A well is being drilled at 12,000 ft using an 11-lbm/gal mud when a permeable formation hav- ing a fluid pressure of 7,000 psig is cut by the bit. a. If fluid circulation is stopped, what hydrostatic pressure will be exerted by the mud against the permeable formation? Answer: 6,864 psig. J. Will the welIl flow if the blowout preventers are left open? Answer: yes. c. Calculate the surface drillpipe pressure if the blowout preventers are closed. Answer: 136 psig. d. If formation brine of specific gravity 1.1 enters the annulus up to a depth of 11,000 ft before the blowout preventers are closed, what will be the surface annular pressure after the well is shut in? Answer: 231 psig.