From thin sections to discovery: the Upper Satal in the central Sirte Basin (north-central Libya) a success story
Carbonates of the Lower Palaeocene Upper Satal Formation form a major hydrocarbon reservoir in the central Sirte Basin in northern Libya (e.g. in the Mabruk, Bahi, Ali, Almas, Arbab oil fields). All fields are aligned along a WNW-ESE trend, which is interpreted as a reef and shoal belt facies zone tracking a seaward carbonate platform margin, which can be followed across the Dahra-Hofra Platform. However, existing 2D seismic and well data indicated that this prospective trend could possibly extend further west into the Dor Al Abid Trough. To test this hypothesis, extensive new 3D seismic was acquired and incorporated into the concept of the ,,Dynamic Stratigraphy”. This concept implies a systematic and process-based analysis of sedimentary sequences along a hierarchy of spatial and temporal scales, moving from smaller (e.g. facies, sequence analysis) to larger levels (e.g. stacking pattern, basin analysis). With the results of this detailed analysis it was possible to follow the Upper Satal prospective trend through the Dor Al Abid Trough and to identify an Upper Satal prospect, which was successfully tested by a new field wildcat.