Giant waterflood project nears completion offshore Abu Dhabi

The Umm Shaif reservoir is mainly in the Arab geologic zone. The rock is limestone or dolomitic limestone with partial barriers formed by anhydrite. The oil column is 550-ft thick and is overlain by a large gas cap. Some 35 wells were drilled in the field and, just prior to the start of water injection, there were 26 tubing strings producing, including single and dual strings. The need for water injection is 2-fold. First, although the 2 fields were jointly producing around 500,000 bpd, pressure has been declining over several years, some wells moving over almost completely to gas. These were having to be shut down. The gas produced with the oil previously was flared. However, it is now fed to a massive LNG plant on Das Island from which the production is shipped to Japan. Water injection was consequently the best way to keep reservoir pressure up. Now oil will continue to flow in quantity, while gas can be made available for sale. The completed Umm Shaif complex includes a power barge, control and accommodation platform, water injection barge, and collector/separator platform. In addition, there is a riser support structure, a platform connected with the Das Island LNG project,more » and one wellhead tower.« less