Natural Radionuclide Analysis on Crude Petroleum from Some Oil Fields in Ghana

Abstract

The petroleum industries benefit immensely from developing scientific processes and procedures that determine characteristics of crude oils and distinct them. This is because crude oils are acquired from various geological sources and each sedimentary rock has its own distinct chemical properties that affect extraction, refinery and environmental safety. Extraction of crude oils may result in exposure of some radionuclide elements from sedimentary rocks into the environments. This nuclear exposure may affect lives and can cause ecological imbalance. Applications of gamma emission spectroscopy has grown rapidly around the world because of its accurate measurement and precision. Such technique has not been applied for the study of naturally occurring radionuclide materials (NORMs) in crude oils from the active oil fields in Ghana. The study employed the use of gamma spectroscopic technique for characterization of crude oil samples from Jubilee Oil Field, Tweneboa Enyenra Ntomme (TEN) Oil Field and Saltpond Oil Field. The technique was applied on four crude oil samples. The results of this paper actually report on radionuclide concentrations of naturally occurring radioactive materials in four crude samples using a Gamma-Ray spectrometer. Three radionuclides, radium-226 (226 Ra), thorium-232 (232 Th) and potassium-40 (40 K), were identified from each crude sample (JF, TF SF-1 and SF-2). It was observed that samples from Saltpond Oil Field estimated the highest activity concentration and the least was crude oil from Jubilee Oil Field. The activity concentration values were far less than the approved values by International Atomic Energy Agency for basic safety standard. Therefore, the radionuclides activity concentration values of crude oil samples from Jubilee, TEN, and Saltpond oil fields were within the basic safety standards exemption levels of the International Atomic Energy Agency (IAEA). The crude oils from the oil fields can therefore be considered safe to handle. Also, the results of the activity concentrations from the sample used for this study indicate that crude petroleum from the oil fields may relatively have little nuclear activity impact to ecology and human health. The result of this study may be adopted by the Environmental Protection Agency and the Petroleum Stakeholders of Ghana for development of petroleum geo-radionuclides radiation safety measures.