A Growth Model for Clastic Intrusions Adjacent to Sand-Rich Submarine Channels and Its Impact from Hydrocarbon E&P: Kyrre Fm (Upper Cretaceous), Northern North Sea Basin
Christopher A. Jackson1, Gillian P. Barber1, and Mads Huuse2
1Earth Science and Engineering, Imperial College, London, United Kingdom
2Department of Geology & Petroleum Geology, University of Aberdeen, Aberdeen, United Kingdom
The North Sea Basin contains some of the most intensively studied examples of large-scale clastic intrusions associated with producing deep-water sandbodies. To-date, however, most studies have focused on the seismic expression, stratigraphic distribution and general geometry of the intrusions, in addition to the impact of intrusions on the reservoir geometry and production. In this study, 3D seismic data is utilised to propose a novel model for the growth of large-scale clastic dykes. Plots of the size of clastic dykes along the length of the a 15 km long deep-water channel indicate that they attain a maximum height of 110 m above and extend up to 1.8 km laterally away from the channel. The dykes are neither continuous nor of the same size along the length of the channel; pronounced along-strike ‘maxima’ and ‘minima’ in injection size are observed which serve to compartmentalise the channel margin dykes into ‘segments’ which individually are ca. 0.5-1.5 km in length. These variations in dyke size are reminiscent of displacement-length (D-L) plots for large normal and reverse faults which have grown via a process of linkage of individual, initially isolated segments. Based on this geometric similarity, a model for clastic dyke development is proposed whereby individual dykes form at ‘seed points’ and then propagate vertically and laterally. Hydrofractures and the associated clastic dykes then propagate radially away from these seed points to eventually fully or partially coalesce along-strike. This study indicates that 3D seismic data provides a useful method to investigate the geometric evolution of large-scale clastic dykes adjacent to deep-water sandbodies. In addition, the clastic injections mapped in this study indicate strong modification of the original reservoir geometry which may require complex production methods to exploit any contained hydrocarbons.
AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery