Abstract
Harding Central is a high permeability turbidite reservoir in the Central North Sea. It has been produced with water injection for pressure support and gas injection for disposal of evolved gas since 1996. The initial oil in place has been tightly constrained by high quality seismic, high density of well penetration and various dynamic data. The production data show that we have already recovered 70% of the oil initially in place by end of 2008. We expect the reservoir to achieve 74% recovery without further infill drilling by the end of field life.
We attribute this extremely high recovery factor partly to high rock quality with low Sor, and more importantly to the good understanding and effective management of the reservoir. This paper will summarise key methods by which we have achieved such a high recovery factor, namely (1) good well design and placement to ensure high rate and avoid early coning; (2) 4D seismic used to manage fluid contacts and identify unswept area for infill targets; (3) repeated GOC logging to underpin reservoir management strategy; (4) solid reservoir engineering to support business decisions; and (5) stable production.
