Horizontal drilling and hydraulic fracturing are technologie

Horizontal drilling and hydraulic fracturing are technologies that have yielded a natural gas revolution. These technologies are often applied to shale rocks that must be stimulated (fractured) in order for the natural gas to be released. To do this water, chemicals, and sand \"frac fluid\" are pumped into the well. Google it to learn more. This is a very energy intensive process. Suppose a fleet of stimulation pumps is used to compress water at 20 degree C to 7251.9 psi. Suppose a well requires 1,000,000 gallons of \"frac fluid\". What is the minimum amount of energy required to pressurize this water. Would the actually energy required be more or less? Based on a review of literature does this volume of water and required pressure seem reasonable? Please provide a good engineering analysis and any sources used for the analysis.

Solution

Given, P_{^{req =}} 7251.9psi = 500bar, litres of water required v= 1000000gallons

we know that, density of water d=1000kg/m³ and g=9.81

mass of water required =1000000 * 8.345 = 8345000pounds [since one gallon contains 8.345 pounds]

required head h_req= P^_req /(d * g) =5096.84m = 16721.91601 ft

therefore the energy required = mass of water * head required = 8345000 * 16721.91601 =13.95 *E10 lbf

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Actual energy required will be more since in actual practice there are head losses as well as the machines are not 100% efficient.

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yes it seems quite reasonable as we have break the rock not to cut it. Cutting will require more pressure but breaking can be occured at low pressure(as compared to cutting) and high volume.