Pingvin – proving a new play in a frontier area
L.O. Løseth, N.E. Haabesland, B. Lindberg, J.O. Hansen and L.B. Henriksen (Statoil ASA)
A wildcat exploration well was drilled in 2014 to test the Pingvin prospect in the Bjørnøya Basin. The main
purpose was to test the oil potential in a stratigraphic trap with positive geophysical indicators for
hydrocarbons. The pre-drill assessment was mainly based on an observed flat spot associated with a
clear amplitude anomaly in the seismic data, and analysis of CSEM data that indicated a strong resistivity
anomaly in the upper part of the structure (see figures below).
Several pre-well models could explain the geophysical observations. One interpretation was that the
prospect could contain gas over oil. High saturation in the gas zone and oil saturation below CSEM
detection limit could explain the observed resistivity anomaly. Another likely explanation was that the
structure only contained gas above water, and that the gas saturation decreased towards the gas-water
contact. A third scenario was a pure oil case where the flatspot could represent an oil-water contact, but
this was considered less likely. The migration and trap mechanisms required to explain hydrocarbons in
Pingvin were quite complex, and pre-drill scenarios also included models without reservoir and
hydrocarbons. For all scenarios, the main objective was to drill the observed flat spot and test the
reservoir properties. This meant to position the well to test the flatspot and the fluid phases above and
below the expected contact.
The well results showed a good sandstone reservoir with good porosity, but poor permeability.
Preliminary analysis indicates that the reservoir is the Torsk formation of Paleocene age (Danian and
Selandian). Well data indicated a gas gradient above the contact and a water gradient below, and
sampling confirmed both phases; thermogenic gas and very fresh water, respectively. The flatspot thus
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represents a gas-water contact. Preliminary resource assessment is in the range between 5 to 20 GSm
of recoverable gas. The rather large range includes a large uncertainty in hydrocarbon saturation,
recovery factor and gross-rock volume. In the upcoming data analysis and discovery evaluation, the
highest priority will be to assess if there has been oil in the Pingvin structure or if there is oil deeper down
in the stratigraphy.
Amplitude anomaly in 3D seismic data.
Vertical resistivity based on CSEM data inversion.
Acknowledgement: We thank Statoil and licence partners RN Nordic, Edison and North Energy for permission to
publish, and WesternGeco and EMGS for permission to publish multi-client seismic and CSEM data, respectively.