“The important part was we collected all the samples we need to address our primary questions,” Dugan said. “When we’re done drilling and we pull our equipment out, the holes collapse back in and seal themselves up.”

Now, scientists are studying the reservoir in finer detail, including any microbes, rare earth elements, pore space — which can help researchers better estimate the reservoir’s size — and the age of the sediments, which will help narrow down when it formed. More definitive results about how and when the reservoir formed are expected in about one month’s time, Dugan said.

“Our goal is to provide an understanding of the system so if and when somebody needs to use it, they have information to start from, rather than recreating information or making an ill-informed choice,” he said.