Publications

This paper presents lessons learned from 4 recent well interventions performed in the Natuna Sea by Star Energy. The lessons are drawn from 2 wellservicing, 1 workover, and 1 well completion, during operations conducted on subsea wells using a drillship. The main challenges encountered during this campaign were: (i) uncertainties related to weather conditions, (ii) the condition of nearly 10- year old subsea wellhead equipment and wellbores that had not been touched since installation (iii) positioning of the rig around subsea wells and other subsea infrastructures, and (iv) uncertainties associated with contractor capabilities for this unique activity.Generally, the petroleum industry has placed a low priority on production recovery through subsea well interventions compared to the drilling of new wells. The uncertainty and risks are perceived to be too high to justify this investment in well intervention / well reentry. This is especially true for Star Energy, a small national energy company founded in 2003. Moreover, the expertise required for subsea well intervention activities is difficult to source locally. However, considering the robust oil prices in 2005, the Company decided to take advantage of the opportunity to access additional reserves and maximize oil and gas production by initiating this intervention work. Bringing together and promoting the collaboration and real-time flexibility between contractors from different disciplines and locations was one of the key factors for achieving success in this project.