Tahoe Field Case Study—Understanding Reservoir Compartmentalization in a Channel-Levee System

Chekwube Enunwa¹, Joseph L. Razzano III¹, Asha Ramgulam², Peter B. Flemings¹, Turgay Ertekin², and Zuleima T. Karpyn^2
1Pennsylvania State University, Department of Geosciences, University Park, Pennsylvania 16802
²Pennsylvania State University, Petroleum and Natural Gas Engineering Program, University Park, Pennsylvania 16802

Normal faults and stratigraphic complexity within a channel-levee system form at least three compartments in the Tahoe Field. Tahoe lies 140 miles east-southeast of New Orleans in Viosca Knoll (VK) Blocks 783, 784 & 827 in water depths ranging from 1,200 ft to 1,600 ft. The main reservoir, termed the M4.1, is a Late Miocene sand located approximately 10,000 ft below sea-level. It was formed by turbidite flows that entered an unconfined slope setting and deposited a NW-SE trending channel-levee system. This channel-levee system is draped over an anticlinal dome and cut by normal faults. Faulting forms the updip trap in the M4.1 and plays an important role in the compartmentalization of the reservoir. Two of the reservoir compartments are separated by the levee channel which acts as a barrier to fluid flow across channel margins as evidenced by multiple pre-production pressure profiles. Differential pressure depletion experienced within the East and West Levees after two years of production implies that there is limited fluid flow across channel margins during production. Channel-levee architecture along with faulting plays a key role in the compartmentalization and trapping of hydrocarbons in the M4.1.

AAPG Search and Discovery Article #90080©2005 GCAGS 55th Annual Convention, New Orleans, Louisiana