John E. Clark

Rival Energy Ltd. engages in the exploration of oil and gas. The company was founded on June 16, 2003 and is headquartered in Calgary, Canada.

Circle Energy, Inc. (Canada) is an oil and Canadian gas field exploration company. The private company is based in Calgary, Canada. Circle Energy, Inc. (Canada was acquired by Rider Resources Ltd. on December 04, 2001 for $3.15 million.

Numac Energy (TESO), Inc. explores for and produces oil and gas. The company is based in Calgary, Canada. Numac Energy (TESO was acquired by Anderson Exploration Ltd. on February 15, 2001 for $508.22 million.

Part of BP Plc, Dome Petroleum Ltd. is a Canadian company that explores and produces crude oil and natural gas. The company is based in Calgary, Canada. Dome Petroleum was acquired by Amoco Corp. on September 29, 1988 for $4,198.71 million.

Pioneer Natural Resources Canada, Inc. explores and mines for oil and natural gas. The company is based in Calgary, Canada. The Canadian company is ultimately controlled by the Emirate of Abu Dhabi (United Arab Emirates). Pioneer Natural Resources Canada was acquired by Abu Dhabi National Energy Co. PJSC from Pioneer Natural Resources Co. on November 27, 2007 for $508.55 million.