Spore Colour Index And Organic Thermal Maturation Studies On The Pliocene Sediments Of The El Qara-2 Borehole, Nile Delta Area, Egypt

Abstract

Eight conventional core samples from the El Qara-2 well, situated in north central Nile Delta area, Egypt, have been palynologicaly investigated for determining the thermal maturity of the Pliocene Abu Madi and Kafr El Sheihk formations, based on the change in colour of pteridophytic spores. A monotonous assemblage of miospores including Baculatisporites scabridus, Ricciaesporites sp., Foveoisporites sp., Laevigatosporites major, Polypodiaceoisporites retirugatus, Leiotriletes cf. paramaximus, Polypodiidites usmensis, and Rugulatisporites cf. trophus which suggests a ?Pliocene age. Three organic facies could be recognized: a) Immature organic facies penetrate strata down to 2000 m and are characterized by the presence of pale yellow spores, b) Mature organic facies range in depth from 2000-3155 m within the Kafr El Sheihk Formation. These facies contain light brown spores, which could be considered as good source rocks for wet gas generation, c) Metamorphosed organic facies lie between 3155-3500 m within the Abu Madi Formation with spores altered to dark or opaque brown colour. This signifies a high-carbon content which produce mainly dry gas.