AAPG Bulletin, V. 82 (1998), No. 7 (July 1998), P. 1416-1436.

Application of High-Resolution Sequence Stratigraphy to Northwest Hutton Field, Northern North Sea: Implications for Management of a Mature Brent Group Field¹

Stephen Flint,² Simon Knight,³ and Andrew Tilbrook⁴

©Copyright 1998.  The American Association of Petroleum Geologists.  All Rights Reserved

¹Manuscript received November 18, 1996; revised manuscript received July 22, 1997; final acceptance February 25, 1998.
²Stratigraphy Research Group, University of Liverpool, Liverpool L69 3BX, United Kingdom.
³Stratigraphy Research Group, University of Liverpool, Liverpool L69 3BX, United Kingdom. Present address: Saga Petroleum ASA, Kjorboveien 16, P.O. Box 490, 1301 Sandvika, Norway.
⁴Amerada Hess Ltd., 33 Grosvenor Place, London SW1X 7NY, United Kingdom.

We would like to acknowledge the past and present Northwest Hutton partners, Amoco (U.K.) Exploration Company Ltd., Amerada Hess Ltd., Mobil North Sea Ltd., Petrobras (UK), and Cieco for permission to publish this paper. Amerada Hess and Cieco are thanked for their financial and logistical support of the study. The views expressed herein are ours. John Howell is thanked for his help with the ichnology and Brent Cheshire for supporting the project from inception to completion. During manuscript review, discussions with NWH team members Richard Benmore and Toby Read clarified several points on the Etive. AAPG reviewers G. Bertram, C. B. Boutte, A. D. Miall, and former Elected Editor Kevin Biddle, are thanked for improving the paper through their comments. 

ABSTRACT

The Middle Jurassic Brent Group reservoirs in Northwest Hutton comprise shallow-marine, marginal-marine, and coastal-plain reservoir sandstones of both channelized and sheet geometries. The connectivity and production characteristics of these sandstones can be predicted through the application of high-resolution sequence stratigraphic correlation techniques. The Broom Formation overlies a basal Brent sequence boundary and is a lowstand to transgressive systems tract tidal-estuarine complex. The overlying Rannoch Formation comprises shoreface sands that represent a highstand systems tract. The overlying Etive Formation is a multilayer fluvial to estuarine channelized system of near fieldwide development interpreted as incised valley fills. The superjacent Ness Formation is genetically related to the Etive and is the main oil-bearing interval over much of the field. The Lower Ness comprises mouth-bar parasequences and is interpreted to be a transgressive systems tract to the Etive lowstand. The Upper Ness is a nonmarine delta plain succession, interpreted as a highstand systems tract. Upper Ness channel sands typically correlate between several wells and are oriented west-east. An interval of widespread, stacked channels indicates a change in drainage orientation and is related to a high-frequency relative sea level fall. The uppermost reservoir unit is the Tarbert Formation, related to a further major sequence boundary. Original repeat formation tester data support a stratigraphically well- connected reservoir model. Compartmentalization exists and is due to stratigraphic layering (laterally persistent mudstones creating low vertical permeability) and variable dimensions of channels and valley fills.