The discovery of Nuclear Magnetic Resonance (NMR) phenomenon spawned innovative diagnostic
technologies that facilitated advancements in a wide range of disciplines including medicine, chemistry
and earth sciences. Geologists observed that in a manner similar to Magnetic Resonance Imaging (MRI)
that revolutionized medical imaging, NMR measurements illuminate pore-filling fluids inside a porous
rock and provide unique insight to porosity, pore size and/or fluid viscosity without any damage to the
For the oil and gas industry, this sensor technology has become everyday reality with the development
of NMR well-logging tools. Since the first modern NMR logs in the early 1990s, NMR logging enhanced
formation evaluation in complex reservoir rocks such as heterogeneous carbonates and silty sands and
enabled reservoir fluid characterization in the presence of fresh water, heavy oil or variable gas-oil ratio.
More recently, with the development of logging-while-drilling (LWD) tools, NMR petrophysics is
available for real-time reservoir navigation.
With these advancements, upstream operators can realize significant value in their exploration,
evaluation and field development activities. First, the cost and time savings by optimizing formation
testing, sampling and well testing operations thanks to the more accurate reservoir quality and fluid
mobility evaluation significantly outweigh measurement costs in most cases. Second, NMR logs uncover
hidden reservoirs with low resistivity contrast in the presence of laminar shales or carbonate
microporosity. Finally, NMR-driven placement of injector and producer wells reduces field development
costs and potentially increases hydrocarbon recovery.
This lecture shares the lessons of two decades of learning by an experienced operator with field
examples that show how to increase operational efficiency and improve reservoir understanding with
wireline and LWD NMR logging technology. Participants are encouraged to bring their own logs for
customized review and discussion.
Gabor Hursan is Saudi Aramco’s lead subject matter expert in NMR logging, working at the Reservoir
Description & Simulation Department. He oversees the company’s NMR oilfield operations, data
analytics and petrophysical interpretation procedures, conducts formation evaluation studies for
exploration and reservoir development projects. Prior to joining Saudi Aramco in 2011, he worked as a
scientist at Baker Hughes in various positions for 10 years on downhole NMR instrumentation and data
processing software development. He has MS and PhD degrees, both in Geophysics. He published over
40 papers and patents, teaches in-house and external courses in NMR logging. He serves SPE and SPWLA
as reviewer for technical publications, and is a founding member of SPWLA’s NMR Special Interest