Abstract: Unconformity Detection and Characterization Using 3-D, 3-C Seismic Data, Joffre Field, Alberta Canada
GRAU, ANNE and LUCA DURANTI, Colorado School of Mines, Golden, CO
Summary
Joffre Field is located in south-central Alberta, Canada,
between Calgary and Edmonton, and produces oil from Devonian
carbonates in the Western Canada Sedimentary Basin. A 3-D,
three-component (3-C) seismic survey was originally acquired over
the Joffre Field area as a part of a study characterizing reservoir
properties of Devonian Nisku and Leduc reefs. For this study,
however, the seismic volumes were utilized in an attempt to
identify and characterize the top of the regional Paleozoic
unconformity that has long limited exploration efforts in this
stratigraphic interval. The unconformity at the top of the
Paleozoic was found to be well imaged in the compressional (P)-wave
data. Additionally, amplitude anomalies and velocity ratios
(Vp/Vs) support the presence of the
unconformity as defined on the P-
wave
volume.
The detection of the unconformity on seismic has great
implications for defining elusive oil and gas targets that
potentially exist in association with the unconformity. Seismic
interpretation allows for detailed understanding of geologic
systems and their distributions above and below the unconformity
surface. Considerable evidence for stratigraphic and structural
settings suitable for potential
hydrocarbon entrapment were also
interpreted form the seismic in close association with the
unconformity. These
potential
reservoirs include Manville valley
fill sequences above the unconformity surface, and Mississipian
carbonate erosional remnants and shoaling environments below the
unconformity.
AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah