“…Moreover, compared to other kinds of blowouts, the underground blowouts can be the most difficult, dangerous, and destructive situation in well control (Grace, 2003;Barnhill and Adams, 1979). Remedies to UGBs include relief wells (Leraand, et al, 1992 andFlak, et al, 1995), dynamic methods (Gillespie, et al, 1990), injectable pressure-activated sealant technology (Rusch, et al, 2004), and the application of novel lost-circulation material squeeze systems (Sweatman, et al, 1997).…”