"Stimulating oil and gas activity to the west of Scotland could create employment and further increase the longevity of the industry in the country," Ewing said in a statement Sunday.
Scotland holds a referendum for independence in September. The government says it could support itself with oil and gas revenue while powering its economy with renewable energy resources.
Ewing said the long-term future of the oil and gas industry in Scotland is bright, with a potential to support hundreds of thousands of jobs. Many of the gains would come only if voters get in line behind the referendum, he said.
"Only with independence will the Scottish Government have the full economic powers to stimulate exploration activity in Scotland's waters to fully develop the country's oil and gas resources," he said.
Geologists at the University of Aberdeen said that, while much of the North Sea has been in production for decades, most of the area off the western coast remains unexplored.
Ewing in May said higher taxes for work in the North Sea may complicate Scottish energy ambitions. The British government says the regional economy in general would be better off if the United Kingdom remained united.