09/02/2015 Statoil Petroleum AS, operator of production licence 035, is in the process of completing the drilling of wildcat well 30/11-10 A.
The 30/11-8 S discovery was proven in the summer of 2011 in Middle Jurassic reservoir rocks about 25 kilometres southwest of the field facility on the Oseberg Sør field in the northern part of the North Sea.
After drilling the discovery well 30/11-8 S, the operator's resource estimate was between 2 and 9 million standard cubic metres (Sm³) of recoverable oil equivalents. Appraisal well 30/11-10 A was drilled into the reservoir north of discovery well 30/11-8 S.
The purpose of the well was to delineate the 30/11-8 S discovery, increase proven in place oil resources and reduce the range of uncertainty in recoverable resources in Middle Jurassic reservoir rocks (the Tarbert formation). In addition, the licensees wanted to acquire more precise information about the depth of the structure, reservoir and fluid properties, as well as verify communication over the structure.
The well encountered a total oil column of about 260 metres in the Tarbert formation, divided between the upper and middle Tarbert formation with columns of 110 and 150 metres, respectively. The reservoir rocks in the upper and middle Tarbert formation consist of 30 and 55 metres of sandstone of good reservoir quality.
The preliminary size of the discovery is calculated at between 8 and 13 million standard cubic metres (Sm3) of recoverable oil equivalents. The well was not formation-tested, but extensive data acquisition and sampling have been carried out. The preliminary gas/oil ratio is 80-95 Sm3/Sm3. The licensees will consider developing the discovery along with other discoveries in the area.
Well 30/11-10 A was drilled within production licence 035 on cost-sharing with production licence 272, which has the same licensees and ownership interests as licence 035.
The well is the ninth exploration well in production licence 035, which was awarded in the 2nd licensing round in 1969.
30/11-10 A was drilled to a vertical depth of 3673 metres below the sea surface, and was terminated in the Ness formation in the Middle Jurassic. Water depth at the site is 105 metres. The well will be permanently plugged and abandoned.
Well 30/11-10 A was drilled with the Transocean Leader drilling facility, which has thus completed its drilling assignments for Statoil.
Contact in the Norwegian Petroleum Directorate
Eldbjørg Vaage Melberg, tel. +47 51 87 61 00