Correlation of
Heterolithic Sediments and the role of Differential Compaction. Example from
the Åre Formation in the Heidrun Field, Offshore Mid-Norway
Hammer, Erik1 (1)
Correlation of sandstone units in
heterolithic reservoirs is in many cases difficult, especially in fluvial
sediments where there are large lateral lithological differences. Complexities
may in addition be imposed by diagenetic factors such as differential
compaction. During burial, heterolithic sediments may undergo differential
compaction due to differences in compaction factor for different sediment
types; e.g. clay, sand, coal etc. Poor understanding of the reservoir units may
cause difficulties during pressure supported production because of
uncertainties concerning reservoir connectivity. In this study we examine
possible effects of differential compaction on reservoir correlation within the
Upper Triassic - Lower Jurassic Åre Formation at the Halten Terrace offshore
Mid Norway. The formation consists of lower fluvial plain to lower delta plain
sediments including channels and coal beds, showing large thickness variations
in the reservoir zones. A comparative study of 19 wells has been carried out
for correlation by 1) lithostratigraphic and sequence stratigraphic methods, 2)
investigating diagenesis and compaction, and 3) revised correlation by
considering effects of diagenesis and differential compaction. The aim is to
investigate if effects of differential compaction in a heterogeneous reservoir
are recognizable and/or if they are important factors concerning reservoir
connectivity.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California