SemGroup® Corporation (NYSE:SEMG) moves energy across North America through a network of pipelines, processing plants, refine ... ry-connected storage facilities and deep-water marine terminals with import and export capabilities. SemGroup serves as a versatile connection between upstream oil and gas producers and downstream refiners and end users. Key areas of operation and growth include western Canada, the Mid-Continent and the Gulf Coast. SemGroup is committed to safe, environmentally sound operations. Headquartered in Tulsa, Okla., the company has additional offices in Calgary, Alberta; Platteville, Colo.; and Houston, Texas. read more