Jean-Christophe Navarre1, Alain Michot1, Dan Diluzio1
(1) TotalFinaElf USA, Houston, TX
The main reservoir interval of Matterhorn Field (Mississippi Canyon 243) corresponds to a late Pliocene depositional turbiditic system. Four prospective intervals have been discovered, 55% of the current reserves are found in the shallow turbiditic system A.
The sedimentary interpretation is based on one cored interval, 3 wells and a 3D seismic survey.
The turbiditic system A, 2 miles wide and 400 ft thick, is composed of three channel complexes laterally and vertically stacked limited at the base by erosive surfaces. The erosive channel complexes Aa and Ab are both 1 mile wide and 200 ft thick. They are filled by amalgamated sandy channel stories associated with spill phase deposits. The top of channel complexes Aa and Ab, composed of stacked spill phase sandy deposits, are connected as demonstrated by pressure data. The channel complex Ac is 1 mile wide and 200 ft thick. It erodes the western side of the channel complex Ab. The channel complex Ac is composed of degraded constructive and levee deposits.
Based on these sedimentary interpretations, the 3D seismic volume, limited by the base and the top of the depositional system, was divided into 7 layers, each 15 ms thick. Various seismic attribute maps were calculated and interpreted in conjunction with careful analysis of seismic profiles and stratigraphic position to generate sedimentary facies maps. Well log data, amplitude characters and seismic inversion tools were used to define reservoir properties such as net/gross for each sedimentary facies. The contour map of each facies was transferred in the reservoir model software to define the gridding.
The understanding of different scale of reservoir architecture and the description of distribution, continuity and connectivity of sand/shale bodies is an invaluable aid to constrain the gridding of the reservoir model and to predict reservoir quality where calibration are missing.
AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado