Stuck pipe incidents are one of the most important technical challenges in the oil and gas industry which result in a significant increase in non-productive time during drilling operations and associated costs. This problem typically may occur based on the following major mechanisms: differential sticking forces, inadequate hole cleaning and the consequent formation of cuttings beds in high angle wells, chemically active formations and inadequate mud weight leading to wellbore instability, fractured/faulted formations, and over-pressured formations. Different methods have been proposed and used in the field for stuck pipe prevention and freeing of stuck pipe.
This paper presents the statistical study of about more than one thousand stuck pipe events which occurred from the early year 2004 to the end of 2006 in different fields and formations in Iran. For this purpose, drilling data including drilling mud properties, wellbore geometry, stuck pipe depth, description of stuck freeing operations and associated time, etc. were collected and categorized. The influence of various parameters on stuck pipe were studied and statistically evaluated. Based on the results of this analysis reasons for stuck pipe events and potential ways to mitigate stuck pipe are suggested.