The technical challenges to exploration and development of the Kopervik fairway, Outer Moray Firth, UK

Abstract

Despite a number of targeted and serendipitous discoveries above deeper Jurassic targets in the 1970s and 1980s, the high-quality Albo-Aptian sand fairway of the Outer Moray Firth, informally known as the Kopervik fairway, still remained relatively unexplored until the late 1990s. Following the Hannay and Goldeneye discoveries in 1996, the renewed impetus in exploration drilling on the trend generated a series of commercial oil and gas discoveries. This most recent exploration phase proceeded with a high ratio of well success to failure, despite the significant technical challenges specific to the Kopervik reservoir sands. For the most part, the explorationist has to contend with a play fairway consisting of subtle trapping mechanisms. The recognition of these traps is hampered by the acoustically transparent nature of the sand, ambiguous seismic imaging and depth conversion issues. The subsequent development of this high permeability reservoir remains equally challenging. Many discoveries have low hydrocarbon column heights with an active aquifer and/or mixed phased fluids, which lead to well deliverability and fluid processing issues. In spite of the technical complications, these discoveries are now being swiftly developed by various operators along the trend. In this paper, we discuss how interest in the fairway was renewed only recently, review how the technical concept was developed in an attempt to reduce exploration risk, and how, following a number of early and surprising discoveries, the fairway was rapidly and effectively appraised. Finally, as an example, we review how the application of joint development concepts will lead to the commercialization of the fallow Cromarty Field and the neighbouring Atlantic discoveries.