Abstract
Summary
Identifying compartmentalization and understanding reservoir structure are of critical importance to reservoir development. Traditional methods of identifying reservoir compartmentalization, such as drillstem tests and extended well tests, often become impractical in deepwater settings, with costs approaching the costs of new wells and emissions becoming increasingly undesirable. Thus, compartments often have to be identified by some other means.
Individual formation-pressure measurements, downhole fluid analysis (DFA), and geochemistry are known to provide important information about reservoir architecture. When these powerful methods are combined systematically and applied to data sets, the resulting synergy delivers a much more accurate and robust picture of the reservoir. In this paper, we review a number of case studies in which we have successfully combined continuous fluid/facies mapping, pressure-gradient measurements, DFA, and geochemistry for a reservoir-continuity assessment in a diverse range of geological settings, including a wide range of field sizes, structural environments, reservoir lithologies, and oil types. Particular emphasis is placed on comparing the strengths and limitations of the different techniques in revealing reservoir architecture, especially vertical-permeability barriers. We present a number of unambiguous cases, for which multiple data streams might be viewed as being somewhat redundant. More-ambiguous cases, in which the multiple data streams are required to make a robust assessment of key reservoir properties, are also presented.