Researchers at the Oak Ridge National Laboratory (ORNL) in Tennessee have developed a new analytical approach that could make oil and gas extraction from shale formations more economical and efficient.
The team combined two existing statistical models and applied them to publicly available geographic data to accurately characterize the availability of hydrocarbons in five, high-producing shale plays in the U.S. and Canada. The research was published in the Journal of Natural Gas Science and Engineering.
The project characterized Eagle Ford, Utica and Colorado shale formations, as well as the Banff and Exshaw shale plays in Alberta, Canada.
“Mid-size oil and gas companies, plus those outside of industry, could leverage this method to reduce overall production, extraction time and cost and the potential of environmental disturbances,” said Joanna McFarlane, a research chemist in the ONRL Energy and Transportation Science Division.
McFarlane said the technique uses regression models to explore correlations between predictor and response variables. The research showed the technique was more accurate in determining potential oil production than gas production.
The research paper said oil production parameters were better predicted, based on correlations between macroscopic variables. However, microscale petrographic characterization is needed for modeling gas-producing shales.
McFarlane said the modeling study is based on statistical algorithms for principal component analysis (PCA) and partial least squares regression (PLS)—analytical techniques available to anyone and used in fields ranging from finance to healthcare.
“The interesting thing is just what is available publicly, what can be used and what is missing,” she said.
McFarlane noted that the availability and quality of data improves the accuracy of the analysis, which is why ONRL is interested in advancing the research by collaborating with state agencies, universities and industry that have access to core samples and data. Chesapeake Energy Corp. has provided the ONRL researchers with core samples from the Marcellus, Utica and Eagle Ford shale plays.
McFarlane answered additional questions from North American Shale Magazine about the ONRL research.
Where did you obtain the data used for your research?
Our investigation was limited to—with the exception of some of the data from Chesapeake—publicly available information. Some of it’s from states. Some states have extensive data bases for production and some states do not. Probably the largest part of the effort was digging through and seeing what was available.
Why does the analytical technique work better for oil than it does for gas?
We attributed that to the fact that we looked at the gas in the shale and how it’s associated with porosity. The location of the gas seems to be determined by the very small-scale structure characteristics of the rock and the hydrocarbons within the rock. That data is hard to get and it’s very expensive. Certainly gas producers may have some of that information and detailed characterizations of the rock, but it’s not publicly available.
What does the future hold for this research?
We’re hoping that the work will continue and that there’ll be support. It would be nice to foster a collaboration with places that have a lot of samples, a lot of data and are interested in some predictive analysis. The samples themselves and the data on the samples are a precious resource that should not only help analysis, but also help develop tools that increase production from different strata, depending on how extensive the sampling that’s taken place.
What does ONRL have to offer government and industry organizations interested in research collaborations?
We have some interesting tools here. We have neutron scattering that can penetrate the shales and it’s particularly sensitive to the hydrocarbons. There are two places in the country that do it and they both have a nuclear reactor. There’s us and the NIST facility in Maryland—the National Institute of Standards and Technology. It’s a Department of Commerce lab. Here at Oak Ridge we also have the nuclear reactor, but we also have a spallation neutron source that provides neutrons. We’ve got modeling efforts, we’ve got geochemists, material scientists, metallurgists and sensor specialists. Many have worked with the oil and gas industry and partners.
How can industry collaborate with ONRL on this type of research?
We like to collaborate with industry on issues associated with oil and gas production. There’s a number of ways of doing it. Industrial partners can come use some of our facilities or they can work through a cooperative research and development arrangement. There’s quite a bit of flexibility here at the lab for collaborative work. Often when the Department of Energy issues a call for research proposals, it encourages collaboration with universities and with industrial partners. It’s highly encouraged and often required. I’d highly encourage people to get involved to see what’s available here.