The Yacoraite-Olmedo Petroleum System of Paraguay’s Cretaceous Basin, Pirity Sub-Basin, Exploration Potential Re-examined

Michael J. Dyer¹ and Fernando Wiens^2
1 IHS Energy, Houston, TX
² Pirity Hidrocarburos SRL, Asuncion, Paraguay

The exploration potential of the Cretaceous Basin, Pirity sub-basin of western Paraguay has been re-examined, integrating published technical information from the productive Argentine Cretaceous Basin, Olmedo sub-basin, with evaluation of seismic and well data from the non-productive, lightly explored Paraguayan Pirity sub-basin. Analysis of the technical information suggests that commercial oil and gas reservoirs are present in the Pirity sub-basin but undrilled. The Paraguayan data includes 7,652km of 2D seismic and information on the eight wildcats drilled, four of which had hydrocarbon shows. The technical information for Paraguay was furnished by Pirity Hidrocarburos SRL while the Argentine data is derived from published information and IHS Energy's Cretaceous Basin database. The sporadic, 55 year exploration effort of the Maastrichtian-Paleocene Yacoraite-Olmedo Petroleum System resulted in 30 Argentine discoveries, 174.1 MMboe, after the drilling of 163 wildcats. A criticism of the Yacoraite-Olmedo Petroleum System has been that it is a poor source rock yet the petroleum system has generated 100 MMboe in place reserves for the Palmar Largo Field located just 18km from the Paraguayan border. Field size distribution indicates the potential for many 1 MMboe to 20 MMboe yet to find fields. Paraguay is ranked by IHS Energy as having the 7th best fiscal regime in the world, the USA ranks 51st, Argentina 46th and the yet to be discovered field size distribution being more attractive to independents.