Reservoir Management Through an Integrated Sequence Stratigraphic and Statistical Approach for the Zechstein 2 Carbonate (Upper Permian, Northwest Germany)

Christian Strohmenger, Karen M. Love, John C. Mitchell, Konrad Rockenbauch

Sequence stratigraphic and statistically-based mineralogy, porosity, and permeability models have been integrated to improve reservoir prediction and management for the Zechstein 2 Carbonate.

A depositional model and a sequence stratigraphic framework were developed in order to improve prediction of reservoir facies. The Zechstein 2 Carbonate consists of platform, upper slope, middle slope, lower slope, and basinal facies within one complete third-order sequence (Zechstein sequence 3), as well as part of the lowstand systems tract of the overlying fourth Zechstein sequence. The Zechstein 2 Carbonate can be further subdivided into seven parasequences having diagnostic facies/subfacies succession, gamma-ray log response, and palynofacies.

Reservoir quality characterization within the Zechstein 2 Carbonate is complicated by pervasive diagenetic modifications. In particular, porosity-destroying calcitization (dedolomitization) of Zechstein 2 Carbonate slope dolomites necessitates predicting the distribution of porous dolomite versus non-porous calcite. Statistical analyses indicate that both facies and location variables (latitude, longitude, and depth) significantly predict mineralogy; furthermore, facies and location variables predict porosity and permeability directly. Combining these predictive equations with a three-dimensional facies model provides a three-dimensional reservoir model, enhancing reservoir management capabilities.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995