Aerial gamma-ray spectrometric survey data as a guide for probable hydrocarbon accumulations at Abu-Zeneima/Al-Tur area, Southwestern Sinai, Egypt

Abstract

A method using surface and aerial gamma-ray spectral measurements to explore the hydrocarbon accumulations in Abu-Zeneima/Al-Tur area of Southwestern Sinai, Egypt, was selected due to both its structural setting and its location in close proximity to the Gulf of Suez, which represents one of the important sites of oil production in Egypt.Examination of the normalized potassium map (KD %) shows low concentrations above Abu-Alaqah, Thebes, and Kariem formations, while normalized equivalent uranium map (eUD %) shows a high concentration above these formations. The Deviation of Radio-Active Derivative (DRAD) map shows some of the delineated high positive DRAD anomalies, which are elongated in the NW–SE direction and related to Abu-Alaqah, Thebes, and Kariem formations.Data from every formation and rock unit as well as each flight line were extracted in XYZ format and evaluated with simple statistical applications. The DRAD arithmetic means plus three standard deviations (x + 3s) and plus two standard deviations (x + 2s) for the data set all over the study area were computed and reached the values of 2.5 and 2.1, respectively. Any single point that possesses a value greater than these two values should have a probability of 99.7% and 95%, respectively, of possible petroleum accumulations and represents a sure anomaly. The use of these criteria helped identify Abu-Alaqah, Thebes, and Kariem formations. Moreover, five zones along four flight lines correlating geologically with Abu-Alaqah, Thebes, and Kariem formations have sure anomalies. This might indicate a prospective possibility of feasible subsurface petroleum accumulations in Abu-Zeneima/Al-Tur area, Southwestern Sinai, Egypt.