Print this pageHydrocarbon 
Migration
in Mackenzie Delta Sediments
Lloyd R. Snowdon
Macroscopic-scale hydrocarbon migration in Tertiary rocks of the
Beaufort-Mackenzie basin has been investigated using three analytical
approaches: (1) spatial constraints imposed by the physical distribution of oil
source rock pairs defined by detailed chemical correlation, (2) determination of
vertical migration by comparison of the level of thermal maturation of a crude
oil with that of the host reservoir rocks, and (3) observation of the relative
concentration of biomarker compounds that may be sensitive to the extent of
migration. In the offshore of the Mackenzie delta, vertical migration is not
evident, but no available data indicate the extent or importance of lateral
migration. The stratigraphic and structural position of the source rock relative
to the reservoirs ndicate that faults played a major and necessary role in the
migration process. The level of thermal maturity of most Tertiary oils in this
basin is too low to permit the application of the published direct-migration
indicator.
Chemical properties of the oils indicate that two or more episodes of
generation and migration have occurred and that extensive invasion by meteoric
water has occurred at various times in this basin. The observed offshore
decrease in the gas to oil ratio has not been explained but may be related to
migration
.
AAPG Search and Discovery Article #91043©1986 AAPG Annual Convention, Atlanta, Georgia, June 15-18, 1986.