Opus Petroleum Engineering Ltd. has provided formation water interpretation services to the oil and gas industry since 1986 when the first version of the Opus Handbook “Formation Waters of Western Canada" was published. In 1992 the "Opus Handbook" was upgraded and British Columbia and Saskatchewan were added. Most of the oil companies in Calgary have at least one copy of this useful catalogue.

The principals of Opus Petroleum, Richard Johnson and Susan Johnson, have been teaching courses on formation water interpretation and consulting to the oil industry on oilfield water identification since 1990.

Richard Johnson graduated from the University of Saskatchewan as a Geological Engineer in 1963 and has been working as a geologist and then as an engineer for various companies in Western Canada. He has been President of Opus since 1984.

Susan Johnson graduated from the University of Calgary with a Bachelor of Education degree in 1970. She has been working as an engineering technologist for various companies in Western Canada since 1971 and currently works full-time as a water interpretation consultant for their joint company, Opus Petroleum Engineering Ltd.