The Chestnut Field, Block 22/2a, UK North Sea

Abstract

The Chestnut oilfield was discovered in 1986 and lies within Block 22/2a, Licence P354, of the UK Central North Sea. The field is approximately 7 km south of the Britannia gas condensate field and 8 km SE of the Alba oilfield on the southern edge of the Witch Ground Graben. The field comprises injected Lower Eocene Nauchlan sandstone encased within Horda Formation shales. The Chestnut Field began production in 2008 through the Hummingbird floating production vessel by means of two producer wells and one injector well. The complex reservoir geometries present seismic imaging challenges, and production data have indicated a larger connected volume than mapped from seismic data. In 2017, an infill producer well was drilled to arrest production decline. This well proved the presence and connectivity of sandstone beyond the field interior and increased confidence in using seismic data for predicting the injectite reservoir distribution.

UK oil and gas fields: an overview

“…Remobilized sandstone reservoirs are described by several authors in this Memoir, with Chestnut, Catcher, Varadero and Burgman fields being examples in the Central Graben. Chestnut Field is described by van Oorschot et al (2020b). At Chestnut, the extent of the injected Eocene sandstone reservoir was not fully recognized at first production in 2008.…”