Application of outcrop analogues in successful exploration of a sand injection complex, Volund Field, Norwegian North Sea

Identification and exploration drilling of the Volund Field as part of a sand injection complex is the first example of deliberate targeting of sandstone intrusions in oil exploration. Outcrop data were an important element in the process of constraining the uncertainty associated with reservoir presence and connectivity. A strong lobby against the relevance of sand injectites as exploration targets, and significant uncertainty associated with sub-surface sand injectite analogues associated with existing oil fields, combined to discourage and down-grade Volund's prospectivity. Few outcrop studies provided data of relevance to exploration of sandstone intrusions and original outcrop data were utilized in evaluation of Volund. Sills and saucer-shaped sandstone intrusions are the most common reservoir units observed at outcrop and similar features were identified in the 3D seismic across the Volund Field prospect. A large-scale sand injection origin rather than a depositional origin was proposed. Outcrops of sandstone intrusions demonstrated excellent reservoir quality in composite sandstone bodies that cross-cut depositional bedding. High-quality reservoirs with excellent vertical and lateral connectivity are observed and used to support the prediction of similar quality reservoirs in the Volund prospect.