--> Petroleum Systems Modeling and Hydrocarbon Charge Assessment in Pie De Monte Boomerang Province, Bolivia

AAPG Latin America & Caribbean Region, Optimizing Exploration and Development in Thrust Belts and Foreland Basins.

Datapages, Inc.Print this page

Petroleum Systems Modeling and Hydrocarbon Charge Assessment in Pie De Monte Boomerang Province, Bolivia


An active petroleum system is recognized by producing fields in Boomerang Pie de Monte foreland basin in stratigraphic up-dip and structural traps of Silurian-Devonian and Cretaceous formations. The area is considered as one of the most prolific gas provinces in Bolivia. However, the timing of hydrocarbon expulsion and migration versus trap formation remains unclear as confirmed by dry wells showing low gas shows of residual by-passed hydrocarbons. To reduce this uncertainty, we built a basin model that honors seismic structural interpretation and well data to simulate burial history, temperature, source rock maturity and pressure regimes through geological time. Hydrocarbon expulsion from source-rocks and further HC migration was simulated using 3D basin fluid flow modeling based on Darcy flow equation, followed by a map based fetch area trap charge assessment. The main source rock units correspond to Silurian-Devonian sequences with influence of continental-marine environments (kerogen Type II/III). Maturity trend increases from north to south due to higher burial. Two phases of hydrocarbon expulsion were recognized: one early expulsion phase from Silurian source rocks during Late Triassic and a second expulsion phase from Early Devonian source rocks during Late Jurassic-Early-Cretaceous times. Lateral long distance up-dip migration through Robore formation occurred before Andean deformation, following a northward fill and spill trap charge accumulating below Late Jurassic erosive unconformity. The Cretaceous plays were charged by vertical and lateral migration above the unconformity. The Andean deformation resulted in enhancing the structural closures and vertical migration towards Cretaceous plays. The results of this study provided to YPFB a model based approach to predict yet to find volumes in place for undrilled prospects and leads and a proposition for a future drilling strategy.