Red Sea Hydrocarbon System Focus On The Source Rock and Hydrocarbon Generation

Tammam Mohamed Tammam

Potential source rocks were identified in the Egyptian Red Sea wells. These are Middle-Late Miocene and/or Early Miocene. The former contains up to 7.0% total organic carbon (TOC) and kerogen type is I and II. TOC values in the later up to 1.0% and kerogen type is II-III.

Source rocks maturity, determined mainly by vitrinite reflectance and Tmax, reveals that the studied sequences have a maturity range from marginally mature to mature and over mature only were they are affected by abrupt change associated with thermal anomaly.

Vitrinite reflectance plots, revealed two thermal events affecting the maturity. The first event is Pre-intra-Rudeis unconformity, with a gradient of 0.26 to 0.66 % Ro per 1,000 feet of burial. The later event occured at the Post intra-Rudeis unconformity with a gradient of 0.02 to 0.06 % Ro increase per 1,000 feet.

As a result of tectonism and the variation in the temperature gradients, the present top oil window varies in depth from 1540 to 3505 m and the hydrocarbon generation modelling suggests that, the generation may have occured during Late Miocene time and is still going on.

Rock-Eval analysis indicates that there is ample evidence of hydrocarbon migration in the region.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California