INVESTIGATION THE NON-PRODUCTIVE TIME AND RELATED DRILLING CHALLENGES IN AZAR OIL FIELD

Non Productive Time (NPT) is the principle reason of drilling project delays. There are various occurrences or situations that lead to stoppage of drilling operations or marginal reduction in advancement of the drilling progress. These occurrences are either observable or unobservable and may be due to the physical characteristics of the well, geology, drilling parameters of the well, operator experience, wellbore quality, equipment downtime, well planning and execution, team communication, management, or project management abilities. Non Productive Time is directly proportional to drilling cost and if it becomes out of control could result in escalation of costs sometimes beyond budgetary allocation. The purpose of this paper is to perform an evaluation on the Non-productive time experienced while drilling wells in Azar oil field. The Azar field is one of the most complicated and challenging for drilling operation in the west Karoun. It has excessive and low pressure layers that are very close to each other. The drilling process can take more than a year, not because of depth but the complex nature of formations. The analysis showed two factors of stuck pipe that leads to fishing operation and low rate of penetration (ROP) had the most influence on creating waiting times. In this study, effective factors hindering the process of drilling operations as well as the related NPT are investigated. Finally, some solutions are presented.

Keywords:

NPT , drilling cost , challenging drilling operation , stuck pipe , fishing , low ROP