By DavidA.  Hill, Executive Editor

RIFLE, Colorado — According to an expert, as much as 95 percent of the oil and gas wells in the world are now dependent on the technique known as hydraulic fracturing, because the easily reached petroleum reserves have basically been used up.

“By definition, the low-hanging fruit in the oil and gas industry is gone,” said Jennifer Miskimins, associate professor of the Petroleum Engineering Department at the Colorado School of Mines in Golden for the past eight years.

Miskimins explained in her talk before the Garfield County(Colorado) Energy Advisory Board that most of the gas and oil that is left is deeper in the ground and “entrained,” or embedded in various types of rock formations. And once a fluid is so entrained, she said, it tends to stay put unless jarred loose and permitted to flow by industrial intervention.

John Colson of the Post-Independent, a Glenwood Springs, Colorado-based newspaper, reported on the gathering, during which Miskimins reviewed the history of the fracking process. Key from our perspective were these comments:

Before hydraulic fracturing was invented in the 1940s, “Most of these reservoirs [meaning formations like those in Garfield County] we never dreamed we’d be producing from.”

She said that because of the nature of the geology involved, and the fact that deeply buried rock is under enormous pressure, the fractures created by the process will not “travel” to the surface and release either the chemicals introduced by the frac’ing process, or the hydrocarbons unearthed by the drilling.

And, she said, the thing to worry about is not that the chemicals get released, but the hydrocarbons — the chemicals that make up oil and natural gas.

“There’s nothing in frac’ing fluids that’s any more dangerous than the hydrocarbons we’re producing,” she declared, adding that the chemicals added to the fluids are in “very small volumes” compared to the gas produced.

Some in the meeting pressed Miskimins about the the possibility of well-bore failures, seepage of chemicals into the surrounding ground water and other potential hazards involving the fracking process.  She responded by saying those were questions best answered by the companies or the government overseeing the industry.

“Universities can’t do it,” she said of those issues, due to a lack of funding.