Jurassic non-marine source rocks and oils of the Porcupine Basin and other North Atlantic margin basins

Abstract

A detailed geochemical study has shown that oils from the Porcupine and Jeanne d'Arc basins were not sourced from a typical, fully marine Upper Jurassic Kimmeridge Clay Formation equivalent. Rather, these oils are thought to be a mixture of hydrocarbons derived from an atypical Upper Jurassic shale and from a Middle Jurassic non-marine source interval. Standard geochemical techniques were used to analyse a suite of oil samples from the Atlantic margin, along with new proprietary geochemical parameters which can discriminate age and depositional environment. The results indicate that oils from the Porcupine and Jeanne d'Arc basins are very similar, and originated from a mixture of an unusual marine source rock and a lacustrine algal source rock. This conclusion is strengthened by considering the regional geology, as several marine and non-marine potential source rock intervals are present in both the Porcupine and Jeanne d'Arc basins.

Hydrocarbon generation modelling in a multiple rifted and volcanic basin: a case study in the Foinaven Sub-basin, Faroe–Shetland Basin, UK Atlantic margin

“…There is no indirect evidence for these source rocks operating in the Foinaven or Flett sub-basins, probably due to their deep burial, and no hydrocarbon potential has been attributed to them in this study. Rich lacustrine-facies oil-prone sources, of Middle Jurassic (AalenianBathonian) age, occur in the Hebrides and Solan Basins, while gas-prone source rocks occur in well 206/5-1 in the Flett Sub-basin (Scotchman et al 1998;Vincent & Tyson 1999;Butterworth et al 1999;Isaksen et al 2000;Scotchman 2001). These are overlain by CallovianOxfordian age Heather Formation equivalent source rocks deposited in a marine environment in wells 204/ 22-1 and 206/5-1, the source quality varying between gas-and oil-prone depending on the depositional environment and the degree of terrestrial kerogen input.…”

The geology of the UK Hatton-Rockall margin

“…Most of the sedimentary basins underlying the margins of the North Atlantic contain discovered or producing oil and gas fields or contain potential hydrocarbon source rocks (Butterworth, Holba, Hertig, Hughes, & Atkinson, 1999;DeSilva, 1999;Roberts et al, 1999;Spencer, Birkeland, Knag, & Fredsted, 1999;Williams et al, 1999). A pre-rift continental refit of the circum North Atlantic region for the Mesozoic, before the opening of the North Atlantic Ocean (e.g.…”

Petroleum geochemistry of the Lower and Middle Jurassic in Atlantic margin basins of Ireland and the UK

“…Middle Jurassic source rocks and generated oils have been recognized in the Porcupine and Jeanne d'Arc basins (Cornford 1998;Butterworth et al 1999), while source rocks occur in basins in the northeast Rockall Basin/West of Shetlands areas (Hitchen & Stoker 1993;Scotchman et al 1998;Holmes et al 1999;Lamers & Carmichael 1999) and in the Hebrides Basin (Vincent & Tyson 1999). This paper will concentrate on the development and distribution of the Lower and Middle Jurassic petroleum systems.…”