Rijn is an oil field located in block P15 in the South of the Dutch North Sea, in which ONE has a 14.19299% non-operated interest. It was discovered by Amoco in April 1982 with the P15-3 well, which tested oil from two reservoirs in the Lower Cretaceous at a combined rate of 2,500 bbls/d. The main reservoir is the Vlieland sandstone which lies at a shallow depth of around 2,000 m. The field was developed using three platforms: a process and accommodation unit and two wellhead platforms. 25 wells were drilled of which approximately a half were used for sea water injection and a half for production. The wells were drilled from two wellhead protector platforms, P15- A and P15-B, processing took place at P15-C. Production from the field started in 1985 peaking at 22,000 bbl/d in this year and declined from there to about 1500 bbl/d in 1998 at which time the field was shut in. The reason to shut the field in was a combination of low production, low oil price, an additional penalty on the oil price due to mercury pollution caused by the condensate carried by the same pipelines and integrity problems with the wells. The recovery from field was then about 18%.
In 2001, the P15-B satellite wellhead platform was abandoned and removed. As the oil recovery of the Rijn field was still low, it was decided to redevelop the field, installing a system to inject the produced water and equipping 5 producing wells with ESP's.
The first phase of the redevelopment of the Rijn field took place from December 2007 onwards, with first production mid November 2010. It involved the complete recompletion and perforation of five original oil production wells including installation of ESP’s, the recompletion of 3 water injection wells and engineering, procurement and construction of new facilities. In 2014, a further infill well was drilled that can be considered to be part of the same redevelopment.