As the well drilling the Dugong prospect (34/4-15, PL 882) in the Norwegian Northern North Sea entered the reservoir, the geologists reported traces of oil. The operator then decided to take a core test. “Upon entering the reservoir, logs and cuttings have identified hydrocarbons and a decision has been made to initiate coring,” the company writes in a press release.
Dugong is operated by Neptune Energy (40%) and partners Concedo (20%), Petrolia NOCO (20%) and Idemitsu Petroleum Norge (20%) and is located in close proximity to the Snorre field.
With the reservoir reported to be at a depth of 3350 – 3400 meters, Expronews wrote a short article recently speculating what the primary target of the well could be. The conclusion was that Upper Jurassic, Middle Jurassic or possibly Triassic sandstones could be candidates.
Partner Concedo published a summary of the Dugong prospect in their 2019 Annual Report, which sheds more light on the main target. According to this report, the primary target of the well is the Rannoch Formation of the Middle Jurassic Brent Group. Based on the cross-section published in the Annual Report, which has been used to create the featured image for this article, the closure seems to be mainly a truncation trap in combination with an element of structural and/or stratigraphical trapping.
The prospect has been worked up using extensive reprocessing and subsequent interpretation of the CGG Tampen 3D survey. In addition, amplitude mapping including angle stack analysis and the evaluation of fluid indicators were carried out.
If the cores and logs confirm the presence of oil, Neptune Energy has an option to drill an appraisal well. It will therefore take a while before the firm is able to confirm the possible size of the discovery. The appraisal well will aim to determine the oil water contact as well as testing the secondary target, the Upper Jurassic intra-Draupne or Munin Formation sandstones as can be seen in the cross-section. The Munin Formation sands produce oil in Statfjord Nord and Tordis further south.
HENK KOMBRINK
