During drilling of an 8-1/2in hole at 8,000 ft, a complete loss of circulation was observed. drilling was stopped and the mud level in the annulus was observed to fall rapidly. the well was filled with water of 62 pcf density until the annular level remained stationary. if the volume of water used was 65.7 bbl and the mud density is 75 pcf, determine the formation pressure and the new mud weight required to balance the formation pressure. assume the intermediate casing used is 9-5/8 in, 40 # set at 6000 ft. and the drill pipe has grade e with 5in od.