By Randy Fiedler

As the world searches frantically for newer and more sustainable sources of energy, geologists remain committed to finding better ways to locate and extract new supplies of the fossil fuels that have powered our society for more than a century and a half.

While much of the world’s remaining reserves of fossil fuels are hidden away inside geological formations that are increasingly difficult and expensive to exploit, Baylor University geology faculty and students are taking part in research that might one day make those sources of oil and gas more accessible.

The majority of faculty in Baylor’s geology department are teaching and researching in areas not primarily concerned with oil and gas, such as geophysics, paleoclimatology and sedimentary and structural geology, but the professors and students who are interested in the oil industry have made the University’s popular Applied Petroleum Studies Program respected throughout the industry.

Dr. Stacy Atchley, professor of geology, chairs Baylor’s geology department and came to the University after a successful career in the oil industry. In his view, economic and technological factors are driving today’s renewed interest in the study and exploration of fossil fuels.

“Ten years ago I would have said that while there is a lot of oil left in the ground, it’s contained in reservoirs where you can’t easily extract it,” Atchley said. “But with modern technological advancements, oil and gas are being recovered from reservoirs that 10 years ago I didn’t think possible. That’s what has caused North America to be one of the world’s current leading oil producers.”

Atchley said that while most oil wells in the past were drilled vertically into deposits that flowed easily, much of the considerable remaining supply of North American oil and gas is located in “unconventional reservoirs” composed of rocks with tiny pores that make extraction virtually impossible using traditional means.

To recover oil and gas from these unconventional reservoirs, geologists are now using techniques such as horizontal drilling and hydraulic fracturing –– more commonly known as “fracking.”

“What oil companies do is orient the wellbore [drilled down into the ground] horizontally over a great distance, perhaps a mile or more, rather than vertically within unconventional reservoirs” Atchley said. “They will then inject fluid into the unconventional reservoir at a very high rate, causing the rock to spontaneously fracture.”

The many fractures that are created by “fracking” serve as flow conduits that allow the oil and gas to be produced at rates that are economically feasible.

One example of an unconventional oil-bearing formation is the Cline Shale, which underlies a 10-county area of west Texas near Midland. Some industry estimates say it may contain as much as 30 billion barrels of oil.

Two recent Baylor geology Master’s students, Brian Crass and Kieron Prince, were sponsored by the Tulsa-based oil company Nadel and Gussman to research and analyze their acreage in the Cline Shale.

“They’ve known for a long time that there is oil there, but the technology has not been advanced enough to extract it and make it economical. The type of rock that it is in is very tight…but by using fracking and horizontal drilling, you are able to produce economical amounts of oil,” Crass said. “Kieron and I were hired to go in and look at core samples, describe the core and then with that information –– combined with (the company’s) data –– come up with some way to predict whether the Cline was going to be productive or not in any given area.”

The students used core samples –– continuous cylindrical sections of rock collected during the drilling of a well that show the different rock layers underneath –– from a single well to describe the type and quality of the rock found at each depth. They then designed a computer model that took their findings and applied them across a broader area of the Cline Shale.

“Our computer tool was designed to give the company an estimation of where the sweet spots are,” Crass said. “They would use it to predict areas where they might want to (purchase) leases, or areas where maybe they already had leases that didn’t look (as promising for oil).”

Using computer models to search for new oil deposits happens to be an area of expertise of Baylor’s Dr. Scott James, assistant professor of geology. James came to the University after an industry career that included the design and use of computer models that evaluate the effects of groundwater flow on nuclear waste disposal facilities.

Most recently, James is conducting research at Baylor funded by the Canadian energy company RII North America Inc., aimed at increasing the amount of oil that can be extracted from Canada’s sizeable unconventional oil reserves.

“Typically when you produce oil from a formation it’s considered depleted when you remove 5 percent of the oil,” James said. “We are seeking enhanced oil recovery technologies to access an additional 30 percent.”

The Canadian formation James is concerned with contains “heavy” oil –– crude oil that is incredibly thick and as a result does not flow easily through rock. The traditional method to heavy oil from such formations is called Steam Assisted Gravity Drainage, or SAGD for short.

Using SAGD technology, a company first drills a well into a reservoir that contains heavy oil. Then, a large boiler on the surface heats water to produce steam that is introduced at high pressure into the wellbore. The steam will heat the heavy oil so that it will flow to the surface much easier.

SAGD is commonly applied to a pair of horizontal wells placed one above the other. The steam is pumped through the upper well, which heats the oil that is then captured in the lower well.

However, SAGD technology has some significant drawbacks. Boiling the water on the surface emits carbon dioxide to the atmosphere, and when the water is injected below ground, large quantities of saltwater and natural gas are created as byproducts that must be disposed of. In addition, the technique is inefficient because the steam created on the surface loses as much as 50 percent of its heat energy due to cooling on its way underground.

James is researching a new technology developed by RII called downhole steam generation that promises to eliminate many of SAGD’s drawbacks.

“Instead of generating the steam at the surface, we’re now generating steam within the oil reservoir itself,” James said. “We put equipment down an existing well with three separate coaxial tubes –– one carrying methane or natural gas, one carrying oxygen and the third carrying water. We ignite the system underground, burning the natural gas and oxygen to boil the water and create steam. Every bit of the heat generated is delivered right to the pay zone.”

The new method leaves the released carbon dioxide underground, instead of introducing it to the atmosphere. The saltwater that is produced as a formerly unwanted byproduct does not end up above ground, but instead is recycled and made into the steam used underground.

James creates the computer models that will tell RII how to optimize the operation of the system and remove the largest amounts of oil.

“The beauty of downhole steam generation is its simplicity. There are very few moving parts, it’s environmentally friendly and we get 100 percent thermal efficiency,” James said. “There are a lot of benefits to it.”

Canadian oil fields have also been rich sources of research for Atchley and his students. In 2014, he and two doctoral students –– Harlow Hunter and Caitlin Leslie –– did important work for the Canadian firm GLJ Petroleum Consultants.

“They asked us if we could do a detailed geological assessment of a conventional reservoir in east central Alberta,” Atchley said. “The reservoir has a lot of really large pores, and the oil could conceivably flow easily through it, but oil in that area has been degraded to tar. The reservoir has never produced because of the tar it contains, so GLJ asked us to characterize the reservoir and the associated tar to determine those areas most suitable for potential production.”

Instead of being limited to using core samples from a single well, as the Baylor students studying the Cline Shale were, Atchley and his students were able to make use of almost 100 core samples over a wide area.

“We matched up all that core data with information from well logs, and then used our software in the Baylor petroleum lab to create maps over a hundred square mile area,” Harlow said. “We made 12 maps and 12 cross sections. It took us an entire semester to work on it, and we came up with a recommendation –– saying these are the best zones, with the best rock types we think there are. We found a lot of in-place oil reserves up there.”

“The company loved it,” Leslie added. “They thought we did good work and were pleased with the results.”

Atchley has prepared a journal article describing his team’s work and presented their findings at a conference in Banff, Alberta, this past summer.

The kind of hands-on research that Baylor graduate students interested in petroleum geology are able to do in American and Canadian oilfields is helping Baylor students to be more marketable than graduates from many other universities that don’t provide students with applied research opportunities.

“What’s unique about Baylor is that we’re leveraging our students’ geoscience skills towards oil and gas production. Most schools don’t do that,” Atchley said. “It might take someone working for an oil company two to three years to get the experience and the skills Baylor students graduate with. Our students stand out, and we’re having great success in placing them.”