Onshore Solimoes Basin in Brazil is an intra-cratonic basin

being very special in its depositional succession and its hydrocarbon accumulation mechanisms.This paper focuses on summarization of the formation and evolution of the basin

its structure and depositional characteristics and its key petroleum geologic features

as well as analysis of hydrocarbon accumulation mechanism and the main controlling factor for accumulations.The basin has experienced multiple tectonic movements

including multiple subsidence during the Paleozoic

a shear stress dominated Mesozoic age

and flexure subsidence in Cenozoic.The deformation style features in change from early normal faulting to later inversion and thrusting.The deposits in the basin are mainly of Paleozoic age

and are complicated in lithologic assemblages

consisting of siliciclastics

carbonates

evaporites

glacial deposits

igneous

etc.All the sequences are in unconformable contacts.The major source rock is the Upper Devonian shale

with high TOC value and high degree of thermal maturity.The main reservoir is the Carboniferous Jurua sandstone.The main seal interval is the Carboniferous-Permian evaporites

which is good in sealing capacity.The source rock-reservoir-seal combination is favorable.The basin has well developed structure traps

which are mainly anticlines and faulted anticlines.The petroleum geology of the basin is special in that the shallowly buried source rocks have entered gas window due to igneous intrusion.Eolian sands have good reservoir quality

with well preserved porosity due to its shallow burial depth.The unconformities and reactivated basement-rooted faults serve as the major pathways for hydrocarbon migration.The accumulation of oil and gas is controlled by the fault-related structrual traps.