This is a former EVP of Mobil. Link:
Louis Allstadt: The fracking that’s going on right now is the real wake-up call on just what extreme lengths are required to pull oil or gas out of the ground now that most of the conventional reservoirs have been exploited – at least those that are easy to access.
Ellen Cantarow: So could you describe the dangers of this industry?
LA: First of all you have to look at what is conventional oil and gas. That was pretty much anything that was produced until around 2000. It’s basically a process of drilling down through a cap rock, an impervious rock that has trapped oil and gas beneath it – sometimes only gas. If it’s oil, there’s always gas with it. And once you’re into that reservoir – which is really not a void, it’s porous rock – the natural pressure of the gas will push up the gas and oil. Typically you’ll have a well that will keep going 20, 30 years before you have to do something to boost the production through a secondary recovery mechanism. That conventional process is basically what was used from the earliest wells in Pennsylvania through most of the offshore production that exists now, that started in the shallow water in the Gulf of Mexico and gradually moved down into deeper and deeper water.
Now what’s happened is that the prospect of finding more of those conventional reservoirs, particularly on land and in the places that have been heavily explored like the US and Europe and the Middle East just is very, very small. And the companies have pretty much acknowledged that. All of them talk about the need to go to either non-conventional shale or tight sand drilling or to go into deeper and deeper waters or to go into really hostile Arctic regions and possibly Antarctic regions.
Methane release: fracking the planet’s future
So when you talked about “the race for what’s left,” that’s what’s going on. Both the horizontal drilling and fracturing have been around for a long time. The industry will tell you this over and over again – they’ve been around for 60 years, things like that. That is correct. What’s different is the volume of fracking fluids and the volume of flow-back that occurs in these wells. It is 50 to 100 times more than what was used in the conventional wells.
The other [difference] is that the rock above the target zone is not necessarily impervious the way it was in the conventional wells. And to me that last point is at least as big as the volume. The industry will tell you that the mile or two between the zone that’s being fracked is not going to let anything come up.
But there are already cases where the methane gas has made it up into the aquifers and atmosphere. Sometimes through old well bores, sometimes through natural fissures in the rock. What we don’t know is just how much gas is going to come up over time. It’s a point most people haven’t gotten. It’s not just what’s happening today. We’re opening up channels for the gas to creep up to the surface and into the atmosphere. And methane is a much more potent greenhouse gas in the short term – less than 100 years – than carbon dioxide.
Go read it all.