A rare super-giant field
Rumaila is one of the world’s greatest so-called super-giant oilfields – those that contain over a billion barrels of recoverable oil. It is estimated that some 17 billion barrels of recoverable oil are still contained within Rumaila’s reservoirs.
Location and surface area
The field is located 50km to the west of the city of Basra, southern Iraq. The Basra region is home to all six of Iraq’s ports, including the deep-water facility at Umm Qasr.
Rumaila encompasses an area of 1,600 square kilometres, extending approximately 80km north to south and 20km west to east, with the main anticline consisting of two domes, South Rumaila and North Rumaila.
The stacked sandstone and carbonate reservoirs at Rumaila are of Cretaceous age and lie at depths of up to four kilometres. Rumaila’s reservoir are now mature. The Main Pay reservoir has produced oil for over 50 years; but in the north of the field, its pressure levels is falling and requires water injection and other enhanced oil recovery activity to produce effectively; while in the south, the field is producing oil with much higher water content, due to the activity of the natural aquifer that lies beneath.
The Mishrif reservoir, located in north Rumaila, also suffers from low pressure and many of its wells were shut in and ceased to produce many years ago.
Addressing these geological challenges are key to maintaining Rumaila’s current and long term production rate.
Rumaila has been producing for 60 years. It still has plenty of oil left, but as a mature oilfield, it is much harder to produce than it has been in the past.