Paleogene Carbonate Reservoirs (Spain)

Spectacular rock exposures of transgressive to highstand carbonate platforms and intervening clastic lowstand systems will be examined during the present field course in the southern foothills of the Pyrenean mountain belt, in North-Eastern Aragon. These sedimentary rocks are of Late Paleocene to Early Eocene age (approx. 56 to 53 million years old), and are outcropping approx. 170 km north-west of Barcelona, in the Rio Isabena Valley (near Roda).

During Paleocene to Eocene time, the area was situated on the tectonically active, northern margin of the Central-South-Pyrenean Basin, where tectonics had a major influence on palaeo-geography and carbonate depositional systems.

Contrasting types of carbonate build-ups developed successively on the compressional growth structures near the active margin of the Central South Pyrenean Basin.

Syn-sedimentary tectonics, eustatic level changes and combined paleo-biologic evolutions were the main factors controlling the facies architecture of these carbonate build-ups.

In terms of reservoir architecture, these build-ups are compelling analogues to Paleocene and Eocene subsurface targets, in North Africa and the Middle East. Their stratigraphic complexity remains undetected by 2D seismic, and can only be partially seen in 3D high-resolution seismic. Becoming aware of the complex 3D stratigraphic architecture of these carbonate systems is essential in order to build the right field development strategy.

During the excursion, participants will learn how carbonate facies analysis and high-frequency sequence stratigraphy can be applied to decipher the architecture of these carbonate platforms.

This course is for any geoscientist/reservoir engineer or any geosciences student knowing the basics of sedimentary geology and the fundamentals of carbonate reservoir characterization.

Participants will examine:

• Lower Tertiary Platform-Edge Reefs - Platform-Edge Sand-Lobes - Platform-Interior Sand-bodies - Isolated Reef Mounds.
• Transgressive Carbonate Sand-Sheets (“Drowned Beaches”) ? Condensed-Sections at Maximum-Flooding.
• Nummulites Banks ? Off-Bank Bioclastic Sand-Sheets.
• Lowstand Clastics.

In order to learn how to extrapolate from core data to potential subsurface reservoir geometries, participants will analyze and determine:

• Carbonate Facies, Facies Associations and Genetic Facies Sequences;
• Potential Reservoir Flow-Units versus Reservoir Heterogeneities;
• The influence of Syn-sedimentary Tectonics on the Geometry of Depositional Sequences and embedded Potential Reservoirs.

• “Learning-By-Doing” approach involving all participants.
• Outcrop examination of carbonate depositional systems at various scales.
• Introductory lecture on the Geological evolution of the Central South Pyrenean mountain belt.
• Outcrop analysis combined

Three full days on the field (2 half days car-transfer to and from outcrop area with “drive-on” information)