PES utilizes the most state-of-the-art hydraulic fracturing equipment currently available to the market place. We are currently operating three complete high-specification hydraulic fracturing fleets with a fourth set to come online in Q4 2013. Our first two hydraulic fracturing fleets consist of twenty 2,500 brake horsepower ("BHP") "Quintuplex" hydraulic pumping units, yielding 2,250 hydraulic horsepower ("HHP"), ten 2,500 BHP "Destiny Triplex" hydraulic pumping units, yielding 2,250 HHP and twenty 2,250 BHP "Triplex" hydraulic pumping units, yielding 2,000 HHP, representing a total of 107,500 HHP. Our third fleet consists of twenty-one 2,250 BHP hydraulic pumping units, yielding 2,000 HHP that will increase our total HHP to 149,500 HHP across the three fleets. Our state-of-the-art hydraulic fracturing units are rated 15,000 pounds per square inch ("psi") or higher and are specially designed for the most complex and challenging hydraulic fracturing projects, which typically involve long lateral segments and multiple fracturing stages in high pressure formations. We believe our units are among the highest-specification units available in the market today.
Hydraulic fracturing services are utilized when the formations holding oil and natural gas lack the permeability to release their hydrocarbons as is typical in many unconventional oil and natural gas plays. Fracturing involves pumping a specially formulated and proprietary slurry down a well casing or tubing, under high pressure, causing the underground formation to crack or fracture. Suspended in the slurry is a propping agent ("proppant"), generally consisting of sand, resin-coated sand or ceramic particles, which keeps the fracture open and allows the oil or natural gas to flow more freely to the surface. The proppant fills the fractures created by the mechanical fracturing process and preserves the permeability enhancement of the formation. The extremely high pressures required to stimulate wells in the regions in which we are contracted to operate presents a challenging environment for achieving a successfully fractured horizontal well. As a result, an important component of our value proposition to customers is our technical expertise and experience that allows us to work directly with the customer's engineers at the job site to provide advice and assistance to improve well completions. Our engineering staff also provides technical evaluation, job design and fluid recommendations for our customers as an integral element of our fracturing service.