Organic geochemistry of the middle Paleozoic Ora Formation in Iraq: Implications for source rock assessment and hydrocarbon potentiality.

The Ora Formation (late Devonian-early Carboniferous) is thought to be a potential source rocks for the Paleozoic petroleum system of Iraq. The source potential from the Ora Formation is evaluated for the first time ever in this study from western and northern Iraq which integrates data from organic geochemistry including Total Organic Carbon (TOC) analysis, HAWK pyrolysis, gas chromatography (GC), and gas chromatography mass spectrometry (GC-MS) and mineralogical X-ray diffraction and scanning electron microscopy. The shale and muddy carbonate succession within the Ora Formation from surface section in northernmost Iraq and subsurface section from two wells (Akkas-1 and Akkas -3) from western Iraq have been employed to assess the source rock potentiality, thermal maturity, kerogen type, organic content, and depositional environment.