Detection of intermolecular homonuclear dipolar coupling in organic rich shale by transverse relaxation exchange.

The mechanism behind surface relaxivity within organic porosity in shales has been an unanswered question. Here, we present results that confirm the existence of intermolecular homonuclear dipolar coupling between solid and liquid phases in sedimentary organic matter. Transverse magnetization exchange measurements were performed on an organic-rich shale saturated with liquid hydrocarbon.

Evaluation of sandstone surface relaxivity using laser-induced breakdown spectroscopy.

Nuclear magnetic resonance (NMR) relaxometry is a common technique used to assess the pore size of fluid-filled porous materials in a wide variety of fields. However, the NMR signal itself only provides a relative distribution of pore size. To calculate an absolute pore size distribution from the NMR data, the material's surface relaxivity needs to be known.

Application of binomial-edited CPMG to shale characterization.

Unconventional shale resources may contain a significant amount of hydrogen in organic solids such as kerogen, but it is not possible to directly detect these solids with many NMR systems. Binomial-edited pulse sequences capitalize on magnetization transfer between solids, semi-solids, and liquids to provide an indirect method of detecting solid organic materials in shales. When the organic solids can be directly measured, binomial-editing helps distinguish between different phases.

Updated methodology for nuclear magnetic resonance characterization of shales.

Unconventional petroleum resources, particularly in shales, are expected to play an increasingly important role in the world's energy portfolio in the coming years. Nuclear magnetic resonance (NMR), particularly at low-field, provides important information in the evaluation of shale resources. Most of the low-field NMR analyses performed on shale samples rely heavily on standard T1 and T2 measurements.

Imaging of multiphase fluid saturation within a porous material via sodium NMR.

We present in this paper a method to monitor multiphase fluid core saturation through measurement of the sodium NMR signal. In a rock core saturated with water and oil, sodium will be present only in the water phase, and therefore can be used to separate the two fluids. Two dimensional sodium images were taken to monitor the movement of brine into oil saturated rock cores.

Correlations between diffusion, internal magnetic field gradients, and transverse relaxation in porous systems containing oil and water.

The main focus in this study is to investigate the correlations between internal magnetic field gradients (G0) and transverse relaxation times in liquid-saturated packings of glass beads of different wettabilities. We show how these correlations can be expressed as two-dimensional (2D) diagrams of distribution functions between internal magnetic field gradients and T2 values. In the case where it is difficult to distinguish the signals from oil and water, we separate them based on their difference in diffusivity.