding.

According to the latest forecast, the storm's centre will move over north-west Guatemala and eastern Mexico on Thursday and move back over the southern Gulf of Mexico Friday. It is expected to move over the central Gulf of Mexico on Saturday, and approach the northern Gulf of Mexico coast Sunday.

While maximum sustained winds have decreased to near 35 miles per hour (55 kilometres per hour), re-intensification is expected to begin on Friday.