Opening a new exploration play with the 6302/6-1 Tulipan Discovery
|Location||International Geological Congress,oslo 2008|
|Author||۱StatoilHydro ASA, Norway-۲Aker Exploration, Norway|
|Holding Date||08 September 2008|
The Tulipan (6302/6-1) frontier exploration well was drilled during the summer 2005 in the deepwater area of the western Norwegian Sea. Reservoir sandstone with gas was found at the expected Danian target level, and has thus opened a new exploration play in the Norwegian Sea. The reservoir sandstones are distal deep water turbidites, most likely derived from a westerly source area. The origin of the dry gas is unknown; it could originate from either the Upper Jurassic or a Cretaceous source rock. Structurally conformant AVO anomalies at Tulipan and on other structural culminations within the same gross sedimentary wedge led to high confidence in the fluid fill predictions prior to drilling.
The problem with the Tulipan discovery lies in the definition of its size: The observations from pressure gradients in the reservoir section are contradictory to the seismic amplitude anomaly defining the prospect. The pressure plot derived from MDT measurements in the reservoir interval indicates communication between the gas and the water zone. The implication of this is that the gas zone only extends over a limited crestal area. However, the structurally conform seismic amplitude anomaly indicates gas filled reservoir further down flank and covering a larger area than the pressure gradients suggest. These conflicting observations give rise to several models for interpreting the well result. The amplitude region below the inferred contact is not considered as proven and thus has a risk of failure. Whether or not this area indeed contains gas is of no economic significance. Both the Tulipan discovery and its up-side potential are considered sub-commercial.