Source ROCK EVALUATION AND ITS IMPLICATIONS FOR HYDROCARBONS GENERATION IN KATTANIYA AND GINDI BASIN AREA, WESTERN DESERT, EGYPT

Abstract

The present work deals with the source rock evaluation of the Jurassic and Cretaceous sequences, in eleven wells selected in the Kattnaiya High, Gindi Basin and Wadi Rayan Platform of the North Western Desert, Egypt. The study area represents part of the Qarun acreage and is bounded by latitudes 29°25'-30°00' Nand longitudes 30°20'-31°00' E.

The source rock evaluations were carried out through two ways. The frrst is the geochemical analysis, which based mainly on laboratory chemical and microscope analysis of sample sets from the wells. The second way is the wireline logging, which is based on the available well log data of the studied wells. The amount and type of organic matter and its maturity are determined from the two techniques for the Jurassic formations (Wadi Natrun and Khatatba) and Abu Roash Formation ("G", "F" and "A-E" Members) in the study area. Added to these, the subsurface geologic evaluation is carried out in terms of the thickness variations, lithofacies, structural setting and depositional environments of the encountered basins as compared to the ridge­ like area. The results and conclusions arrived through the various subsurface evaluations of the encountered stratigraphic rock units, as well as the geochemical analysis together with the well logging analysis of the studied units are considered to evaluate the source rocks and to determine the organic richness of the studied units, as well as, the effects of structural and stratigraphic implications on the source rock quality, in order to conduct more exploration activities in this area.

The geochemical results suggest that the Jurassic Formations which restricted to the northern part of the studied area, where Kattaniya Horst exists, have a good to very good potentiality to generate mainly gas at its level of thermal maturity. The recorded source rocks of the Abu Roash ''G" Member reflects that it is mixed oil and gas prone source rocks in the study area. The Abu Roash "F" Member includes source rocks with good to very good potential to generate mainly oil and is considered as strongly oil-prone source rocks (Type II Kerogen) for the most of the studied area; The geochemical investigation of the Abu Roash "A-E" Members shows that these members are considered non-source rocks in most of the study area except in the east of the central part which appear to be mixed oil and gas prone source rocks.. The wireline logs were available only for the Abu Roash Members in five wells in