Print this pageAn Integrated Study of Reservoir Compartmentalization at Ewing Bank 873
EDMAN, J. D., and M. K. BURK
Ewing Bank 873 is a deep-water (775 ft) Gulf of Mexico field discovered in 1991. The reservoir in this combination structural-stratigraphic trap is a series of six stacked and overlapping deep-water turbidite sands that well log, pressure, seismic and geochemical data indicate is compartmentalized. According to these data, especially the differences in oils delineated by geochemical analysis, the three reservoir compartments and their attributes are: 1) A small compartment containing only the A-07 well. This compartment is in the oldest and stratigraphically lowest reservoir lobe and had the lowest initial pressures among the three compartments. Oil in this compartment is notably biodegraded and tends to have among the lower gravity and higher sulfur values measured in the field. 2) A "west" compartment that contains wells on the west side of the field and includes three stratigraphically intermediate reservoir lobes. Pressures in the "west" compartment are intermediate between those measured in the A-07 and third ("east") compartment, and oil quality is relatively uniform and homogeneous. 3) An "east" compartment that contains wells on the east side of the field whose reservoir sands are located in the two stratigraphically higher turbidite lobes. Pressures in the "east" compartment are the highest measured in the field, and in contrast to,the relatively homogeneous "west" oils, the "east" oils exhibit more variable oil quality that can be correlated to increasing biodegradation downdip. Recognition of these three compartments aided significantly in understanding and producing the field.