Indonesia ‘’Tunu 18 days’’ Project Case History: Innovations and New Technologies Bringing the Well Construction Performance to Unthinkable Levels

摘要

Tunu is a giant gas field discovered in 1977 and located in the Indonesian Mahakam delta, East Kalimantan. To support the field development maintaining a high gas production level, more than 750 wells have been drilled and completed. Late 2010, Tunu field cumulative production was over 7.5 Tcf gas. Five rigs are continuously drilling in the swamp area to deliver around 100 wells per year highlighting the stakes associated to the well construction optimization. Since the 80’s and the early beginning of the drilling operations on Tunu, a tremendous work has been done to 1) reduce the overall well construction duration, 2) reduce the well equipment costs without jeopardizing the operations safety and the wells productivity. The first important leverage was the implementation of innovative well architectures in order to construct ‘’fit for purpose’’ wells strictly answering to the subsurface formation characteristics avoiding any over design. The evolution of the technology has been fully utilized and wisely implemented in order to improve the performance of our drilling and completion operations. A huge effort has been delivered to minimize the costs associated to the equipment design and material selection. Finally, a shared performance culture has been successfully implemented on our operations to systematically challenge ourselves outside of our comfort zone: the ‘’Industrialization’’ of the well construction process is now developed. The Tunu wells targeting the ‘’main zone’’ reservoirs have seen their average duration reduced by 70%!!! From a well duration of 55 days in the early 80’s, the drilling and completion teams managed to reduce it down to 17 days in 2011. This performance level has been reached over 30 years of thorough improvement process follow-up. A joint effort of all involved entities as geosciences, marine, logistics, planning, service companies and well teams made this achievement possible. In 2011, two innovative well architectures have been implemented on Tunu and field trials are planned for two new technologies. The continuous improvement process is not closed yet: ‘’Tunu 15 days’’ on its way to become a reality?