Equinor and partner Neptune have struck oil in the Sigrun East prospect in the central part of the North Sea. Recoverable resources are estimated at between 7 and 17 million barrels of oil equivalent.
Exploration wells 15/3-12S and 15/3-12AT2 in production license PL025/187 were drilled some 11 kilometers south-east of the Gudrun field on the Norwegian continental shelf.
The Sigrun East wells -- the 10th and 11th exploration wells in production license 025 -- are follow-up wells to the Sigrun appraisal well (15/3-11) drilled in 2018. The aim was to prove extra resources and clarify the commercial basis.
The wells were drilled as sole risk wells by Equinor Energy AS (75%) and Neptune Energy Norge AS (25%). The partners in PL025/187 are Equinor Energy AS (36%, operator), Neptune Energy Norge AS (25%), OMV Norge AS (24%), and Repsol Norge AS (15%).
The primary and secondary exploration targets for wildcat well 15/3-12 S were to prove petroleum in Middle and Upper Jurassic reservoir rocks (the Hugin and Draupne Formations), respectively.
The well encountered three separate oil-filled reservoir zones of 9, 4 and 9 meters in the Hugin Formation, which are about 100 meters thick. The reservoir zones mainly have moderate reservoir quality. The oil/water contacts were not encountered.
The exploration target for wildcat well 15/3-12 A was to prove petroleum in Upper and Middle Jurassic reservoir rocks (the Draupne and Hugin Formations), respectively. The well encountered the Draupne and Hugin Formations with respective thicknesses of about 85 and 120 metres. Both formations are water-bearing. There are indications of oil in a thin, three-meter sandstone layer in the Sleipner Formation in the Middle Jurassic.
Preliminary estimates place the size of the oil discovery between 1.0 and 2.7 million standard cubic meters (Sm3) of recoverable oil. Development of the discovery as a tie-in to the Gudrun field will be considered.
Wells 15/3-12 S and 15/3-12 A were drilled by the West Phoenix drilling rig to a vertical depth (TD) of 3,810 meters and 4,038 meters respectively in 109 meters of water. The wells have been permanently plugged and abandoned.
No formation tests were performed, but extensive volumes of data have been collected and samples have been taken.
Based on the positive exploration results efforts aimed at developing and producing the oil via the Gudrun field will be initiated, which could provide significant added value.
“Sigrun East is a win-win. Exploring near existing infrastructure we prove resources that can be profitably realized, while producing with low CO2 emissions,” said Equinor’s senior vice president for exploration in Norway and the UK, Nick Ashton.
The average CO2 emissions per produced unit on the Norwegian continental shelf is around half compared to the international average. Equinor’s goal is to reduce total greenhouse gas emissions from operated fields and onshore facilities in Norway by 40% by 2030.
“We have said that we aim to be an industry leader on carbon-efficient production. Sigrun East contributes towards this end. Calculations so far indicate that we will manage to produce the oil with carbon emissions below 8 kg/barrel,” Ashton said.
Neptune Energy’s Director of Exploration & Development in Norway, Steinar Meland, said, “We are very pleased to be part of the Sigrun East discovery together with operator Equinor. This is our second exploration discovery together on the Norwegian Continental Shelf (NCS) within a few months, following the Echino South announcement in November last year. This latest discovery will add valuable resources to the Sigrun development, which is located in one of our core areas on the NCS. The Sigrun East wells demonstrate how important exploration is to our company’s growth strategy in Norway. Within a short time, Neptune will have two drilling rigs on contract as operator of six explorations wells to be drilled on the NCS within the next two years.”
West Phoenix will now move to drill wildcat well 6507/8-10 S in production license 889 in the Norwegian Sea, where Neptune Energy Norge AS is the operator.