Radiogenic Heat Production and Reservoir Properties of Rudeis Formation in Belayim Marine Oil Field, Gulf of Suez, Egypt

Abstract

This thesis commences with an overview of the Stratigraphy and geological setting of the study area with more emphasis about the area under consideration. In the study area, the Rudeis Formation is recoded in all wells BM-30, BM-35, BM-37, BM-57, BMNW-2, BMNW-3, 113-M-27, 113-M-34, and 113-M-81. Thickness varies between 134 m in BM-30 to 615 m in BM-35, and lithologically Rudeis Formation consists mainly of sandstones with little shale. The study is primarily based on borehole logging data. The objectives of this study were to estimate the Radiogenic Heat Production from two different sets of data, radioactive characteristics and evaluate the reservoir properties of Rudeis Formation Rocks in Belayim marine oil field, Gulf of Suez, Egypt. The available data include well logging data of nine wells, seven of them possessed spectral gamma-ray log data (SGR) of the Rudeis Formation rocks in the study area. The distributions of each radioactive element in the Rudeis Formation rocks were analyzed by two methods, the statistical analysis and histogram. The thorium-potassium cross plots for all seven wells are presented in order to identify the clay minerals in the Rudeis Formation rocks. The main clay minerals in Rudeis Formation of the studied wells consist of montmorillonite, kaolinite, chlorite and mixed clay layer with some traces of illite and glauconite clay minerals. The radiometric studies of the Rudeis rocks in the study area show that, the concentration of radioactive minerals is in the normal range. Radiogenic heat production estimated from the concentrations of the radioactive elements and gamma-ray intensity obtained from SGR, and GR logs respectively recorded in the Rudeis Formation, and a 3D block of radiogenic heat production was constructed from those two sets of data. Plotting the reservoir RHP in the form of 3D gives a clear picture about the distribution of Radiogenic Heat production in all parts of the Rudeis Formation in the study area. The north and northeastern parts of the study area have showed the highest radiogenic heat production than the other parts. Heat production estimated from gamma-ray Intensity was moderately correlated with those estimated from the concentrations of radioactive elements. The average radiogenic heat generation produced from the study area is calculated as 1.2 KW. A considerable amount of geological information required for subsurface reservoir characterization of new and old hydrocarbon fields can be attained by analyzing critically well logging data. Digitizing, gathering well logging data and applying environmental corrections are important to give an accurate log analysis as well as to generate vertical lithological logs of the subsurface. Multiwell normalization is necessary to ensure that the results are accurate, consistent and comparative from well to well, by using histograms. Iso-parameter maps for estimating the clay volume, porosity, net pay thickness, water saturation, hydrocarbon saturation, oil in place and pie charts were prepared for use in predicting the distribution of reservoir properties in Rudeis Formation. These maps in addition to the decision map provide a quick method of estimates hydrocarbon field. The study yields important reservoir parameters which can assist reservoir engineers for further development and enhance oil recovery (EOR).