These days, subsea development solution is getting quite common option for a marginal field development. In PL089 where Idemitsu Oil Development Co., Ltd. has 9.6% share, subsea development system has been applied for Snorre, Tordis, Statfjord East and Vigdis fields. It seems to a person who has no experience about subsea development/completion that "subsea completion" is very special. But there are no major difference between platform completion operations and subsea completion operations except subsea completion requires special tools for installing tubing hanger and subsea tree. Since people can not access directly to the subsea systems, special attention is paid for operation process and procedure as well as company's internal control system.
