John B. Curtis

As director of the Potential Gas Agency, John Curtis works with a team of 145 geologists, geophysicists and petroleum engineers in their biennial assessment of remaining U.S. natural gas resources. He is the spokesman and public face of the Potential Gas Committee, and disseminates its vital message both within the industry and to the general public, including legislators and policy makers.

This past year, the PGC wowed the world with its assessments of shale-gas resources. In its year-end 2006 report, the PGC assessed U.S. shale resources at approximately 200 trillion cubic feet (Tcf), out of 1,321 Tcf total. The year-end 2008 report pegged the shale-gas resource at an astonishing 616 Tcf, out of 1,836 Tcf. Suddenly, the U.S. was swimming in natural gas resources.

“The bulk of the increase has come from evaluation of new shale plays and reevaluation of classic plays such as the Barnett and Fayetteville,” says Curtis. “Those have really proven themselves.”

As recently as a decade ago, coalbed methane was considered the last, best hope of the U.S. natural gas business. Now, shale gas is the new savior.

“We have known for a very long time that shale had tremendous gas-in-place volumes, but new technology—and pricing to a lesser extent—have allowed the industry to turn in-place gas into technically recoverable resources, production and proved reserves,” he says.

And that trend is likely to continue. There are a multitude of potential shale plays in the U.S. and Canada that have not been investigated or are just being touched on, he says. While the PGC had a great deal of information on the Fayetteville, Barnett, Antrim, Woodford and Ohio shales in its most recent estimate, it was conservative in assessing the newer Haynesville and Marcellus plays. “In the future, we anticipate more plays being evaluated, and upside potential is good.”

Curtis expects the size of the technically recoverable resource to keep expanding. That resource has been growing for the past 20 years, particularly during the past four years. “We see a further increase in the contribution of shale gas and tight sands to unconventional gas during the coming decade,” he says.

“The gas resources are here; it’s a matter of price, government policy and technology. The industry has done a great job on technology, but the other two factors are largely beyond our control.”

Coalbed methane, the vanguard of the unconventional-gas boom, has flattened in terms of resource growth, however. That’s likely due to both economics and federal land policies. Geologically, there are coal seams that can be investigated, and coalbed methane is not exhausted by any means, says Curtis. “It’s just quieted down at the moment. Shale gas has come on so strong that it is dominating everything.”

Beyond shale gas, methane hydrates loom. One challenge is production methods, and researchers in Japan, Canada and the U.S. are working on solutions. While copious volumes of hydrates exist, they tend to be in such challenging environments as deep water and the Arctic. And, much is locked in rocks of very poor reservoir quality. “It’s not likely in 10 years, but perhaps in 20 years we may have some interesting production from hydrates,” he says.

Curtis has been evaluating resource potential for years, and has seen many changes over a long career. He first worked in the oilfields with Texaco Inc., after completing his undergraduate and master’s degree work at Miami University in 1972 and a tour as an officer in the U.S. Air Force.

After his stint with Texaco, he worked at SAIC, Columbia Gas and Brown & Root Laboratories/Baker Hughes. Having accumulated 15 years of industry experience, in 1989 Curtis completed a doctorate in geology from Ohio State University. The following year, he moved to Colorado School of Mines.

In addition to his role with the Potential Gas Agency, he is a full-time professor and teaches petroleum geology, petroleum geochemistry and petroleum design. He also supervises graduate student research and is director of the Petroleum Exploration and Production Center. He co-directs the CSM Unconventional Natural Gas Institute.

Curtis has devoted abundant time and energy to the broader professional community. He has served on and chaired several professional society and natural gas industry committees. He is widely published, is an accomplished speaker and has volunteered as an associate editor of the AAPG Bulletin for the past 10 years.