The recent oil and gas industry downturn has muted the discussion of fracking that reached a fevered pitch only a few months ago. In the world of fossil fuels, one thing is nearly certain; what goes down will surely come back up. When the value of oil and gas gets higher, and the industry gets busy, the vigorous debate surrounding fracking will be front page once again.
Industry insiders, myself included, can't help but cringe when we hear our local news anchor call oil and gas "the fracking industry". To be sure, there is such a thing but it refers specifically to the companies that do that type of work and it is only a small, albeit important, part of the bigger picture. A solid understanding of what the process is by people on all sides of the issue, would go a long way in moving the overall conversation forward.
The term fracking is short for fracture stimulation. Somehow that just doesn't have the same ring. Despite all the attention lately, the process is really nothing new. Fracture stimulation has been around since the 1940's and, although the technology has changed, the basic principles have stayed pretty much the same. The importance of fracking to the recovery of oil and gas from shale can't be overstated but it is just one part of the bigger picture.
After the well is drilled and prepared, a tool called a perforating gun is lowered into the well bore. The gun, as the name would suggest, shoots projectiles through the pipe, that encases the well, and into the rock or shale formation. The projectiles create holes deep into the rock and tiny cracks form around the holes. Once the tool is removed, the well is prepared for the next step which is the fracture stimulation process.
Powerful industrial pumps, capable of creating pressure in excess of 10,000 pounds, are connected to the well. The equipment is used to force a mixture of water, sand and a small amount of other chemicals down the well bore and into the formations, through the holes created by the perforating gun's projectiles. The pumped water exerts pressure on the surrounding rock and widens the small cracks.
In industry terms, the sand is call a propant. Just like the name sounds, it prop open the newly formed fractures so the oil and/or the gas can flow back through. The sand is strong enough to hold the weight of thousands of feet of dirt and stone, but porous enough to allow liquid to pass through. The small amount of chemicals that are mixed with the water and sand, lubricates the pipe and keeps the mixture from clumping into a sludge that can't be forced down the bore.
A well is broke into zones, or areas where pockets of liquids have been found. Each zone is perforated and fracked, starting at the bottom and moving upward. After each is complete, a plug is set just above it, to prevent the pressurized liquids from shutting the process down for the next zone. When the frack is complete, the plugs are drilled out and the well begins to flow.
Fracking has been held up as a new and mysterious process when, in fact, it is neither. It is a very important part of recovering gas and liquids from both tight rock and shale formations but it is only a part even though it has been credited with bringing about the most recent boom. As surely as the oil and gas prices will come back up, the fracking debate will once again be front and center. The next time you hear a heated discussion on subject, you can agree or disagree but at least you will know just what it is you are arguing about.