Exploration Insights May 2020

4 | Halliburton Landmark Exploration Insights | 5 SILICICLASTIC LOWSTAND EXPLORATION IN THE MIDDLE EAST Plays associated with lowstand deep-marine fan systems have long been established in many basins around the world. Typical components required to generate a working siliciclastic lowstand play include: the deposition of coarse- grained siliciclastic sediment on a basin floor at the edge of a slope; the presence of an up-dip seal; and overlying shales that act as a top seal. Siliciclastic lowstand exploration in the Middle East is not a completely new concept. In Abu Dhabi, the Late Cretaceous Tuwayil Formation sandstone provides the siliciclastic lowstand reservoir to the Dhafra Field (Azzam, 1995). The siliciclastic sediments of the Tuwayil Formation comprised a deltaic wedge that prograded during a forced regression. This is in contrast to the lowstand basin floor sands discussed in the rest of this article. In the Middle East, siliciclastic lowstand plays are underexplored. Most plays currently producing in the Middle East are dominated by carbonate reservoirs situated in structural traps. The majority of these traps have been drilled, so locating subtle stratigraphic traps is of vital importance to replenish hydrocarbon reserves in the region. In order to predict further siliciclastic lowstand potential in the Middle East, this article will focus on the Early Cretaceous (late Valanginian– Barremian) siliciclastic pulse, which deposited the Zubair Formation (Figure 1) in the northern Arabian Gulf. We will assess the application of Earth systems modeling (ESM) as a new technique to identify remaining prospectivity. The Mesozoic and Cenozoic stratigraphy of the Middle East is carbonate-dominated. However, there are also some key siliciclastic intervals (Figure 1) that are associated with major unconformity surfaces, such as: WHAT IS EARTH SYSTEMS MODELING? » » Mid-Cretaceous Burgan Sandstone » » Early Cretaceous Zubair Formation As the Middle Eastern petroleum province matures, new techniques are required to identify remaining exploration potential. Earth systems modeling (ESM) uses an understanding of paleogeomorphology to generate paleoclimatic » » Middle Jurassic Dhruma Formation » » Early Triassic Sudair Formation SAUDI ARABIA KUWAIT/ARABIAN GULF Aruma Highlighting Lowstand Exploration Potential Using Insights from Earth Systems Modeling: A Case Study from the Northern Arabian Gulf » » Late Triassic Minjur Formation Mishrif Ahmadi Wara Mauddud Wasia Burgan Shuaiba EARLY MIDDLE D7 D6 Ilam Ilam Sarvak Kazhdumi Kazhdumi Dariyan Gadvan Zubair Garau Yamama Sulaiy Hith Jubaila Arab LATE Sadi Tanuma Shuaiba Ratawi Gurpi Hartha LATE Biyadh by: Chris Gravestock and Benjamin Gréselle ZAGROS Tayarat Hanifa Tuwaiq Mtn Lst Dhruma Fahliyan Minagish Makhul Gotnia Najmah Alan Sargelu Upper Marrat Marrat Middle Jurassic Dhruma Formation Surmeh Marrat Marrat Neyriz Minjur Baluti Late Triassic Minjur Formation Butmah LATE MIDDLE EARLY Early Cretaceous Zubair Formation Hith EARLY Jilh Jilh Jilh Jilh Sudair Khuff Mid-Cretaceous Burgan Formation Khuff D Sefidar Dolomite/Dashtak C Dashtak B Dashtak A Dashtak Aghar Shale Kangan Kangan © 2020 Halliburton Early Triassic Sudair Formation Figure 1> A simplified chronostratigraphic chart for the Mesozoic of the central part of the Arabian plate, highlighting episodes of significant siliciclastic influx. Modified after Davies et al., 2019. Aerial view of the Middle East, including the northern Arabian Gulf. Source: https://earthobservatory.nasa.gov/images/13898/ dust-storm-in-southern-iraq

Exploration Insights May 2020 | Page 4