The 12 MHz GeoSpec instrument has improved sensitivity over the standard 2 MHz systems. The improvement is about 10 times higher while not being high enough to give significant magnetic susceptibility artefacts, particularly with shale samples. This means that comparable signal to noise ratio (SNR) measurements can be made in about one hundredth of the measurement time required on the 2 MHz allowing for new and innovative 3D NMR images.
GIT Systems 3D imaging software uses the enhanced sensitivity to give the temporal resolution required for flooding experiments. This, combined with extensive rock based imaging sequences, creates a revolution in core analysis. The NMR 3D images allow the petrophysicist to understand new and innovative things about their core. Things that cannot be seen using CT.
2D spatial T2 measurements can help scientists differentiate what fluid is held in the large pores and what is held in the small pores. In the example below, the fluid found in the small and large pores of a limestone are shown.
A 3D fast spin echo (FSE) sequence can be used to study the pore heterogeneity of the rock cores. In this example the scan was of a limestone and which showed large pore heterogeneity.