Burial and thermal maturity modeling of the Middle Cretaceous–Early Miocene petroleum system, Iranian sector of the Persian Gulf

Abstract

The Cretaceous Kazhdumi and Gurpi formations, Ahmadi Member of the Sarvak Formation, and Paleogene Pabdeh Formation are important source rock candidates of the Middle Cretaceous-Early Miocene petroleum system in the Persian Gulf. This study characterizes generation potential, type of organic matter, and thermal maturity of 262 cutting samples (marls and argillaceous limestones) from these rock units taken from 16 fields in the Iranian sector of the Persian Gulf. In addition, the burial and thermal histories of these source rocks were analyzed by one-dimensional basin modeling. Based on the total organic carbon and genetic potential values, fair hydrocarbon generation potential is suggested for the studied samples. Based on T max and vitrinite reflectance values, the studied samples are thermally immature to mature for hydrocarbon generation. The generated models indicate that studied source rocks are immature in central wells. The Gurpi and Pabdeh formations are immature and the Ahmadi Member and Kazhdumi Formation are early mature in the western wells. The Pabdeh Formation is within the main oil window and other source rocks are at the late oil window in the eastern wells. The hydrocarbon expulsion from the source rocks began after deposition of related caprocks which ensures entrapment and preservation of migrated hydrocarbon.

Prediction of vitrinite reflectance values using machine learning techniques: a new approach

“…This contains more than two-thirds of the proven oil reserves of the world (Rabbani 2007;Haghi et al 2013). Pabdeh (Paleocene), Gurpi (Campanian-Paleocene), Ahmadi member of Sarvak (Cenomanian), and Kazhdumi (Albian) are considered as the most probable source rocks of the Middle Cretaceous-Early Miocene petroleum system of the studied area (Mashhadi et al 2015). These formations are illustrated in Fig.…”

Hydrocarbon source rock potential evaluation of the Late Paleocene Patala Formation, Salt Range, Pakistan: Organic geochemical and palynofacies approach

“…The achievement of optimum thermal maturity of organic matter is essential for a rock to act as a prolific potential source rock as immature or postmature source rocks cannot generate hydrocarbons (Makky et al 2014;Mashhadi et al 2015). The thermal maturity is estimated using T max and HI from the Rock-Eval data.…”

“…In case of the Patala Formation, the T max values range from 436 • (PN-1) to 447 • C (PN-11) with an average value of 439.9 (table 1), which indicates that the organicrich intervals of the formation are thermally mature and can generate hydrocarbons if rest of the source rock prerequisites are available (figure 6). In a sedimentary basin, both the burial depth and organic matter type affect the thermal maturity levels of organic matter (Selley and Sonnenberg 2014;Mashhadi et al 2015). Here, in case of the Patala Formation, the change in thermal maturity levels is also due to change in burial depth as well as due to change in types of the organic matter (table 1; figures 3 and 6).…”

Burial, Temperature and Maturation History of Cretaceous Source Rocks in the Nw Persian Gulf, Offshore Sw Iran: 3d Basin Modelling

“…The petroleum system has recently been investigated in the NW Persian Gulf and adjacent onshore Iran as well as Iraq and Kuwait (e.g. Abdullah et al, 1997;Pitman et al, 2004;Rudkiewicz et al, 2007;Abeed et al, 2011Abeed et al, , 2012Opera et al, 2013;Mashhadi et al, 2015a;Baniasad et al, 2016Baniasad et al, , 2017Karimi et al, 2016b). In addition, a seriers of 1D and 2D basin modelling studies (Bashari, 2008;Jahantigh Pak et al, 2014;Mashhadi and Rabbani, 2015a, b;Baniasad et al, 2016) have attempted to reconstruct the burial and thermal history of Cretaceous source rocks in the NW Persian Gulf.…”