Chapter 1. Introduction

Abstract

Sequence stratigraphy has become a powerful tool in the basin analysis of the North Sea Basin, and will continue to be important in the maximisation of the remaining hydrocarbon resources of Jurassic reservoirs in the region, whilst also moving through the energy transition. The chapter provides background to the main theme of the memoir, which is the description of a revised sequence stratigraphy scheme for the Jurassic to lowermost Cretaceous of the region, recognising 39 stratigraphic sequences (“J sequences”). The sequences are illustrated by 85 reference wells (56 UK wells, 22 Norway wells and 7 Denmark wells), showing chronostratigraphy, lithostratigraphy, wireline logs, key biostratigraphic markers. The reference wells illustrate sequence development, together with their lowe and upper boundaries. Comparisons of the North Sea Jurassic sequences with onshore outcrop sections, from the United Kingdom, demonstrate that many of the sequences can be recognised onshore. A comparison of the well sequences with seismic sequences is made in 17 illustrated seismic lines, demonstrating the seismic expression of many of the defined sequences.