Why And How
American oil and gas producers today are often faced with energy resources that are hard to reach and even more difficult to bring to the surface. The result? Oil and natural gas production in the United States continues to fall, even as experts continue to revise old resource assessments in favor of the view that Americans are sitting atop more and greater energy reserves than we previously thought possible.
The challenge is simple: How can we successfully locate and produce oil and natural gas for the American people – safely, efficiently, effectively and while still reducing our impact on the environment?
Though it has become unpopular in some quarters to suggest it, hydrocarbons remain today the world’s primary source of energy. Thankfully, with an advanced suite of stimulation and optimization technologies (including hydraulic fracturing), America’s producers are increasingly well-equipped to meet the challenges of tomorrow, today.
Some oil and natural gas wells flow more easily than others. In many cases—up to 90 percent, in fact—it is necessary to stimulate well sites to allow the energy contained thousands of feet below ground to rise to the surface for collection. Hydraulic fracturing is one of the most effective—and safest—methods employed today.
But how is a well actually “fraced,” and why does it play such a key roll in energy production?
The Process
Put simply, hydraulic fracturing is used to stimulate production from new and existing oil and gas wells. By creating or even restoring fractures, the surface area of a formation exposed to the borehole increases and the fracture provides a conductive path that connects the reservoir to the well. These new paths increase the rate that fluids can be produced from the reservoir formations, in some cases by many hundreds of percent.
To ensure that neither the fluid that will eventually be pumped through the well, nor the oil or gas that will eventually be collected, enters the water supply, steel casings are inserted into the well to depths of between 1,000 and 4,000 feet. The space between this first casing string and drilled hole is filled with cement. The casing, cement specifications and cementing process are governed by state and federal regulations as well as industry standards. Once the cement has set, then the drill hole (wellbore) is continued from the bottom of the first cemented steel casing to the next depth. This process is repeated using smaller steel casings each time until the oil and gas bearing reservoir is reached (generally 6,000 to 10,000 ft). The cement and steel prevent any contamination of the water table, and stabilize the well.
With those and other precautions taken, high volumes of fracturing fluids, or “fracing fluids,” are pumped deep into the well at high pressures sufficient to cause the reservoir rock to break or fracture. While different well sites require different mixes of fracing fluids depending on the composition of the rock bed and other factors, almost all mixtures are comprised of more than 95 percent water. As the pressure builds within the well, rock beds begin to crack. More fluid is added while the pressure is increased until the rock beds finally fracture, creating channels for trapped oil and natural gas to flow into the well and up to the surface. The fractures are kept open with proppants made of small granular solids (generally sand) to ensure the continued flow of resources.
Once the rock bed has been fractured, fracing fluids are removed from the well. This removal allows the free flow oil and gas, and is one more step that ensures the environmental integrity of the process. Whatever fluid is not immediately recovered remains trapped in the rock bed, where it cannot come to the surface or enter the water supply.
After the fluids are removed, the well is ready to yield oil or natural gas.
Why Fracture A Well?
Hydraulic fracturing is an environmentally responsible way to make the most of our American energy resources. Without it, wells that would have run dry years ago, or which never would have been productive in the first place, are made viable. Experts believe 60 to 80 percent of all wells drilled in the United States in the next ten years will require fracturing to remain profitable and operating.
We need hydraulic fracturing to ensure a stable flow of American energy and to keep the energy industry generating jobs and economic growth. Without it, thousands of communities across the country supported by oil and natural gas production would lose their prime source of economic activity, and state and local governments would lose critical revenue.
