Ali Shakouri - M.Sc. in Petroleum Engineering, Sharif University of Technology
Mohsen Gholampour - M.Sc. in Petroleum Engineering, Amirkabir University of Technology

Encountered in several common types of operations in the oil industry are problems associated with the prediction of formation fracture pressure gradients. When wells are being drilled in both new and old fields, lost circulation is often a very troublesome and expensive problem. Complete loss of circulation has been disastrous in some cases. Many times, such disasters could have been avoided if techniques for calculating fracture pressure gradient had been employed in the well plans, and if casing strings had been set, and mud weight plans had been followed accordingly. The objective of this work is to make a critical examination of the methods used to estimate fracture pressure gradient and determination of fracture gradient from drilling parameters

Fracture Pressure, Pore Pressure, Poisson’s Ratio