Abstract: Structural Controls on Trap
Generation and
Integrity
JONES, G., R.J. KNIPE and D. HENSON (Rock Deformation Research, Leeds University, Leeds LS2 9JT U.K.)
Summary
Tectonic structure is commonly a key factor in the assessment of
trap
development and
trap
integrity prior to drilling in
structurally complex basins such as the U.K. North Sea. Well and
core data show that sealed faults are generated by a number of
processes in the basin, whereas
fault
breaching and leaking is
evidenced by the known occurrence of dry or underfilled structures
at Mesozoic levels (often with residual hydrocarbons indicating
previous charging episodes) and by the widespread occurrence of
Jurassic sourced oils in Tertiary reservoirs. Although these
processes have for some time been invoked to explain certain
geological observations in the North Sea, the advent of 3D seismic
datasets (including coherency cube data), together with seismic
attribute mapping and the widespread utilisation of image
processing techniques (e.g. false coloured shaded relief mapping)
now mean that both the location and geometry of
fault
zones can be
far more readily defined. Such high quality seismic data, along
with an increased understanding of
fault
zones and faulting
processes, is demonstrated to have exerted a major impact on our
understanding of the distribution, size and internal
compartmentalisation of hydrocarbon accumulations. Using a number
of selected examples, we show how such processes have controlled
the distribution of hydrocarbons and how they impact on field
development strategies. Finally, the wider implications of these
processes in hydrocarbon exploration and production are
considered.
AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah