Claudia Rassi and Tucker F. Hentz1
Sequence stratigraphy has been related to reservoir quality by predicting production characteristics of fourth-order sequences and systems tracts. This assumption was tested on a complete production-history dataset of two mature fields offshore Louisiana. Data from Starfak and Tiger Shoal fields include logsuites, sidewall cores, and production information from ~150 wells (approximately 270 producing zones) that have been correlated within a sequence-stratigraphic framework of fourth-order sequences and systems tracts. Noncommingled production data on cumulative and monthly production (per well and horizon), current status of well and each producing horizon (as of July 2000), and additional information, such as well tests and packer positions, were available for the Miocene-age reservoir sands. These production data were correlated to the fourth-order systems tracts.
The various and statistically representative data for the systems tracts (lowstand, transgressive, and highstand) were differentiated by lithological characteristics, facies associations, and production behavior. The purpose of this effort is to link these properties with production performance, which required an investigation of each perforated and producing zone. Several factors can influence the accuracy of this compiled information. Production rates can be affected by geological (facies, lithology) and mechanical (downhole equipment) conditions or economic reasons and may therefore vary accordingly. Our conclusion is that selected characteristics of fourth-order systems tracts can be used to predict production characteristics.
1Bureau of Economic Geology, The University of Texas at Austin, University Station Box X, Austin, Texas 78713