Petroleum system in supra-salt strata of extensional forced-folds: A case-study from the Basque-Cantabrian basin (Spain). (September 2018)

• Record Type: Journal Article
• Authors: Tavani, S.; Balsamo, F.; Granado, P.
• Is Part Of: Marine and petroleum geology. Volume 96(2018)
• Page Start: 315
• Page End: 330
• Publication Date: 2018-09
• Subjects: Forced folding -- Fractures -- Basque-Cantabrian basin -- Inversion tectonics; Submarine geology -- Periodicals; Petroleum -- Geology -- Periodicals; Géologie sous-marine -- Périodiques; Pétrole -- Géologie -- Périodiques; Petroleum -- Geology; Submarine geology; Periodicals; Electronic journals; 551.468
• DOI: 10.1016/j.marpetgeo.2018.06.008
• Languages: English
• ISSNs: 0264-8172

Abstract

Abstract: Hydrocarbon accumulations in the Plataforma Burgalesa are located in structural traps that resulted from Mesozoic extensional forced folding. Pre-rift Triassic evaporites favoured the structural decoupling between faulted basement rocks and their supra-salt cover, which includes carbonate and fluvial reservoirs. These reservoir levels record severe syn-extension fracturing, related to the stretching of the supra-salt layers as extensional forced folding proceeded. The observed syn-extension fracture pattern has been partly modified by subsequent Cenozoic shortening. The availability of a large data set of seismic profiles, well data, oil shows, and the exposures of reservoir and seal levels, make the Plataforma Burgalesa an outstanding analogue for petroleum plays in extensional settings with supra-salt reservoirs. Here, we provide a reassessment of recently published structural data from the area, including geometry, kinematics, and fracture pattern of the partly inverted extensional forced fold system. We then compare structural features and occurrence of hydrocarbon accumulations, to discuss the implications for structural traps formation in rift basins with an intermediate décollement level. Highlights: The petroleum system of the Plataforma Burgalesa of northern Spain is described. Structural traps are associated with Mesozoic extensional forced folding. Syn-extensional fracturing improved the quality of pre-rift carbonate reservoirs. Cenozoic inversion amplified the structural traps.