Importance of Collecting Dimensional Information From Modern Analogs for Use in Ancient Carbonate Reservoir Characterization

Abstract

Abstract

Hydrocarbon fields in carbonate reservoirs represent a significant portion of discovered global oil reserves and carbonate plays still have huge exploration potential. Quantifying the size of discovered fields relies on accurate dimensional data to constrain the volumetric calculations. Carbonate plays are complex and their characterization requires varying amounts of information. Accurate geologic modeling is essential for quantifying and classifying existing or prospective fields. Insights gathered from modern and ancient datasets can be used to make predictions and guide geologic model inputs where seismic or well information is limited or absent. This type of synthetic integration of data is applicable at multiple levels ranging from microscopic rock properties measured from cores, to one-dimensional wellbore information, to two-dimensional outcrop geometries, to macro-sized (10s of meters to kilometers) seismic- or satellite-derived dimensions.

A common data gap in ancient carbonate reservoirs is macro-scaled areal or three-dimensional information. Modern day analogs can be a valuable resource for filling data gaps in the absence of seismic. Dimensional information collected using remote sensing images (e.g. LandSat, Quickbird) of modern carbonate platforms, is one way to provide a spectrum of information that can be utilized in ancient carbonate reservoir characterization. Different color bands and combination of bands from remote sensing images can be “binned” in different ways to mimic actual sizes and shapes of geologic bodies. These geobodies can be calibrated with actual sediment samples resulting in a database of depositional environment maps. Based on these maps, important dimensional data such as sizes, areas, shapes, geometries, degree of asymmetry, distributions and distances are cataloged in a modern analog database. This database is used to supplement information in data-challenged carbonate reservoirs, and as the database matures, better captures ranges in dimensions used in geologic modeling.

The use of this modern dimensional information leads to more accurate volumetric resource assessments and ranges of uncertainty along with a better prediction of facies and reservoir connectivity. This guides successful field management strategies by optimizing well spacing resulting in improved productivity.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016