16/1-34 A

General

Well 16/1-34 A is located on the Utsira High, north of the Edvard Grieg Field in the North Sea. The primary objective was to appraise the lateral extension and producibility of the Permian Zechstein carbonates found in well 16/1-29 S. The secondary objective was to appraise the Grid Formation injectites and Heimdal Formation sandstones.

Operations and results

Appraisal well 16/1-34 A was kicked of at 555 m in the main well on 1 August 2021. It was drilled with the semi-submersible installation Deepsea Stavanger to TD at 2195 m (2024 m TVD) in the Permian Zechstein Group. The well was drilled vertical down to 543 m, then drilled towards WSW with up to ca 30 deviation at most, then dropping to 20 deviation in the bottom section. Severe mud losses (60 90 m3/hr) were encountered after coring the first core to 2067 in the Zechstein section. The well was drilled with Rheguard Prime oil-based mud from kick-off to 2047 m and with Glydril Plus mud from 2047 m to TD.

The Shetland, Viking and Statfjord groups that are present in 16/1-34 S are missing in 16/1-34 A. In 16/1-34 A this interval, between 2047 m (lower V le) to 2064 (upper Zechstein), contain reworked Shetland Group chalks, possible Cromer Knoll basal conglomerates and reworked Zechstein. The Basement can be divided into a weathered section from 2104 to 2149 m and a non-weathered section below.

Well 16/1-34 A encountered an oil column of about 66 metres, of which 46 metres was in Zechstein dolomite, with good reservoir quality. About 20 metres of the oil column was encountered in basement rock with poor reservoir quality. Pressure measurements acquired using XPT and ORA tools confirmed oil and water fluid gradients were pr