Hydraulic fracturing, or fracking, was first performed experimentally in 1947. Successful commercial operations began in 1949, and since then, fracking has been used for over 2.5 million oil and gas wells around the world. The process originated in the United States and has subsequently grown, with fracking used more than 1 million times in the continental United States.
Hydraulic fracturing has helped realize the potential of vast, untapped American shale gas, delivering more than 600 trillion cubic feet of natural gas to U.S. consumers since the process began. In fact, because of fracking, the United States is now the world’s leading producer and exporter of natural gas and has put the nation on a speed course to energy independence.
Natural Gas Runs Deep
Shale rock layers that reside deep within the earth often contain a sizable amount of untapped natural gas and oil. However, these energy sources are not easy to access. Fracking is the process of drilling down deep into the earth to reach this material. A high-pressure mixture of water, sand, and chemicals is injected into the shale rock, allowing the gas to flow out to the head of the well. This process makes it possible to access natural gas in shale places that were once unreachable with conventional technologies.
The drilling rig, also known as a derrick, is used for the vertical and horizontal drilling operations. After the drilling begins, steel pipe is lowered into the hole, enhancing the integrity of the well. These layers of steel pipe are cemented in place to form a bond between the bedrock and steel casing to eliminate any pathway for hydrocarbons to escape.
During the setup of this well, extra precautions are made to protect underground sources of drinking water. A separate string of steel pipe is lowered into the well to a depth that extends past all potable drinking water. This string of steel pipe, called the surface casing, seals off any potential communication between the drinking water and the hydrocarbons inside the well.
Shale rock formations typically reside more than a mile below the earth’s surface. The well takes a horizontal turn approximately 500 feet above the deep-underground shale formation. The horizontal distance extends 1,000 to 10,000 feet according to the well design and landholding of the drilling company.
Production casing is lowered and cemented into place. The portion adjacent to the vertical section of the well is called the “heel,” and the end of the horizontal section that is farthest from the vertical section is called the “toe.” Perforating and hydraulic fracturing operations begin at the toe and move toward the heel.
Pathways need to be created between the shale formation and the well, and this is accomplished by a perforating gun, which is lowered down into the horizontal portion of the well. Small holes are created that penetrate the steel pipe, cement, and adjacent rock to create a flow path for the hydrocarbons to move into the well. These holes are also entry points for the fracturing fluid to enter the shale formation. A mixture of sand, water, and chemicals is then delivered at high pressure to fracture the shale formation, and the hydrocarbons flow freely through the well and to the surface.
Tools of the Trade
Drilling a hole to obtain natural gas from over a mile deep into the earth requires precision machinery. The nature of fracking operations requires quick turnaround of application information and immediate product delivery. Downtime from drilling will always equate to lost revenue, so it’s important for fracking companies to partner with reliable and efficient parts distributors.
High-quality valves make up an important part of hydraulic fracturing and are typically of the same type used in the conventional oil and gas field industry. Ball, three-way solenoid, and four-way solenoid valves are all used. Plug valves, gate valves, and dart-style check valves are often employed for the stage when pumping equipment is needed. For blending equipment used for fracking fluids, butterfly valves and swing check valves are utilized to connect to the suction side of the pumping equipment.
In addition to these existing valves for oil and gas, some valves are made with special endurance qualities designed specifically for fracking processes. Hydraulic fracturing activities often expose a valve to pulsation and fatigue. This is why it can be advantageous to use a valve with pins that can handle spikes in pressure while still maintaining accuracy. Advanced products such as these can handle pressures from 7,000 to 15,000 psi with easy pin replacement options. With the time constraints and difficult environment involved, using state-of-the-art valve equipment enhances safety, efficiency, and, ultimately, cost effectiveness.
The equipment needed for fracking goes far beyond valves. Rugged bimetal thermometers are also needed to withstand difficult industrial environments. Given the strenuous demands of fracking work, it is helpful that compressed gas and economy pressure gauges have safety features such as safety blowout back steel cases and are UL rated.
The hydraulic fracturing process also calls for convoluted hoses, including pressure-rated hose assemblies that have been lined with Teflon for maximum flexibility. Finally, given that the whole purpose of hydraulic fracturing is to use water to transport hydrocarbons from deep within the earth, it is essential that accurate and sturdy flow sensors are used to ensure that the materials from the shale deposit are being safely transported.
Hydraulic fracturing requires tough industrial equipment. Well-designed, sturdy, and robust components are essential to ensure that operations run quickly, smoothly, and safely.
A Continuously Growing Source of Energy
There can be no denying the impact that hydraulic fracturing has had on domestic energy production. In a time when dependence on foreign oil is seen as increasingly unstable, shale gas exists in abundance. The International Energy Agency estimates that up to 208 trillion cubic meters of shale gas remain recoverable. The National Petroleum Council predicts that fracking will continue, and will eventually account for nearly 70 percent of the natural gas development in North America.
Our ever-present need for energy suggests that hydraulic fracturing and other non-traditional techniques for obtaining hydrocarbons will be a prominent part of the energy landscape in the U.S. and around the globe, both now and far into the future.