A water injector located in an offshore Sabah field, Malaysia was sidetracked and completed as a single string completion on 13 September 2006. This water injector was designed for 10,000 barrels per day of seawater injection. It was completed as open hole with swellable packers targeting H sand only. However, due to differential sticking while running completions, the completion string became stuck at 700 feet above the intended setting depth. Since then, the well had been closed to avoid the risk of nearby fault activation.
Due to the initial injection behavior of the new injector and the fear of fault reactivation, it was decided to re-complete an injection well by isolating the area near the fault it was intersecting. This was achieved by setting bridge plugs to isolate existing zones and re-perforate a new zone above the plugs. The original consideration to recomplete the well in 2008 was to use a conventional coiled tubing unit to access the horizontal section of the water injector. Due to the small size of the platform at this well, there was not sufficient space for placement of coiled tubing surface equipment, a dedicated barge equipped with catenary system had to be considered. Total cost and anticipated risks were high and as such, recompletion of this water injector well by way of a conventional coiled tubing unit had to be classified as low priority due to limited barge time allocated in the 2008 coiled tubing intervention campaign, which naturally became non-feasible and non-viable to execute.
An unconventional method of recompleting the horizontal water injector purely on electric wireline and wireline tractor was then considered and evaluated in 2009, in terms of technical do-ability, economics and risks involved. Recompletion of the water injector was then executed successfully in the same year purely on electric wireline on a shore-offshore-shore daily tripping arrangement at one fourth of the originally anticipated cost when compared to a barge involvement. Successful re- activation of the water injector well realized a significant increase in reservoir ultimate recovery as well as oil gain over the following years of production from the H sand.
This paper will describe the background of the project, recompletion concept selection and well delivery process, actual execution and result of operations. The identified key success factors are also discussed.