Fracturing equipment includes pumping units, blenders, bulk handling equipment such as sand transports and frac fluid transports, a trailer-mounted manifold, and frac bus. The frac fluid flows out of perforations in the casing or, if the well is riot cased, packers arc used to isolate the formation. The frac fluid is usually water (possibly mixed with acid) or diesel oil. Thickening agents can be used to increase frac-fluid viscosity.
Propping agents (small spheres) such as weil-sorted sand or aluminum-oxide pellets, are suspended the fluid and are used to hold the fractures open after the pumping stops, The proppant or sand concentration is usually 2-4 lbs/gal and is mixed with the frac fluid in the blender The frac job is measured by the pounds of sand used which usually varies from 20,000 to 1,000,000 lbs in a massive hydraulic frac.
Higher injection rates form Longer fractures. Some types of hydraulic fracturing include a)Hydrafrac, b) sandfrac, c) waterfrac, d) acidfrac, e) superfrac, 1) gelled nraterfrae, g) gelled oilfrac, h) emulsion frac, and i) vapor frac. Hydraulic fracturing was developed in 1948 and was originally done through a tubing string to below a packer.