Skip to Main Content

Abstract

In 2011, two discoveries were drilled by PA Resources in the Danish sector. The Broder Tuck 2/2A wells were drilled on a thrusted anticlinal structure, downdip of the apparently small U-1X gas discovery. The wells found an excellent quality gas reservoir within an interpreted Callovian lowstand incised valley containing braided fluvial and marginal-marine sandstones. A top and base seal are provided by mudstones of the over- and underlying transgressive systems tracts respectively. The development of a base seal is key to the presence of a potentially commercial resource downdip of a relatively unpromising old well.

The Lille John 1/1B wells were then drilled on a salt diapir on which 1980s wells had encountered shallow oil shows. Lille John 1 found slightly biodegraded 34° API oil in Miocene sandstones at the uncommonly shallow depth of −910 m true vertical depth subsea (TVDSS). The reservoir is full to spill, whilst the trap developed intermittently through latest Miocene–Late Pleistocene times. It is interpreted that a deeper Chalk accumulation temporarily lost seal integrity owing to glacially induced stress or overpressure triggering top-seal failure or fault reactivation during and after latest Pleistocene diapir inflation. The wider hydrocarbon exploration implications of glaciation on stress, pore pressure and trap integrity appear to be underappreciated.

You do not currently have access to this chapter.

Figures & Tables

Contents

References

Related

Citing Books via

Related Book Content
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal