Geological Evolution and Hydrocarbon Potential in the Balearic Basin (Spain)

Paolo Esestime, William W. Reid, Phillip J. Hargreaves, and Neil Hodgson

The hydrocarbon potential of the offshore Balearic Basin, Western Mediterranean has been investigated utilising 12,000 Km of 2D marine seismic reprocessed Spectrum (SP-BAL and MEDS-77), located offshore Catalonia and Valencia, and around the Balearic Archipelago. The seismic has been calibrated with ten wells and integrated with outcropping geology, to constrain the distribution and the geological evolution of both the wellknown and potential hydrocarbon plays.

In the coastal region, the Mesozoic sequence is the most prolific hydrocarbon play, proven by economical oil discoveries such as Amposta, Casablanca, Terraco and Dorada. These significant discoveries have a Cretaceous shallow water limestone reservoir, sourced by marine Jurassic marls and shales.

The Mesozoic plays were primarily controlled by a Triassic-Early Jurassic rift, and the Lower Cretaceous evolution of Eastern Iberia paleomargin. Subsequently the paleogeography evolved as foreland/foredeep basin during the Tertiary shortening of the surrounding mountain ranges (Pyrenees, Betic Cordillera and Western Alps).

In the deepwater basin east of the coastal margin, potential source rocks and deepwater clastic reservoirs were deposited unconformably over the incised Mesozoic and the Palaeozoic Terrane.

Subsequently the Neogene sequence was deposited comprising over 2000m of clastic deposits including over 300m of Messinian Halite, forming a ‘salt canopy’. This ‘salt canopy’ has allowed the hydrocarbons from the underlying basin to migrate along its margins, and around halokinetic salt welds into 4-way dip closed traps within the post halite sediment.

Well imaged in the seismic, The Neogene sequence was deposed in the tensile regime associated with counter clockwise rotation of the Sardinia-Corsica block, in the upper Oligocene-Miocene. Limited Palaeogene shortening and the lack of additional Neogene continental rifting allows the Mesozoic units to be traced distally in the seismic, showing thicknesses of about 3000-4000m, and revealing additional petroleum potential in the Mesozoic across the entire continental shelf of the Balearic Basin.

AAPG Search and Discovery Article #90161©2013 AAPG European Regional Conference, Barcelona, Spain, 8-10 April 2013