Sequence stratigraphy and paleoenvironmental progression of Abu Madi Formation in offshore Baltim East field, Nile Delta, Egypt

Understanding the subsurface depositional pattern is dramatically obtained through the sequence stratigraphic modeling. As being good hydrocarbon resources, the siliciclastic successions in the incised paleo-valleys are intended. Abu Madi Formation of the Baltim East field in the Egyptian offshore Nile Delta, is selected to apply high sequence stratigraphic resolution and determine paleoen-vironmental progression. Sequence stratigraphic analysis determined distribution of the hydrocarbon bearing sands within the Messinian Abu Madi incised valley. Wireline log tools are used, and the log readings are processed with the statistical multivariate techniques (CONSLINK) to outline the electric lithofacies distribution that make up sequence cycles. Two sequence cycles are recognized; lower (SQ-L) and upper (SQ-U). Lowstand, transgressive and highstand systems tracts are indicated in both sequences. The fluvial lowstand systems tracts (LSTL, LSTU) represent the sandstone gas reservoirs within Abu Madi Formation. Recognizing the organic matter distribution in the context of palynofacies variations enabled to determine the paleoenvironmental progression related to changes in relative sea level. Palynofacies analysis indicated that the deposition of Abu Madi Formation was in the proximity to sources of the terrigenous material (fluvio-deltaic or river mouth) with active fresh water inputs in oxic conditions. There is a general trend of upward relative sea level rise indicated by increasing percentages of phytoplankton palynomorphs, sporomorph and small-sized opaque, high buoyancy phytoclasts. The progression of the depositional environment indicates regressivetransgressive trend through change from onshore deltaic to offshore setting.