Integration of Borehole Images and Core for Depositional Environment and Sequence Stratigraphy: Case-study from Southern Iraq

The abstract for the Sixth EAGE Borehole Geology Workshop presents an integrated approach to characterizing depositional environments and high-resolution sequence stratigraphy in southern Iraq. The study leverages borehole images, core data, and conventional logs to refine facies interpretation and depositional models.

The methodology involves a structured workflow incorporating borehole image logs, core descriptions, and petrophysical data to analyze sedimentary structures, depositional environments, and stratigraphic cyclicity. The study applies Dunham classification to borehole image facies delineation and addresses interpreter bias.

Key findings highlight the depositional characteristics of three formations:

Yamama Formation (Berriasian-Valanginian) – Characterized by significant diagenetic overprint, tidal signatures, and facies continuity variations.

Zubair Formation (Barremian-Aptian) – A mixed clastic-carbonate ramp with retrogradation-progradation cycles, including estuarine, deltaic, and carbonate shelf environments.

Mishrif Formation (Cenomanian-Turonian) – Deposited in a highstand systems tract with shoals, tidal channels, and rudist buildups influencing reservoir quality.

The study concludes that integrating borehole images with core and log data improves facies interpretation, reduces uncertainty, and enhances reservoir characterization. Key stratigraphic surfaces and diagenetic processes, such as karstification, are also identified. This workflow aids in defining reservoir connectivity and depositional trends for improved hydrocarbon exploration and production.