# AAPG Bulletin

Abstract

AAPG Bulletin, V. 97, No. 5 (May 2013), P. 845871.

DOI:10.1306/10231212039

## Outcrop analog for an oolitic carbonate ramp reservoir: A scale-dependent geologic modeling approach based on stratigraphic hierarchy

### Frederic Amour,1 Maria Mutti,2 Nicolas Christ,3 Adrian Immenhauser,4 Gregory S. Benson,5 Susan M. Agar,6 Sara Tomas,7 Lahcen Kabiri8

1Institute of Earth and Environmental Science, Potsdam University, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam-Golm, Germany; amour@geo.uni-potsdam.de
2Institute of Earth and Environmental Science, Potsdam University, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam-Golm, Germany; mmutti@geo.uni-potsdam.de
3Faculty of Earth Sciences, Ruhr University, Universitatsstrasse 150, D-44801 Bochum, Germany; Nicolas.Christ@ruhr-uni-bochum.de
4Faculty of Earth Sciences, Ruhr University, Universitatsstrasse 150, D-44801 Bochum, Germany; adrian.immenhauser@rub.de
5ExxonMobil Upstream Research Company, P.O. Box 2189 URC-SW 639, Houston, Texas 77252; Gregory.S.Benson@ExxonMobil.com
6ExxonMobil Upstream Research Company, P.O. Box 2189 URC-SW 639, Houston, Texas 77272; susan.m.agar@exxonmobil.com
7Institute of Earth and Environmental Science, Potsdam University, Universitatsstrasse 150, D-44801, Potsdam-Golm, Germany; stomas@geo.uni-potsdam.de
8Faculty of Science and Technology, Moulay Ismail University, BP509 52000 Boutalmine, Errachidia, Morocco; Kabiri_lahcen@yahoo.fr

## ABSTRACT

Considerable effort has been devoted to the development of simulation algorithms for facies modeling, whereas a discussion of how to combine those techniques has not existed. The integration of multiple geologic data into a three-dimensional model, which requires the combination of simulation techniques, is yet a current challenge for reservoir modeling. This article presents a thought process that guides the acquisition and modeling of geologic data at various scales. Our work is based on outcrop data collected from a Jurassic carbonate ramp located in the High Atlas mountain range of Morocco. The study window is 1 km (0.6 mi) wide and 100 m (328.1 ft) thick. We describe and model the spatial and hierarchical arrangement of carbonate bodies spanning from largest to smallest: (1) stacking pattern of high-frequency depositional sequences, (2) facies association, and (3) lithofacies. Five sequence boundaries were modeled using differential global position system mapping and light detection and ranging data. The surface-based model shows a low-angle profile with modest paleotopographic relief at the inner-to-middle ramp transition. Facies associations were populated using truncated Gaussian simulation to preserve ordered trends between the inner, middle, and outer ramps. At the lithofacies scale, field observations and statistical analysis show a mosaiclike distribution that was simulated using a fully stochastic approach with sequential indicator simulation.

This study observes that the use of one single simulation technique is unlikely to correctly model the natural patterns and variability of carbonate rocks. The selection and implementation of different techniques customized for each level of the stratigraphic hierarchy will provide the essential computing flexibility to model carbonate settings. This study demonstrates that a scale-dependent modeling approach should be a common procedure when building subsurface and outcrop models.

## Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

 Protected Document: $10 Internal PDF Document:$14 Open PDF Document: \$24