HOLMAN, W. E., and MADHU KOHLI, Shell Offshore Inc., New Orleans, LA

ABSTRACT: GC 65 (Bullwinkle) Production Performance Report "J" Sand Package Internal Architecture, Poster Session

Bullwinkle entered a new phase in its life as production began through permanent facilities, yielding production in excess of 58,500 BOPD and 90 MMCF/D from only 20 producing wells. Nine, conventionally completed wells have consistently produced at rates above 4000 BOPD. A strong emphasis has been placed on how to best manage the prolific "J" sand reservoirs, which constitute 90% of the field reserves. Understanding the reservoir architecture of both the greater "J" sand package as well as its individual members provides the foundation to an effective reservoir management scheme.

A new perspective on reservoir heterogeneity and connectivity is becoming possible as production data are incorporated into the subsurface model and compared with seismic/well control. Pressure data are important as well as fluid properties from individual wells. Reservoir simulation continues to shed light on probable aquifer dimensions as well as on individual reservoir behavior. The following observations have been made as a result of completion, production and simulation experience:

(1) Individual members ("J1"-"J4") have excellent lateral continuity.

(2) The "J1" through "J4" reservoirs are in pressure communication. Communication appears to be occurring across erosional surfaces within the oil column ("J1/J2") as well as through a common aquifer ("J1/J2/J3/J4").

(3) The greater "J" sand reservoir is divisible into two major units (i.e., "J1/J2" and "J3/J4" respectively) as the later appears to lag the pressure decline of the "J1/J2" by approximately 200 psi.

(4) Aquifer/pressure support is greater than anticipated, possibly due to "J" sand intercommunication as well as to high reservoir compressibility.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.