Print this pageFUGITT, DAVID S., Chevron North America E&P
Co., Lafayette, LA; CHARLES E. STELTING, Chevron 
Production
Technology
Co., New Orleans, LA; WILLIAM J. SCHWELLER, Chevron petroleum Technology
Co., La Habra, CA, JAMES E. FLORSTEDT, GARY J., HERRICKS and MICHAEL R.
WISE, Chevron North America E&P Co., Lafayette, LA
Abstract: Production Characteristics
of Sheet and Channelized Turbidite Reservoirs, Garden Banks 191, Gulf of
Mexico, USA
Garden Banks 191 is 160 mi from Lafayette,
Louisiana in 700 ft of water. Block 191 has produced over 210 BCF dry gas
from Pleistocene reservoirs since 1993. This paper will address the production
characteristics of turbidite sheet (4500' Sand) and channel (8500' Sand)
sand reservoirs. Understanding the distribution of shale breaks within
both reservoir types is critical because the shales compartmentalize gas
production and control water encroachment.
The 4500' Sand reservoir is composed of 1000 ft
of interbedded sands and shales typical of amalgamated and layered sheet
sands. The sand is subdivided into four production
members (designated
1-4) by shale breaks that extend across the reservoir interval. The reservoir
has exhibited a good water drive. Water encroachment occurs individually
within each member.
The 8500' Sand is an approximately 900 ft. thick
"fining-upward" channel succession that was deposited in a slope minibasin
formed by salt withdrawal. Shale breaks in this stacked channel succession
do not extend across the reservoir, but they do control water encroachment
in individual wells. The sand is informally divided into five members based
on shale breaks and perched water contacts. Members 3, 4 and 5 are connected,
based on RFT pressures. The 8500' Sand has produced from a combination
pressure depletion/limited water drive mechanism resulting in excellent
reservoirs.
AAPG Search and Discovery Article #90924©1999 GCAGS Annual Meeting Lafayette, Louisiana