Researchers at the Energy Department's National Energy Technology Laboratory (NETL) are using a laser-based technology to create methods that can better quantify certain environmental impacts associated with fossil energy production or underground carbon storage by assessing gases, water, and soil quality underground.

Researchers adapted Laser Induced Breakdown Spectroscopy (LIBS) hardware to well-bore monitoring applications. They say the work makes LIBS more effective and easier to use for in-the-field subsurface research.

Much of what the researchers hope to monitor is underground. They say that most traditional monitoring technologies cannot function in the subsurface environment where conditions are different than at the surface. Existing monitoring techniques can be expensive and labor intensive, often requiring complicated sample collection and preparation that can alter a sample and its parts.

To determine what elements are present, the NETL LIBS 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 an optical fiber to the surface. There, a spectrometer analyzes the light for evidence of elemental composition.

Oil and gas exploration companies, landowners, regulatory agencies and municipalities, among others are interested in a simpler and more cost-effective approach that can be deployed on-site and survive long-term in downhole conditions.

LIBS can be applied to in-situ measurements of gases, liquids, and solids, making it amenable to monitoring air, water and soil. NETL, with an innovative approach, has designed a simple, easy-to-fabricate, handheld LIBS sensor for field use that is capable of measurements in subsurface environments.

NETL says that its LIBS sensor has the potential to make monitoring for leaks more accurate and affordable in the future.

Future NETL work based on the LIBS monitoring tool will further leverage partnerships with industry to commercialize the technology.