Predicting Reservoir Distribution From High Frequency Cyclic Events, Green Canyon 18 Field, Gulf of Mexico
Vinod R. Mathur
Recognition of high frequency (4th order) cyclic events during the Upper Pliocene Discoaster brouweri (1.88-2.08m.y.) interval provided a chronostratigraphic framework for a better understanding of distriburtion, geometry and connectivity of reservoirs in Green Canyon 18 field. This field is located approximately 110 miles offshore in the Gulf of Mexico in 700^prime-800^prime water depth. Ultimate reserves are 150 MMBOE. The producing reservoirs are associated with Upper Pliocene Discoaster brouweri, over 1200^prime thick and deposited in a mid bathyal environment. A high resolution integrated approach with regional, 3-D seismic, well logs, high resolution biostratigraphy, conventional core and FMS data was used to delineate the high frequency events. Two sequences were i entified within this interval which resulted from high frequency eustatic sea level changes. The upper sequence is further subdivided into three depositional units associated with high frequency events that apear to be more localized (parasequences). These four discrete channel complexes are vertically stacked to form a heirarchy with durations ranging from 1.87-2.08m.y. Each unit is enclosed by a flooding surface consisting of transgressive shale, resulting in partitioning of reservoirs. There appears to be better connectivity of reservoirs longitudinally along the channel axis. Lithofacies were extrapolated by seismic facies analysis, calibration to well logs and conventional cores. Seismic attribute analysis (STRATAMP) over each of the four intervals, shows a high amplitude sinuous pa tern, interpreted to be channels, 1500^prime wide and 2-3 miles long. Integration with conventional core indicated these channels to be filled with sandy/muddy slumps and debris flow.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California