5Snubbing H R. Units: a viable alternative to conventional drilling rig and coiled tubing technology. SPE 30408-MS,1995.
6Sehmigel K, MaePherson L. Snubbing provides options for broader application of underbalanced drilling lessons. SPE 81069-MS ,2003.
7Herbal S, Grant R. Downhole deployment valve addresses problems associated with tripping drill pipe during underbalaneed drilling op-erations. SPE 77240-MS,2002.
8Vieira P, Larroque F, A1-Saleh A M. The successful application of underbalanced drilling technology for reservoir evaluation and drill- ing performance improvement in kuwait. SPE 10. 4043/18514-MS, 2007.