In about 18 months the U.S. Geological Survey (USGS) should be able to tell the energy industry, and everyone else, just how productive the Three Forks formation, which lies below the Bakken Shale, might be.
Last October USGS began a two-year study of the Bakken and the Three Forks formation, which lies above it (see Shale Daily, May 24, 2011). Six months in, much work has been done.
"To date, we've looked at a large number of cores from both the Bakken and Three Forks formations, about 50 cores to date from both the USGS Core Research Center and the North Dakota Geological Survey at Grand Forks [ND]," USGS's Stephanie Gaswirth, a research geologist, told NGI's Shale Daily on Wednesday after speaking at the 20th Williston Basin Petroleum Conference in Bismarck, ND.
Core samples also have been taken for geochemical analysis.
Unlike the Bakken, which was scrutinized closely in a 2008 USGS assessment, the Three Forks has not been cored much, Gaswirth said. "There are a much larger number of cores from the Three Forks this time around than there were when this was done the last time in 2008. That's the main reason we're doing this assessment is because the Three Forks was not assessed in 2008, and really given the proven reservoir potential, it needs to be assessed.
"It makes sense to do the Bakken as well because it sits right above [the Three Forks] and there's been a substantial amount of production from that since 2008. Because of that production, we have new geologic information that we can use to get a better estimate."
This time around the USGS is enjoying greater cooperation from the energy industry, which has been more forthcoming with sharing production data than last time, Gaswirth said. "I think people were just more tight-lipped about talking with us [in 2008], whatever their reasons were."
If the Bakken is feeding oil to the Three Forks formation, then when the Bakken ends and the Three Forks continues beyond the extent of the Bakken, will that portion of the Three Forks be productive? That's what USGS wants to know. Results of the research are expected to be released during fall 2013.
"One of the things that we're working on is how much Bakken oil has saturated the Three Forks and how far beyond the limits of the Bakken Shale does this Three Forks have oil in it?" Gaswirth said.