Thursday, March 15, 2012

Dr. Strangegas or: How I Learned To Stop Worrying And Love The Fracking

Venkman:      This city is heading for a disaster of Biblical proportions.
Mayor:           What do you mean, “Biblical”?
Stantz:            What he means is Old Testament, Mr. Mayor, real wrath of God-type stuff.
Venkman:      Exactly.
Stantz:            Fire and brimstone coming down from the skies!  Rivers and seas boiling!
Spengler:        Forty years of darkness!  Earthquakes, volcanoes . . .
Zeddemore:    The dead rising from the grave!
Venkman:      Human sacrifice, dogs and cats living together, mass hysteria!
—Bill Murray as Dr. Peter Venkman, Dan Aykroyd as Dr. Raymond Stantz, David Margulies as the Mayor, Harold Ramis as Dr. Egon Spengler, and Ernie Hudson as Winston Zeddemore in Ghostbusters

Some of you in areas that are new to hydrocarbon (oil and gas) production need to get a grip and learn to embrace your new-found resource base.

I see the media-fueled hysteria over the energy industry’s use of a technique called “hydraulic fracturing” (“fracking,” in industry parlance) continues unabated.  Drinking water is fouled.  Earthquakes are shattering the countryside.  Big Oil is trying to ruin the environment and kill everyone.  And you know it’s all true, because Big Oil is doing it, and we know everything Big Oil does is evil by definition, right?

As a lifelong Texan and someone whose professional background has largely focused on oil and gas production, I have one word in response:


Time for some remedial education, because all this hysteria stems from a fundamental ignorance of how oil and gas wells are drilled, and how fracking works.

First, let’s consider how an oil or gas well is constructed.  Contrary to the Jed Clampett legend, you can’t just shoot your rabbit gun into the dirt and up from the ground comes a-bubblin’ crude (or gas).  You have to drill a well, and there’s a lot more to that than just poking a hole in the ground.  The drillers drill to the desired depth, and then a steel tube (“casing”) is inserted and cemented in place with concrete.  This is done to seal off the wellbore from any groundwater reservoirs that may have been penetrated in the process of drilling the well.  Typically a second pipe (“production tubing”) is run through the casing, and then a shotgun-like device is set off at the depth of the expected producing zone to penetrate (“perf”) the tubing, casing, and cement, allowing the hydrocarbons to flow into the well.  With this type of construction, groundwater is insulated from the hydrocarbons by two layers of steel pipe, plus a layer of concrete.

Second, let’s understand a little about oil and gas reservoirs (the geological formations from which oil or gas is obtained).  You may not know this, but oil and gas wells aren’t drilled into gigantic hollow places under the earth like an underground tank you can just tap with a straw (at least not anymore—that low-hanging fruit was all found and drained long ago).  Instead, oil and gas sits underground trapped in tiny pores in layers of porous rock (think of a kind of stone sponge).  The well is drilled into that layer of porous rock, “perfed” at that level, and with luck the natural underground pressure will drive the oil or gas from the rock, through the perfs, and into the production tubing.  When the natural pressure is not enough or becomes depleted, various pumping or reinjection techniques are employed either to suck or push the hydrocarbons out of the rock and into the well.

But sometimes the rock in which the hydrocarbon—in this case, typically natural gas—is trapped is not porous enough to permit the gas to flow into the well.  This is where fracking comes in.  The driller will pump water down the well at high pressure.  That water exits the well underground through the perfs, and creates a network of small cracks in the rock—how those of you in states long-accustomed to miners digging hundreds of miles of gigantic subterranean tunnels can be worried about this escapes me—through which the gas can now flow.  Mixed in that water are certain chemicals designed to facilitate flow, and either sand or tiny ceramic beads to help keep the cracks from closing.  The water is then pumped out of the well and disposed, and with any luck the well will now flow.

Let’s be clear about something before I move on.  This technique is not controversial, and it is not new.  It has been around since the 1940s, and most gas wells drilled in the last several decades were completed with some form of fracking procedure. 

What’s new is the way it’s being used with what is called “shale gas.”  The energy industry has long known that there were ENORMOUS gas reserves trapped in layers of shale rock deep beneath the surface.  The problem was the nature of shale made it uneconomical to produce.  Shale typically resides very deep—8,000 to 10,000 feet or deeper—and often in relatively thin layers (think of a parfait with a very thin layer of chocolate only near the bottom).  What this means is that the producing zone may be as little as 20 feet thick, which isn’t much area to produce in a 10,000 foot well.  And because shale is relatively non-porous, it requires fracking in order to release the gas it holds trapped.  But the cracks from a frack job only extend a couple hundred feet from the wellbore.  As a result, to get to shale gas, you had to drill an extremely expensive deep well, and you could only produce what was trapped within a short radius from a thin layer of shale.  You couldn’t produce enough gas that way to make the well worthwhile.

Modern drilling technology has changed that equation.  Drillers are now able to drill horizontally, meaning they can drive down to the desired depth, then bend the wellbore to run parallel to the productive zone.  Instead of just penetrating the thin layer of shale at a single point, they can now get to the shale and then run hundreds of feet along it.  This allows them to do many perfs, many fracks, and produce from a much broader area with a single well, making the shale gas now economical to access.

But Rusty, what about the people with fire coming out of their kitchen faucet?

The characteristics of shale gas and the fracking technique raise a few important difficulties for those who now want you to be all freaked out about all this.  As I mentioned, these shale deposits sit DEEP, typically 8,000-10,000 feet or more below ground.  The groundwater you drink—if you drink well water—is much shallower.  Private wells are usually no more than 50 to 100 feet deep.  Even deep municipal wells are not much more than 1,000 feet.  This means there is more than a mile of earth between any groundwater and the shale that’s being fracked.  Because fracking doesn’t extend more than a couple hundred feet from the wellbore, it simply can’t create a pathway from where the hydrocarbons and fracking fluid are to where the groundwater you’re drinking is.  Moreover, that mile of earth will always include a cap layer of impenetrable rock—otherwise, the gas would never have become trapped there in the first place.    

I don’t know what’s (allegedly) coming out of your tap, but it didn’t come from hydraulic fracking.

Nor is fracking responsible for the ground shaking in places like Ohio.  The kinetic energy of a frack job is less than that of seismic testing commonly used for decades to locate geologic formations, and at a depth of nearly two miles, it has less impact on surface stability than your basic 18-wheeler.  Moreover, the volumes, pressures, and duration are far less with fracking than with the longstanding practice of reinjecting the saltwater that is produced from many oil and gas wells.  What you are seeing in Ohio is the media (deliberately?) confusing hydraulic fracking with the latter practice.  A saltwater injection well, if improperly placed on a fault line, can cause seismic activity, and this is almost certainly what has happened in Ohio.

Hydraulic fracking is not poisoning your water, and it is not going to shake your house down.  What it is doing is allowing the energy industry to tap the equivalent of hundreds of millions of barrels of oil in the form of domestic reserves of clean-burning, cheap natural gas.  In the process, it’s creating thousands of jobs and generating billions of dollars in tax revenues.  And, yes, it’s also turning some of your neighbors who were smart enough to hang onto their mineral rights into millionaires, and what’s wrong with that?  

We seem to have done pretty well with it here in Texas, and we haven’t blown up, fallen into the Gulf of Mexico, or spawned generations of children with three eyes. 

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