Organic Geochemistry, Burial History and Hydrocarbon Generation Modelling of the Upper Jurassic Madbi Formation, Masila Basin, Yemen

Abstract

The Masila Basin is an important hydrocarbon province in Yemen but the origin of its hydrocarbons is not fully understood. In this study, we evaluate Upper Jurassic source rocks in the Madbi Formation and assess the results of basin modelling in order to improve our understanding of burial history and hydrocarbon generation. This source rock has generated commercial volumes of hydrocarbons which migrated into Jurassic and Lower Cretaceous reservoir rocks. Cuttings samples of shales from the Upper Jurassic Madbi Formation from boreholes in the centre‐west of the Masila Basin were analysed using organic geochemistry (Rock‐Eval pyrolysis, extract analysis) and organic petrology. The shales generally contain more than 2.0 wt % TOC and have very good to excellent hydrocarbon potential. Kerogen is predominantly algal Type II with minor Type I. Thermal maturity of the organic matter is Rr 0.69–0.91%. Thermal and burial history models indicate that the Madbi Formation source rock entered the early‐mature to mature stage in the Late Cretaceous to Early Tertiary. Hydrocarbon generation began in the Late Cretaceous, reaching maximum rates during the Early Tertiary. Cretaceous subsidence had only a minor influence on source rock maturation and OM transformation.

Diagenetic characteristics and reservoir quality of the Lower Cretaceous Biyadh sandstones at Kharir oilfield in the western central Masila Basin, Yemen

“…Hakimi et al (2010b) provided a basin modeling analysis of the Madbi Formation source rock in the Masila Basin of Yemen, which they noted that the oil generation Madbi source rock began during the Late Cretaceous (99-66 Ma), and reached a maximum during the Paleocene (<66 Ma; Fig. 3) (Hakimi et al, 2010b). The Naifa Formation is composed of silty and dolomitic limestone, lime mudstone and wackestone (Beydoun et al, 1998).…”

“…Most Madbi shale strata penetrated by wells throughout the East Shabowah oilfield are interpreted to be thermally earlymature to peak mature for oil generation (Hakimi et al, 2010a). Hakimi et al (2010b) provided a basin modeling analysis of the Madbi Formation source rock in the Masila Basin of Yemen, which they noted that the oil generation Madbi source rock began during the Late Cretaceous (99-66 Ma), and reached a maximum during the Paleocene (<66 Ma; Fig. 3) (Hakimi et al, 2010b).…”

“…Burial history curves with hydrocarbon zones for the Madbi source in the western central Masila Basin(Hakimi et al, 2010b).…”

Geochemical characteristics and hydrocarbon generation modeling of the Jurassic source rocks in the Shoushan Basin, north Western Desert, Egypt

“…Basin modelling is widely used to study the burial and thermal histories (Lopatin, 1971;Welte and Yukler, 1981;Waples, 1988Waples, , 1994Burrus et al, 1991;Hermanrud, 1993;Littke et al, 1994;Yalcin et al, 1997;Hakimi et al, 2010). The aim of the numerical Table 2 Bulk geochemical results of Rock-Eval/TOC analysis with calculated parameters of samples from the Khatatba Formations.…”

Petrophysical analysis of early cretaceous Saar carbonates from Sharyoof oilfield in the Masila Basin, eastern Yemen, and their impact on reservoir properties and quality

“…The produced oil at Sharyoof oilfield is intermediate oil and has a specific gravity between 28 and 32 API. The source rock is Upper Jurassic Madbi Formation (Hakimi et al 2010a), which began to generate oil began during Late Cretaceous (99-66 Ma), and reached a maximum during the Paleocene (<66 Ma) (Hakimi et al 2010b). However, the lower Cretaceous Saar Formation carbonates are represents as secondary reservoir rocks in the Sharyoof oilfield (DNO Oil Company, 1999 personal communication).…”