Dr. Roger Moore Butler, P.Eng., the inventor of steam-assisted gravity drainage — a process that revolutionized oil sands development — passed away peacefully on May 19 at the Foothills Medical Centre in Calgary. He was 77.

“If I hadn’t thought of it, someone else would have,” he once said of his invention.

Dr. Butler was born Oct. 14, 1927 , in Ilford , England . He lived in Canada during the Second World War and returned to England where he studied chemical engineering. He earned his PhD in chemical engineering at London ’s Imperial College of Science and Technology in 1951.

He returned to Canada and taught chemical engineering at Queen’s University in Kingston , Ont., and joined Imperial Oil in 1955. He worked in the petroleum industry with Imperial in Sarnia , Ont., New York and Calgary until the end of 1982.

Dr. Butler then became director of technical programs for the Alberta Oil Sands Technology and Research Authority until he accepted the Endowed Chair of Petroleum Engineering at the University of Calgary from its inception in 1983 until the end of 1995. Following his retirement from the U of C, he was founder and president of GravDrain Inc., a research and consulting company for the heavy oil industry.

Dr. Butler’s experience covers a wide range of petroleum industry research, engineering and development activities, including heavy oil and tar sands production, refining, computer control and transportation.

During 1987-88, he was a distinguished lecturer for the Society of Petroleum Engineers and spoke worldwide about horizontal wells. He made a second lecture tour for the SPE in 1992-1993 and spoke on steam-assisted gravity drainage, the process he invented in 1978.

In 1987 he was awarded the RS Jane Memorial Lecture Award, the premium award of the Canadian Society for Chemical Engineers. Dr. Butler authored or co-authored over 100 scientific papers and patents, and two books.

Dr. Butler’s passions were many and included his family, science, mathematics, computers, electronics, short- wave radio, sailing, travel, painting and woodworking.

Dr. Butler is survived by his wife Joyce of 51 years; sons Allen and Peter, and daughter Mary and their families; and five grandchildren.