No sand, no oil, no nothing

The Zumba prospect in the Norwegian Sea was drilled in a graben setting targeting hydrocarbon-filled Upper Jurassic Rogn Fm sandstones embedded in Spekk Fm shales. The prospect, evalutation of risk and results will be reviewd in the Recent Discovery conference on May 10-11.

The prospect was highly supported by geophysical observations and quantitative seismic interpretation.


Fluid impedance from AVO inversion showing a hydrocarbon anomaly at the target level. Zumba well (6507/11-11) trajectory superimposed (dashed white line). Figure: Tullow Oil

Reserovoir: Sedimentological studies indicated erosion of sand-rich Fangst group on the structural highs, representing a likely source of sandy deposits in the Zumba graben.
Source: The Spekk Fm was interpreted to be immature at the burial depth of the Zumba graben, but a working petroleum system in the area from the Gimsan basin in the south has resulted in several oil, gas and condensate fields in the structural highs neighboring the Zumba graben.
Trap: The trap was considered high risk – high reward, and the potential upside of the new play model was substantial.
Disappointment: However, the well (6507/11-11) was dry and only a thin Rogn Fm with oil shows was encountered within a massive Spekk Fm interval.