16/2-U-18

General

Well 16/2-U-18 was drilled on the Johan Sverdrup Field on the Utsira High in the North Sea. The well objective was to reduce the geological uncertainty in the Espevær North structure in order to place the planned injectors from the E-template in a robust location with regards to sand thickness and FWL.

Operations and results

well 16/2-U-18 was spudded with the semi-submersible installation Deepsea Atlantic on 5 November 2016 and drilled to TD at 2143 m (2139 m TVD) m in the Triassic Skagerrak Formation. Operations proceeded without significant problems. The well was drilled with Seawater and hi-vis pills down to 951 m, with Aquadrill mud from 951 to 1748 m, and with Carbosea oil-based mud from 1748 m to TD.

The Draupne Formation was encountered at 1947 m (1943 m TVD) and constitutes of muddy spiculites. Intra-Draupne Formation sandstone was penetrated from 1954 m (1950 m TVD) to 1978 m (1974 m TVD). A thin Hugin Formation sandstone is between the Viking Group and the Statfjord Group and is in communication with the Viking Group. Shales in the top of the Eiriksson Formation constitutes a pressure barrier. Hence, the pressure gradient in the water in the Intra-Draupne and Hugin sandstones is 0.4 bar higher than in the homogeneous thick sand of the Eiriksson Formation below the shale. These sands have better reservoir properties than