3D Slicing of Radiogenic Heat Production to Distinguish Source and Reservoir Rocks of Al-Wastani Formation, Sapphire Oil Field, Deep Marine Nile Delta, Egypt

Abstract

Total gamma ray logs of Al-Wastani Formation clastic sediments were normalized across seven wells in the Sapphire oil field, situated in the deep marine area of the Mediterranean Sea, Egypt, to facilitate the computation of radiogenic heat production (RHP). The gamma ray logs were normalized via the Histogram method by manually modifying values for each well, with modifications varying from (-6 to +6) API.

The Arithmetic mean and standard deviation of RHP values, which range from 0.05 to 1.67 µW/m³ were calculated as 0.71 µW/m³ and 0.23 µW/m³ respectively as established through statistical analysis of the data. Considering the strong relationship between RHP and hydrocarbon composition, the three-dimensional slicing of radiogenic heat production reveals that the upper portion of the Al-Wastani Formation constitutes a free-hydrocarbon zone. Hydrocarbons are present in both the intermediate and lower strata. Hydrocarbons are distinctly associated with reservoir rocks in the middle region of the Al-Wastani Formation. The lower layer of the Al-Wastani Formation is considered a source rock.