FEATURE-Oil groups turn focus back to traditional fields | Reuters

The six-metre high red, blue and gold ball recently painted on the side of the Alwyn alpha rig is the largest Total logo in the world -- a sign of Big Oil's growing focus on its heartlands.

Across a 73-metre steel bridge, the Alwyn bravo platform, its blastwalls glistening in the Spring sunshine, processes 100,000 barrels equivalent of oil and gas a day.

Even though it is well past its peak, the North Sea accounts for 25 percent of Total's (TOTF.PA) production and the French oil major's investment in the area is growing.