Multizone Single Trip Gravel Pack (MZ-STGP) completion has been the mainstay in Mahakam River Delta and North Java Sea in Indonesia since 2007. The system has been used as a sand control solution for its cost efficiency, the ability to complete multiple sands in a single trip and to provide zonal isolation for production selectivity.
Initial completions have used the 9 5/8” system offering large bore and pumping capacity required for deeper zone gravel packing. Additional requirements has driven the need for a use of a smaller system under various scenarios such as cases where 9 5/8” casing cannot reach planned depth, retrofitting gravel pack in existing wells or completing unexpected additional reserves below 9 5/8” casing shoe.
The paper reviews successful history of a 7” MZ-STGP system including its first worldwide installation in 2009. Introduction of the new system has been very smooth including another world's first combined 7” and 9 5/8” multizone gravel pack completion. The paper presents application concerns when considering multizone systems, as well as lessons learnt from the presented cases.
To date, eight wells have been completed successfully using this slimmer system within expected time frame confirming rig time reduction of 8-10 days per well compared to stacked gravel packs. Not only has the 7” MZ-STGP proven to reduce costs for operators, but it has also permited significant flexibility in drilling and completion operations. The system is now considered as a standard contingency for many operators in cases where a 9 5/8” shoe must be set higher than planned or when openhole completion cannot be run inside of an 8 1/2” open hole.