EnergyFactor By ExxonMobil | Pespectives has a new home

Facts on the hydraulic fracturing process

A couple weeks ago, I pointed to a U.K. Parliamentary study that found that hydraulic fracturing – a method that’s enabling greater production of natural gas in shale and other formations – poses no more risk to the environment or water supplies than any other oil and gas production technique.

What’s most important about hydraulic fracturing (or “fracking”), the study found, is ensuring that proper well design and water-handling procedures are rigorously applied at every well.

The finding is just the latest confirmation of what the U.S. Ground Water Protection Council and others have found in their studies of hydraulic fracturing:

“Taken together, state and federal requirements, along with the technologies and practices developed by industry, serve to protect human health and help reduce environmental impacts from shale gas operations,” the Ground Water Protection Council said in a primer prepared for the Department of Energy in 2009.

But public questions remain, and I think many people might be wondering, “So what exactly does ‘proper well design’ mean?”

To answer that question, we recently developed an animation to show how a natural gas well is drilled, the safety measures that are in place to protect groundwater, and what actually takes place during hydraulic fracturing.

You can take a “tour” of the well by playing the video here, or you can view it on ExxonMobil’s YouTube channel. Let’s walk through the basic phases of natural gas production:

  • Preparing for drilling (4 to 8 weeks): This phase involves securing a drilling rig, conducting final tests and environmental analyses, and securing all permits to ensure drilling is done in accordance with regulations. This is also the time we use to implement our own safety and operational plans on top of those required by the government – such as planning for proper management of the project, ensuring plans incorporate responsible practices, and reviewing procedures with employees and contractors.
  • Rig work (4 to 5 weeks): This involves constructing the drilling rig and drilling the well. As professionals drill the well, they install a series of protective steel-and-cement layers that maintain the integrity of the well and protect the surrounding formations. In the upper part of the well, multiple layers of cement and steel casing are installed to create an impermeable barrier between the well and groundwater zones. Drillers also use casing deeper in the well to ensure its integrity and to isolate natural gas formations from the surrounding areas. Engineers and technicians test and monitor each layer of casing and cement to ensure the integrity of the well and the quality of the protective casings.
  • Hydraulic fracturing (2 to 5 days): Hydraulic fracturing is a technique used relatively briefly during the well completion process. It often takes place a mile or more below groundwater supplies. Shale rock has gas trapped in pores smaller than the width of a hair, so we must create a network of small fissures in the rock to release the gas. This involves injecting a mixture of 90 percent water, 9.5 percent sand, and 0.5 percent chemicals (that in part prevent bacterial growth and reduce friction) into the well at high pressures to keep the fissures open, which allows the gas to flow. Again, the activity is continuously monitored. Experts monitor data such as injection pressure and flow rates during the process to ensure that everything is going according to plan.
  • Producing natural gas (25 to 40 years):  Once a well is drilled and completed over the course of a few months, it is ready for production. Everything is dismantled except for a four-to-six-foot well-head and the local processing facilities that connect to gas lines that eventually run to the national distribution network.  A natural gas well can produce gas for up to four decades, and all the while it’s monitored to ensure continual well integrity.

While public discussion is focused on the safety of hydraulic fracturing, those of us in the energy industry remain focused on making sure every step of the process – from set-up to drilling to fracturing to producing – is conducted safely and responsibly.

The industry has used hydraulic fracturing on more than 1 million wells over the course of 60 years. And we don’t count on a successful track record alone; we rigorously implement safety and environmental plans at every site and seek continuous improvements.

Unfortunately, the facts on hydraulic fracturing have been overshadowed by inaccurate accounts of natural gas production – the documentary GasLand is just one example (take a look at Energy In Depth’s debunking of the claims made in this film).

So moving forward, what do we need to do to have a rational discussion about natural gas development, including hydraulic fracturing?

Those of us in the industry can help by explaining what we do and how we do it safely – in terms that everyone can understand.

Those in local, state and federal governments can help by creating sound policies based on scientific study and fact, not unfounded claims.

And, the American public can help by looking at all sides of the debate and insisting on a facts-based discussion.

At a major energy speech back in March, President Obama said, “the potential for natural gas is enormous.” Potential can only become production if we separate fact from fiction in the hydraulic fracturing debate.

  • Worth a deeper look...