Abstract: New Tertiary Play-Fairways of The Zagros Region in Iraq

AL-GAILANI, MOHAMMAD

Until recently, it was customary in Iraq to target the crest of anticlines for new exploration targets. However recent seismic exploration in the Zagros region of northeast Iraq have proven the presence of duplex structures; where inversion, variable in strength, had taken place. These duplex structures are probably the result of movements along deep-seated faults sailing above the crystalline basement. Also, the presence of salt beds in the Tertiary sequence acted as lubricants, easing the movements while creating passive and active roofthrusts, and causing structural duplexes in nearby flanks. The presence of the upper Jurassic - Lower Cretaceous rich source rocks at around 4000 meters deep have acted as source kitchens for generating the various hydrocarbons present in the Tertiary traps. These rich source rocks have contributed to the generation of hydrocarbons in the form of light crude, condensate and gas that are characteristic of the crude discovered in the Zagros fold belts of Iraq. The migrated hydrocarbon pathways are situated along deep seated inverted faults acting as avenues and conduits for the generated hydrocarbons feeding the traps above in the readily developed fold crests and duplex structures. Various play-fairways have been identified within the Tertiary prospects which could have far reaching implications for future exploration in Iraq. Substantial columns of net pays have been tested along the flanks, and in nearby synclines in duplex structures, adding a new dimension to the exploration potential of northeast Iraq.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria