2D seismic interpretation and characterization of the Hauterivian Early-Barremian source rock in Al Baraka oil field, Komombo Basin, Upper Egypt

作者：Ali Moamen^*; Darwish M; Essa Mahmoud A; Abdelhady A

来源：Journal of African Earth Sciences, 2018, 139: 113-119.

DOI：10.1016/j.jafrearsci.2017.12.010

• Komombo Basin
• Al Baraka oil field
• Seismic interpretation
• Six hills formation
• Source rock evaluation
• Egypt

Komombo Basin is located in Upper Egypt about 570 km southeast of Cairo; it is an asymmetrical half graben and the first oil producing basin in Upper Egypt. The Six Hills Formation is of Early Cretaceous age and subdivided into seven members from base to top (A-G); meanwhile the B member is of Hauterivian-Early Barremian and it is the only source rock of Komombo Basin. Therefore, a detailed study of the SR should be carried out, which includes the determination of the main structural elements, thickness, fades distribution and characterization of the B member SR which has not been conducted previously in the study area. Twenty 2D seismic lines were interpreted with three vertical seismic profiles (VSP) to construct the depth structure-tectonic map on the top of the B member and to highlight the major structural elements. The interpretation of depth structure contour map shows two main fault trends directed towards the NW-SE and NE to ENE directions. The NW-SE trend is the dominant one, creating a major half-graben system. Also the depth values range from -8400 ft at the depocenter in the eastern part to -4800 ft at the shoulder of the basin in the northwestern part of the study area. Meanwhile the Isopach contour map of the B member shows a variable thickness ranging between 300 ft to 750 ft. The fades model shows that the B member SR is composed mainly of shale with some sandstone streaks.
The B member rock samples were collected from Al Baraka-1 and Al Baraka SE-1 in the eastern part of Komombo Basin. The results indicate that the organic matter content (TOC) has mainly good to very good (1-3.36 wt %), The B member samples have HI values in the range 157-365 (mg HC/g TOC) and dominated by Type kerogen, and is thus considered to be oil-gas prone based on Rock-Eval pyrolysis, Tmax values between 442 degrees and 456 degrees C therefore interpreted to be mature for hydrocarbon generation. Based on the measured vitrinite equivalent reflectance values, the B member SR samples have a range 0.7-1.14%Ro, in the oil generation window.

• 出版日期2018-3