Geologic controls on oil & gas distribution at the Brent and Statfjord fields, North Sea

Abstract

Summary The Brent and Statfjord fields are two giant oil & gas fields in the northern North Sea. Depositional environments and the ages of reservoirs, trap styles, and seals of the two fields are similar; however, oil & gas column heights and oil phase GORs differ significantly. We completed an integrated petroleum system analysis including 1) mapping trap container geometry and fetch/drainage areas; 2) reservoir & fluid PVT models; and 3) trap charge volume history models. Our analysis incorporates published information by operating companies (Shell for the Brent field & Mobil, the then operator for the Statfjord field) and open data at the U.K. North Sea Transition Authority (NSTA) and the Norwegian Petroleum Directorate (NPD) websites. We present a viable interpretation for the geologic controls, including the volume of expelled oil and gas, instantaneous GOR, top seal strength, and a fill-n-spill relationship between the Brent to Statfjord field, on the oil & gas distribution at the Brent and Statfjord fields. Our interpretation adds new insights to the large body of published literature on petroleum system elements and geologic processes of the giant Brent and Statfjord fields.