Hydrocarbon Exploration in from Intermountain Basin, the Altiplano of the Central Andes: New Play Concept and Petroleum System Logic

Wilber Hermoza¹, Patrice Baby², Justo Fernandez¹, and Elmer Martinez^1
1Perupetro S.A., Lima, Peru
²Perupetro- IRD Agreement, Lima, Peru

After the Tibet, the Altiplano basin is the largest and highest plateau of the planet; extending 1500 km- in length and 200 km in width wide with an average altitude of 3800 m. This complex Neogene intermountain basin is located between the Western and Eastern cordilleras of the Central Andes in south Peru and western Bolivia. In the Peruvian Altiplano (Titicaca basin), the earliest and only successful hydrocarbon exploration began in 1875 in Pirin (NW of Titicaca Lake). First oil discovery occurred in 1906 (Pirin oil field) at 120 m of depth. This field produced 300,000 BO of 36 °API in the early 1900′s.

Recent field works, seismic interpretation, core analysis and biostratigraphy studies permit to propose new play concepts and petroleum systems for hydrocarbon exploration. The eastern part of the Titicaca basin corresponds to the west verging Altiplano fold and thrust belt, which is approximately 50 km- wide and NW-SE oriented. Its western part is structured by an inverted Permian- Jurassic rift basin that controls the distribution of the Late Permian and Jurassic source rocks and presents high potential for hydrocarbon exploration. The Pirin oil field is located within this inverted rift system.

Two petroleum systems are related to Late Permian and Jurassic source rocks. Potential reservoirs are represented by Permian eolian sands and Jurassic Cretaceous fractured limestones and seals by shales and evaporites. The Altiplano thrust system and rift-inversion show several structural traps for hydrocarbons, and petroleum systems evolution is related to the Neogene sedimentation.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas