Geological & Environmental Systems

Geological and Environmental Sciences (GES) is a focus area of the National Energy Technology Laboratory’s Research & Innovation Center (RIC). RIC’s other focus areas are Energy System Dynamics, Computational and Basic Sciences, and Materials Science and Engineering. Scientists and engineers in the Research and Innovation Center conduct research at NETL’s advanced research facilities in Albany, OR; Morgantown, WV; Pittsburgh, PA, and at various offsite locations.

GES tackles the challenge of clean energy production from fossil energy sources by focusing on the behavior of natural systems at both the earth’s surface and subsurface, including prediction, control, and monitoring of fluid flow in porous and fractured media. Efforts include the long-term storage of CO₂, the environmentally sound production of our nation’s conventional and unconventional fossil fuel resources, and the science base needed to bring methane hydrates into the domestic natural gas resource base.

Core Competencies

To accomplish our mission, GES has five core competencies that underpin most of our work.

• Multiscale, multiphase flow; including an in-house DFN reservoir simulator NFFLOW
• Strategic monitoring of natural-system behavior.
• Geomaterials science (both geophysical and geochemical aspects of earth materials).
• Geospatial data management and assessment.
• Drilling under extreme conditions.

Capabilities

We conduct integrated laboratory and field experiments and computer simulations to improve our understanding of sequestration options and to identify and address potential challenges. We use the geophysical and geochemical capabilities of the GES to achieve the goal of secure CO₂ storage. We have the capability to:

• Locate abandoned oil wells using airborne and ground-based magnetometry.
• Evaluate leakage potential through the use of radiometry and methanometry.
• Perform vertical seismic profile studies.
• Monitor surface and ground water aquifer chemistry changes, fluxes of CO₂ at the surface, and natural (e.g., radon and light hydrocarbons) and artificial tracers in soil-gas.
• Evaluate the integrity of well-sealing cements under down-hole temperature and pressure conditions.

GES’s modeling capabilities include predicting flows in CO₂ stored underground; these predictions can be then validated by collaboration with laboratory and field experiments. The same models are also being used to simulate unconventional and enhanced oil recovery. GES scientists and engineers are also exploring methane hydrate deposits, which are believed to contain more energy-producing organic carbon than all of the world's conventional fossil fuels combined. We are conducting research on how these hydrate deposits can become part of our domestic gas reserves. We also study the potential role that hydrates play in climate change and the carbon cycle, and the impact that hydrates have on seafloor stability and deep-sea life.

Key Facilities

• Geomechanics and Flow Laboratory: Measures the permeability, stress and strain relationship, and Poisson’s ratio of core samples under sequestration conditions. Long-term, high-pressure static experiments simulating sequestration conditions are also conducted in this laboratory.
• CT Scanner Facilities: Provides 3D imaging data at a variety of physical scales. Includes a medical CT scanner, an industrial grade CT scanner, and a micro-CT scanner.
• Shallow Well Laboratory: Simulates 4,000-ft depths with its 8 static, stainless steel 2 L autoclaves with an operations envelope up to 50 °C at 1,500 psig.
• Deep Well Laboratory: Simulates 8,000-ft depths using 6 stirred and static stainless steel 1.2 L autoclaves operating up to 200 °C at 4,500 psig, and a stirred and static Hastalloy C 2 L autoclave with an operations envelope up to 350 °C at 5,000 psig.
• Advanced Drilling Research Laboratory: Features a new ultra-deep drilling simulator that can test drilling equipment and drilling-mud formulations at pressures up to 30,000 pounds of force per square inch and temperatures exceeding 480 °F.
• Brine Sequestration: Features a hydrothermal rocking autoclave test unit for temperatures up to 300 °C and pressures up to 600 bar. Includes autoclaves with half-liter and one-liter continuously stirred reactors for gas-liquid or gas-slurry interactions, a phase behavior lab with 30–40 cm3 high-pressure, variable-volume cells with viewing windows, and smaller, stirred autoclaves.
• High-pressure Water Tunnel Facility: Allows observation of the chemical, physical, and hydrodynamic behavior of solids, drops, and bubbles stabilized solely by a countercurrent flow of liquid at conditions from near-freezing to 90 °C, and up to 5,000 psig.
• Infrared Spectroscopy Test Facility: Examines direct interaction between CO₂ and coal or solid compounds over time, and under different pressures and temperature conditions.
• Manometric Sorption Test Facility: Characterizes the sorption capacity of coals. Adsorption isotherms can be measured on coal powders and solid core samples from ambient to 750 °F.
• Separations Laboratory: Examines methods for removing CO₂ and trace contaminants present in coal-derived gas streams such as flue or fuel gases. 
• Mobile Air Monitoring Laboratory: Measures particulate matter, volatile organic compounds, oxides of nitrogen, sulfur dioxide, ozone, ammonia, ions (such as sulfate and nitrate), organic and elemental carbon, visibility, and meteorological variables at field sites.
• Analysis Instrumentation: Includes ICP-OES, ICP-MS, high-pressure liquid chromatography, cold vapor atomic fluorescence, and thermal gravimetric analysis.

