NETL researchers are using a laser-based technology to create newer methods that can better quantify certain environmental impacts associated with fossil energy production or underground carbon storage by assessing gases, water and soil quality in situ underground.

Specifically, the experts at NETL have adapted Laser Induced Breakdown Spectroscopy (LIBS) hardware to well-bore monitoring applications, making LIBS more effective and easier to use for in-the-field subsurface research.

Much of what these researchers hope to monitor is underground, but most traditional monitoring technologies cannot function in the subsurface environment, where conditions, such as brine emersion and pressure, are much different than at the surface. Monitoring techniques that do exist are expensive and labor intensive, often requiring complicated sample collection and preparation that can alter the sample and its constituents.

Oil and gas exploration companies, land owners, regulatory agencies, municipalities and many others are keenly interested in a simpler and more cost-effective solution – one that can be deployed on-site and survive long-term in downhole conditions.
That’s where LIBS technology comes into the picture, especially as adapted by NETL. LIBS is a type of atomic emission spectroscopy that offers solutions to the challenges of conventional environmental monitoring techniques by providing rapid and relatively simple qualitative and quantitative elemental analysis - all without the need for extensive sample collection or preparation.

Moreover, LIBS can be applied to in-situ measurements of gases, liquids and solids, making it amenable to the monitoring of air, water and soil. However, many of the available LIBS systems are large and complex, employing above-ground, laboratory-scale lasers. NETL, with an innovative approach, has designed a simple, easy-to-fabricate, handheld LIBS sensor fully adaptable to field use and capable of measurements even in subsurface environments.

Knowing what elements are present in a subsurface sample can be valuable. For instance, monitoring is an important aspect of carbon storage applications because stakeholders need assurances that carbon dioxide will remain permanently stored in geologic formations. NETL’s LIBS sensor has the potential to make monitoring for leaks more accurate and more affordable in the future, while also opening the door to many other applications like downhole measurements for the oil and gas industry.

“Here’s how it basically works,” Dustin McIntyre, who has worked to advance LIBS monitoring technologies at NETL, explained. “To determine what elements are present, the device creates a pulse of light that is amplified and focused to make a spark in the water or substance being measured. The spark emits light in all directions, creating characteristic atomic emissions. This light is then back-transmitted through the device, traveling up the optical fiber to the surface. Topside, a spectrometer analyzes the light for evidence of elemental composition.”

Future NETL work based on the LIBS monitoring tool will further leverage partnerships with industry to commercialize the technology. McIntyre and his team are also expanding their research to include a new LIBS flow lab, in which they will be able to further refine their sensor’s design by replicating the downhole environment in the lab.

Creating new monitoring systems that yield quick and effective information, even under harsh conditions in the field, is one way NETL researchers are building upon the Laboratory’s mission to discover and mature technology solutions that enhance the nation’s energy foundation and protect the environment for future generations.

Contact:

• Shelley Martin, DOE National Energy Technology Laboratory, 304-285-0228, contact.publicaffairs@netl.doe.gov