Rassoul Heydari - Islamic Azad University Branch of Omidieh
Hossein afshari pour
Hossein Jalalifar - Department of Petroleum Engineering; Shahid Bahonar University of Kerman
Hossein Moghadasi - Department of Petroleum Engineering; Petroleum University of Technology of Ahwaz

Well drilling is a way to rich the oil reservoirs and oil production. Usually the wellbores have different slope and azimuth and also drill through differentstratums. Thus drilling operation is a risky process. And also wellbore instability cause losing large sums of money and operation stopping. So analysing andpredicting the safe mud weight window is very important for use in future planning. Elastic and strength properties of the formations and magnitudeof principal stresses in the field were estimated from a mechanical earth model (MEM) based on offset well data. The MEM results were calibrated usingresults from laboratory experiments, well tests and drilling incidents from drilling reports. Newly developed software has illustrated that thesafe mud weight window to avoid borehole collapse and fracturing can be obtained from the direct use of drilling and/or the use of sonic data. In this paper,analysing of safe mud weight window in one of Australian oil field was surveyed by using IP (Interactive Petrophysic) software