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Explore the use of composite materials in mist drilling techniques, specifically in the context of the Mechanical Engineering Department at Al-Mustansiriya University. Understand the effects of mist drilling on hole cleaning efficiency and the required air injection rates. This study is conducted by Dr. Nazem Majbil Falah.
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الجامعة المستنصرية كلية الهندسة قسم الهندسة الميكانيكية تكنولوجيا حفر مرحلة 4 COMPOSITE MATERIALSد. ناظم مجبل فالح تكنولوجيا حفر 6
Mist Drilling • Liquid volumes are only 1 to 2 percent at the prevailing temperature and pressure.
Hole cleaning, mist • Water droplets act similarly to cuttings with slip velocity of near zero - mists do not clean the wellbore more efficiently than dry gas. Therefore annular velocities are high. • Circulating fluid density is increased however and may add to the frictional pressure losses.
Hole cleaning, mist • The increased density will lower the terminal velocity of the cuttings, but will increase the BHP reducing the volumetric flow rate at the bottom of the hole. • Higher air injection rates are usually required when misting than with dry air.
Application of Angel’s method to mist drilling • Determine the penetration rate that would generate the same mass of cuttings as the mass of liquid entering the well over a time period. This includes any base liquid, foamer, and water influx.
Angel’s method for mist • The minimum air injection rate, required for good hole cleaning during mist drilling, is determined; either from Angel’s charts or from the approximation in equation 2.17