Re-Deposited Deep Water Carbonates, Surface and Subsurface Analogues

Philippe A. Lapointe¹, Jean-Loup Rubino², Serge Ferry³, and Berengere Savary^3
1 TOTAL E&P, 64018 Pau Cedex, France
² TotalFinaElf, Pau, France
³ Universite de Lyon, Villeurbanne 69622, France

Platform-top carbonates are worldwide source of hydrocarbons but production also occurs from re-deposited carbonates in deeper water settings in the form of turbidites, breccia and olistolites. These deposits are considered as potential exploration plays in areas such as the flexural basin of the Oman Mountains front, along the Florida Escarpment (Gulf of Mexico) and the Abenaki Platform in the Canada.

The basic understanding of these specific types of deposit is significantly behind that of their siliciclastic counterparts. To address this knowledge gap, an aggressive program of outcrop studies focusing on the geometry, reservoir characteristics and sedimentological processes was devised, with comparison to exploration wells or producing field for calibration.

Through integrated studies comprising data from different parts of the world (France, Italy, Oman, Mexico, and Cuba) and various types of sedimentological processes, facies distributions were established and linked to the type of the platform margin from which they were sourced. For example, sedimentary bodies, 10 by 10km across and up to hundreds of meters thick, were studied in the Lower Cretaceous of France. Good exposures allow the study of sections across the whole depositional system, thus improving our understanding of the system and allowing the reconstruction of its internal geometry and facies association.

The results from these outcrop analogue studies are fundamental for the understanding of gravity-driven carbonate deposits, and particularly for the appraisal of the lateral extent and architecture of these sedimentary bodies. They are directly applicable to producing carbonates in Mexico and Italy, and improve exploration play concepts.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005