Cretaceous Palynology of the GPTSW-7 Well: Western Desert, Egypt

The palynological, palynofacies and organic geochemical analyses of 71 subsurface cuttings and 3 core samples from the GPTSW-7 well, Western Desert, Egypt, allowed the recognition of 5 biozones and 3 subzones. The combined optical (Spore colouration, palynofacies and vitrinite reflectance (Ro) and chemical (TOC and Rock-Eval pyrolysis) studies showed that, the Abu Roash and Bahariya formations, are primarily of kerogen III type, and hence gas-prone. The Abu Roash "F" Member contains a high proportion of AOM, high TOC and low OI values, indicating a highly oil-prone facies. This may be attributed to the presence of an organic-rich black shale layer, considered to be the sedimentary expression of a short-term global Oceanic Anoxic Event (OAE2). The palynofloral and palynofacies analyses show that, the Abu Roash “A” and “C” members, represent an oxic proximal and distal shelf environment, the Abu Roash “D” and “E” members, represent an oxic proximal shelf, while the Abu Roash “F” Member, was deposited in a distal suboxic-anoxic basin, the Abu Roash “G” Member and the Bahariya Formation, were deposited in a shallow marine and shallow marine to fluvio-deltaic environment, respectively.