Saudi Aramco Unveils New LWD NMR Technology for Field Operations

The Saudi Aramco EXPEC Advanced Research Center has successfully developed and tested the industry's first small-hole Logging-While-Drilling Nuclear Magnetic Resonance tool (LWD NMR).

Two years ago, EXPEC ARC teamed up with Baker Hughes and the Reservoir Description and Simulation Department to develop the next-generation NMR technology useful for obtaining real-time measurements in angled and horizontal wells of small diameters. That effort has now succeeded in the development of a tool deployed while drilling that provides this sought-after capability, and the first two prototypes have been deployed in Saudi Aramco fields.

"EXPEC ARC identified a clear business need, built the team and succeeded with a most innovative, valuable tool that will contribute significantly in placing wells in the most productive zones of our reservoirs," said Abdulla A. Al Naim, vice president of Petroleum Engineering and Development.

Nuclear magnetic resonance (NMR) is a technique that exploits the magnetic properties of nuclei of certain atoms, such as hydrogen, that contain odd numbers of protons or neutrons. When a magnetic field is applied, the result is NMR spectroscopy and magnetic resonance imaging. A familiar use of NMR spectrum is in magnetic resonance imaging (MRI) for medical diagnosis.

The oil industry adapted the MRI technique to probe and diagnose how much hydrogen exists within the rock space some thousands of feet below the ground. The NMR technique reveals rock-pore characteristics and how much hydrocarbon and water are contained within the rock.

This LWD NMR tool, at only 12 centimeters in diameter and the first of its type, has been proven in field applications. It was run in combination with other LWD tools in a 1,524-meter section of Arab reservoir, accurately measuring reservoir properties such as porosity. A second test of the tool was conducted in a well of a different field with similarly successful results.

"This tool is critical to our field development. It will provide us with real-time estimates of the presence of tar and therefore guide our geosteering capabilities in many of our fields," said Muhammad M. Saggaf, manager of EXPEC ARC. "Now, we can be more successful in avoiding the troublesome tar zones and in complementing our rock and reservoir analysis."

NMR logging has improved continuously over the past two decades. The exploration and producing industry uses NMR measurements for a host of applications, including better understanding of pore geometry, improving the design of hydraulic fracturing treatments, formation evaluation, optimizing management of the assets and supporting real-time geosteering activities.

LWD is the most effective way to evaluate the reservoir from real-time downhole measurements acquired by tools deployed within the drilling string. Different LWD tools acquire different logging measurements, which together provide an integrated assessment of reservoir characteristics, hydrocarbon abundance, fluid properties, etc., then send that information through pulses in the drilling "mud" from the tool to the wellhead and then, via satellite, to Dhahran.Now, for the first time in the industry, EXPEC ARC has combined both of these capabilities in establishing an effective solution for slim hole applications.