Prayers are usually reserved for the needy, downtrodden or powerless.

But the US state of Oklahoma has turned that notion on its head, by calling on citizens to pray for the world's biggest industry - the oil sector.

Oil is one of Oklahoma's leading industrial sectors. Photo: Shutterstock

The call to prayer will culminate on October 13 in Oilfield Prayer Day, marked by a special breakfast event in Oklahoma City.

Oklahoma governor Mary Fallin declared the prayer day with an executive proclamation. "Whereas Oklahoma is blessed with an abundance of oil and natural gas ... [and] Christians acknowledge such natural resources are created by God," the proclamation read, "Christians are invited to thank God for the blessings created by the oil and natural gas industry and to seek His wisdom and ask for protection."

With oil prices down, the industry - a big player in Oklahoma - is hurting.

“We're asking churches all over Oklahoma to open their doors, put on a pot of coffee and pray for the oil field, and not only for the oil field but the state, because the economy of our state is so connected to the oil field," Reverend Tom Beddow of Ada, who also coordinates the Baptist General Convention of Oklahoma's Oil Patch Chaplains ministry, told NewsOK.

Despite lower prices, the sector as a whole remains the biggest in the world, with seven out of the top 10 revenue companies coming from the fossil fuel industry.