Abstract
The present work focuses on the upper Cretaceous (Cenomanian-early Campanian) carbonate successions in selected wells from northwestern Iraq. These successions are represented by Gir Bir (Cenomanian-early Turonian), Wajna (late Santonian) and Mushorah (early Campanian) Formations. The succession has affected by early burial near-surface, unconformity-related and deep burial diagenesis represented by cementation, neomorphism, dolomitization, dedolomitization, silicification, authigenesis of glauconite and pyrite, compaction, micritization, solution and porosity formation. The common porosity types are intergranular, fenestral, intercrystalline, moldic, vuggy, channel and fracture. Three porosity zones (I, II, and III) are identified depending on variation in gamma ray which reflects their shale content. The upper part of zone (II) is highly porous and regarded on the main reservoir unit in the middle and upper parts of the Gir Bir Formation. Fracture and moldic and vuggy dissolution features in addition to karstic and fissure features are responsible for the porosity increase in the fractured reservoir unit.
Highlights
The Mesozoic carbonate system of the Arabian Plate is one of richest hydrocarbon provinces of the world
The present work focuses on the upper Cretaceous (Cenomanian-early Campanian) successions in selected wells from northwestern Iraq
The skeletal grains of the Gir Bir Formation are dominated by benthic foraminifera (Miliolids, Alveolina, and Orbitolina) and rudist while the non-skeletal constituents are represented by pelloids and lithoclasts
Summary
The Mesozoic carbonate system of the Arabian Plate is one of richest hydrocarbon provinces of the world. This is mostly due to combination of their large-scale dimensions and the presence of source and seal rocks within the same depositional system [1]. The present work focuses on the upper Cretaceous (Cenomanian-early Campanian) successions in selected wells from northwestern Iraq. These successions are represented by Gir Bir (Cenomanian-early Turonian), Wajna (late Santonian) and Mushorah (early Campanian) formations. Carbonate rocks of the Gir Bir Formation are represented by limestones (mostly recrystalized), marly limestone and fractured dolomite. The Mushorah carbonates are based on conglomerate and brecciate bed, poorly sorted with subroundedsubangular rock fragments in a green marl matrix
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
