Sequence Stratigraphy, Palaeogeography and Petroleum Plays of the Cenomanian – Turonian Succession of the Arabian Plate: An Updated Synthesis

Abstract

The Cenomanian -Turonian succession of the Arabian Plate By contrast in the Najaf intrashelf basin (Iraq), there is a significant siliciclastic component sourced from the Arabian Shield. This influx resulted in a mixed carbonatesiliciclastic ramp depositional system on the proximal, western margin of the basin, and an apparent absence of organic-rich intervals within the central basin succession. Grainy carbonate reservoir rocks are restricted to the eastern margin and are charged by older source rocks within the underlying stratigraphy.The GDE maps record the configuration of these petroleum systems elements within the Cenomanian-Turonian interval and form the basis for play screening. The Cenomanian-Turonian interval is punctuated by the major mid-Turonian unconformity which is a tectonostratigraphic boundary of considerable geological and economic significance. In the southern and eastern part of the Arabian Plate, this unconformity has a differential erosion profile that facilitates a subcrop play with exploration potential. Identifying subtle stratigraphic traps is challenging, but by combining GDE facies with the mapped preservation limit for each sequence, it is possible to identify areas where rudist-rich reservoir facies with potential karst enhancement are overlain by a regional claystone seal, high-grading areas with subcrop trap potential.

High‐magnesium calcite skeletons provide magnesium for burrow‐selective dolomitization in Cretaceous carbonates

“…Stratigraphic synthesis for the Upper Albian to Lower Turonian of south‐eastern Arabia (modified after Bromhead et al ., 2022). The red line segment shows the Rumaila Formation in this study.…”

“…In this study, the Rumaila is stratigraphically equivalent to the Rumaila and lower‐middle Mishrif formations in southern Iraq, the Dokan Formation in northern Iraq, the upper Sarvak Formation in south‐western Iran, the Magwa Formation in Kuwait, the Khatiyah and Mishrif formations in Qatar, the Rumaila and Mishrif formations in Saudi Arabia, and the upper Natih Formation in Oman, as well as the mid‐upper Mishrif and Shilaif formations in the United Arab Emirates (Fig. 2) (Philip et al ., 1995; Aqrawi et al ., 1998; Sharland et al ., 2001; Davies et al ., 2002; van Buchem et al ., 2002, 2011; Razin et al ., 2010; Bromhead et al ., 2022). These strata are of great interest because they comprise important hydrocarbon reservoirs in the Middle East, particularly in Iraq, where ca 30% of the country's hydrocarbon reserves are contained within these strata (Aqrawi et al ., 2010).…”

Evidence for Isolated Platform Development in the Cenomanian on the Passive Margin of Neotethys, Southwest Iran

“…Thus, the Sarvak Formation and its equivalents comprise significant reservoir intervals in the S and S.W. of Iran (including the Lurestan Zone) and throughout the Middle East [25,[30][31][32][33][34][35][36] (Figure 2).…”

“…Thus, the Sarvak Formation and its equivalents comprise significant reservoir intervals in the S and S.W. of Iran (including the Lurestan Zone) and throughout the Middle East [25,[30][31][32][33][34][35][36] (Figure 2). Facies distribution and reservoir characteristics of the Sarvak Formation vary significantly in different regions of the Zagros due to the influence of several geological factors [37][38][39].…”

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“…The Cenomanian also represents the stage that contains "the largest number of genera that possess stratigraphic ranges restricted to a single stage", so-called singletons (Kaminski et al, 2008, p. 10). In Iran, the Cenomanian-Turonian Sarvak Formation represents the most prolific regional oil reservoir, second only to the Oligo-Miocene Asmari Formation, deposited on a carbonate platform that was located on the passive margin of the Arabian Plate (Ziegler, 2001;Bromhead et al, 2022). It mostly consists of shallow water carbonates exhibiting diverse foraminiferal assemblages, associated with calcareous green algae (e.g., Salpingoporella pasmanica Radoičić) and rudist bivalves, among other components.…”