After Decades of Fracking, We Finally Know How the Fluid Spreads Underground

Given how profound an effect hydraulic fracturing has had on the U.S. economically in recent years, it can come something of a shock to discover how little we know about it.

Blasting water, sand and chemicals into shale rock formations deep underground has unlocked vast hydrocarbon reserves previously considered almost impossible to exploit. Over the past decade, fracking, as the technique is also known, has transformed the country into the world’s largest oil producer, adding supply equal to all the black gold pumped by Saudi Arabia. It has remade America as an exporter both of crude and natural gas, something once unthinkable.

It’s also sparked controversy over environmental concerns that have long dogged the industry. Fracking has been blamed for causing earthquakes in Oklahoma and poisoning groundwater in Pennsylvania. New York and Vermont have banned it.

Much of the controversy is driven by mystery surrounding the fracking fluid itself. Oil-services giant Schlumberger Ltd. once described fracking as employing “brute force and ignorance.” But for the first time, we have a clear picture of how the fluid used in fracking travels underground.

The extraction process begins when a well is drilled vertically about a mile into oil-rich shale rock, then turns and carves horizontally through the shale zone for another mile. The well is encased in metal tubes for protection.

A combination of water, sand and chemicals is then pushed down the well at high pressure to fracture the shale at various equidistant points along the wellbore.

The thinking went that in a perfect frack, the fluid would be distributed in regular, even increments for each stage of hydraulic fracturing.But data from Deep Imaging, a small oilfield technology company in the suburbs of Houston, seems to confirm what many oilfield engineers have feared but couldn’t prove: a typical frack comes with lots of uncertainty—and bears little resemblance to the ideal.

Deep Imaging uses an electromagnetic field to detect the flow of fracking fluid through the Earth’s crust—and their results show a chaotic scene where fluid spreads unpredictably. Areas of rock affected by fracking are both considerably larger and shorter than planned. Take this well in Oklahoma as an example. In some cases, fluid seeps into areas that have already been fracked, meaning there’s less oil and gas available to extract. When fluid doesn’t seep as far as intended, valuable oil and gas is left behind.

When wells are dug in close proximity, fluid that spreads beyond the intended range of the frack could interfere with a neighboring well—leaving both compromised. In this case, fluid from multiple fracks seeped into previously fracked areas, as well as space drilled by a neighboring well.

Fracking has minted a string of billionaires and created modern-day oil booms in North Dakota and West Texas. Deep Imaging says their data can help the industry drill wells more strategically to maximize production and profits.

But decades of drilling without a detailed picture of how fluid spreads means many existing wells are inefficient. And oil and gas that has been left behind by imprecisely drilled wells is now inaccessible with current technology.

The new data could also inflame those who seek more oversight over fracking, as there are still questions left unanswered. Deep Imaging’s technique does not measure how far the fluid travels vertically, so it wouldn’t be possible to detect if fluid is seeping up high enough to enter underground water sources.

While the push for greater regulations over fracking has mostly died down from state legislatures, the issue has gained steam nationally. Massachusetts Senator Elizabeth Warren said in a Tweet last month that if elected, she will ban fracking “everywhere” on the first day of her presidency.

Such a move would be “incredibly bullish” for the price of natural gas in the U.S. and oil around the world, according to analysts at Sanford C. Bernstein. But Credit Suisse says even just restricting the well-completion technique on federal lands seems unlikely. William Featherston, an analyst at Credit Suisse wrote in October that taking a frack ban to private land would need an act of Congress, making such a move “untenable.”