Recent Achievements

• Rediscovery of abandoned wells in the world's first oil field, Historical review and evaluation of methods to map and measure methane emissions from abandoned wells.
• SEQURE™, a patented tracer technology, uses non-toxic, chemically inert perfluorocarbon tracers to provide a verifiable way to fingerprint stored CO₂, thereby giving an early indicator if CO₂ is released from a storage reservoir. SEQURE received R&D Magazine’s prestigious R&D 100 Award in 2009.
• A new ultra-deep drilling simulator is being developed to understand drilling dynamics, including rate of penetration and materials performance, at pressures up to 30,000 pounds of force per square inch and temperatures exceeding 480 °F, which is up to three times greater than the pressure and temperature ranges of other simulators.
• Innovative mathematical methods that simulate fluid flow in porous and fractured reservoirs give researchers the ability to predict the capacities of coal seams and saline formations to receive CO₂. NETL’s model was validated when it produced results that agreed well with field data obtained from the Allison field in northwest New Mexico, the world’s first enhanced coalbed methane-carbon sequestration field project.
• GES researchers are determining how flow channels in well-bore cements and other seal-related materials respond in the presence of pressurized brine and CO₂. During geological storage, CO₂ and brine will interact chemically with seal materials as they flow through fractures or channels. Depending on the conditions, flow paths can be enlarged through dissolution or sealed with new minerals that are deposited. The ability to predict the evolution of these flow paths is a key aspect of ensuring the integrity of a storage reservoir. GES experiments exploring channel-flow in wellbore cement indicate that small channels close, at least at low flow velocities. This also suggests that small fractures in some seal materials may not increase the risk of CO₂ release.
• Hybrids of clays and iron oxide nanoparticles developed by GES scientists could serve as important rheological additives in drilling fluids. The hybrids possess unique magnetic properties unattainable in individual clay or iron oxide particles. Addition of the nanoparticles allows the rheology of water- or oil-based fluids to be finely tuned using an external magnetic field.  The innovation could not only increase the efficiency of drilling operations and the longevity of drilling tools but could also find a wide range of applications in mechanical, electronic, and biomedical systems.
• GES researchers have determined a correlation between acoustic wave velocity and relative CO₂ saturation that can be used to calibrate and refine the interpretation of 3D seismic reflection surveys. This new procedure could be used to more effectively track the movements of CO₂ after injection for carbon storage or enhanced oil recovery.
• Geotechnical data obtained from sediment cores retrieved during a recent expedition into the U.S. Beaufort Sea show that the shallow sediments in this area off Alaska’s North Slope are very consolidated, which has implications for the detection and assessment of subsurface permafrost and hydrate occurrences. GES scientists and our collaborators are using the data to better define the areas of methane flux from the subsurface, which is important in modeling global climate change.
• The Orphan Wells Locations Survey was created to locate and log coordinates of abandoned oil and gas wells, which will be further studied in methane emissions research projects; maps of data collected from the survey will be periodically published to the community.

This research supports NETL’s Geological & Environmental Systems competency.