6305/9-1

General

The exploration well 6305/9-1 was drilled on the "Blåveis" prospect in the southeastern part of the block, east of the Ormen Lange Field. The main objective of the well was to test if hydrocarbons were present in the Tertiary Egga Member in the Våle Formation, and in the Maastrichtian Springar Formation sandstones.

Operations and results

Wildcat well 6305/9-1 was spudded with the semi-submersible installation Transocean Arctic on 9 July 2001 and drilled to TD at 2655 m in the Late Cretaceous Springar Formation. The well was drilled with seawater and hi-vis pills down to 680 m and with GLYDRIL KCl/polymer mud from 680 m to TD.

In the Lower Paleocene an Egga Member sandstone of the Våle Formation was found, with good sands that became increasingly interbedded with claystone towards top of the underlying Springar Formation. The clean sandstone intervals were high porosity - high permeability reservoirs. No hydrocarbon indications were observed. One core was cut in the Egga Member, covering 17.4 m of the 54 m thick sandstone. The core shows a deposition within stacked channels and related overbank areas of intraslope basin turbidite system. The reservoir properties in the cored interval show 27.5% porosity and 2280 mD permeability. No core was taken in the Springar Formation. The reservoir quality of the Springar Formation clean sands is about similar to the Egga Member but the net sand fraction is less. The geology of the well was very much as prognosed, especially the formation tops in the lower part of the well came in almost as prognosed. The formation pressure in the lower Tertiary was hydrostatic. Organic geochemical analysis showed vitrinite reflectance Ro values in the range of 0.35-0.40 for the Egga reservoir sandstone and Springar Formation, which means that source rocks at this level are thermally immature for hydrocarbon expulsion. Extracts from samples of the Egga Sandstone and Springar Formation gave on