Structural Geometry Analysis of Khasib Formation in West Qurna I and II Supergiant Oilfields, Southern Iraq

Rafea Ahmed Abdullah; Muwafaq Al-Shahwan

doi:10.46717/igj.54.1E.5Ms-2021-05-26

Rafea Ahmed Abdullah 1Basra Oil Company, Basra, Iraq
Muwafaq Al-Shahwan Department of Geology, College of Science, University of Basrah, Basra, Iraq

DOI: https://doi.org/10.46717/igj.54.1E.5Ms-2021-05-26

Keywords: West Qurna Oilfield, Structural analysis, Geometric analysis, Fold classification, Seismic interpretation

Abstract

The West Qurna I and II supergiant oilfields are one of the largest oil-producing fields, southern Iraq. They are parts of a supergiant anticline that extends more than 120 km. This anticline is oriented north-northwest and it's included the South Rumaila, North Rumaila, West Qurna I, and West Qurna II. The aim of this study is to integrate all available data to provide a better understanding of the subsurface structure for both West Qurna I and II. 3-D high-quality seismic data (in SEGY format) that executed for both oilfields independently were used as a key tool to supply perfect structural images. In addition to Zero-Offset Vertical Seismic Profile, set of well logs and well tops from 569 wells that distributed over the study area, 423 wells are located in West Qurna I, 146 wells situated in West Qurna II. OpenWorks, DecisionSpace G1 10ep and Seismic Analysis 10ep software of Halliburton were used to perform the 3D seismic interpretation and create structure maps (in-depth domain). While the cross-sections were done by Schlumberger software (Petrel 2018). Finally, the well tops were picked using Geolog 8.0. The study concludes that the structure of West Qurna I and II can be classified as an antiform, non-cylindrical, horizontal, gentle, brachy, asymmetrical anticline.