Risk Function Modeling Of Stuck Pipe in South Iran Oil Field: A Case Study

The complexity of wells increased significantly in later years especially in fractured carbonate rock of Asmari formation. As the production take place from this formation in Iranian major oil reserve and pressure depletion occur in these reserve the risk of formation collapse increased in this formation. Overbalanced drilling which use frequently in these reserve increase this risk. The shale layer and their swabbing due to abstracting water from drilling mud is one of the main causes of stuck pipe in this formation. Fractured rock and unconsolidated sub layers which exist in this formation are potential risk for stuck pipe. This paper presents some strategy to minimize the risk of stuck pipe in this formation. The study of the stuck occurred in this formation from 2003 up to 2005 and the data gathered from these stuck and information of freeing or sidetracking operation and also the problem related to stuck pipe and result of data analysis will be present in this paper. Also the best procedures for freeing are suggested and some recommendations are mentioned to reduce the cost and time consumed for freeing procedure and prevention of stuck.

Keywords:

stuck pipe , shale layer , freeing , risk managements