A carbonate well was drilled in a field with complex geological formations, revealing a substantial anhydrite interval that extends approximately 900 feet. This interval was homogeneous, as confirmed by gamma ray, sigma, spectroscopy, and resistivity measurements. Accurate density measurements of this anhydrite were crucial, as it acts as a structural reference marker. Traditionally, these density measurements have relied on radioactive sources.However, thanks to advancements in tool hardware and digital modeling capabilities, a new sourceless neutron gamma density (SNGD) measurement was developed in NovoSphere service, eliminating the need for radioactive sources.
NovoSphere sourceless formation evaluation logging-while-drilling service delivered accurate measurements in high-density anhydrites. SNGD measurements taken with the service were consistent with gamma gamma density (GGD) measurements, confirming the effectiveness of the new measurement in accurately characterizing anhydrite formations in wells. This innovation enhances safety and efficiency while maintaining the accuracy required for effective petrophysical analysis.
