Therefore, loss of circulation may be a problem in this wellbore if mud weights exceed about 13.5 ppg. This procedure is sufficiently accurate for quick field calculations, but it slightly overestimates the formation fracture pressures because the effective compressibility of the drilling fluid and frictional pressure losses are not accounted for. | Therefore, loss of circulation may be a problem in this wellbore if mud weights exceed about 13.5 ppg. This procedure is sufficiently accurate for quick field calculations, but it slightly overestimates the formation fracture pressures because the effective compressibility of the drilling fluid and frictional pressure losses are not accounted for. |