Subsurface Migration of Gas and Fluids

NETL efforts focus on better knowledge of how fluids and gas can migrate in complex geologic systems due to energy resource development.

Leads to improved ability to predict fluid and gas migration into shallow systems:

  • Natural and synthetic chemical tracers to track gas and fluids in geologic systems
  • Understanding distribution and integrity of wellbores using field-based and existing data 
  • Evaluating the effects of shallow stray gas on well cement integrity
  • Integrated modeling to predict naturally-occurring versus development-induced fluid and gas migration

Need for reliable tracers to track the sources of geologic fluids, that can be analyzed reliably, quickly and at low cost

Solution: NETL is developing rapid sample processing and analytical chemistry tools for natural geochemical tracers that can be used to identify the sources of fluids and gases in complex geologic systems undergoing energy development

Existing wellbores may serve as conduits for fluid and gas migration from depth to shallow systems

NETL is performing field magnetic surveys coupled with ground-truthing, and data mining of existing wellbore locations, to develop tools for evaluating the densities and locations of potential leakage pathways  

Shallow gas may affect the physical integrity of cements as new wells are being developed in natural gas-rich geologic systems

NETL isperforming laboratory work to investigate the effect of gas on the effectiveness of well cements, and is mining existing data
resources on causes for poor well cementing in gas-rich systems

Observation of methane in shallow reservoirs has been attributed both to natural processes and shale-gas related activities, with limited knowledge on which is the dominant process.

NETL is developing tools to evaluate the distribution of methane in the Appalachian Basin, and is developing means to evaluate how different shale gas extraction processes affect the natural distribution of methane due to changes in hydrology.
Using Natural Geochemical Tracers to Track Fluid Migration
Chapman, E.; Capo, R.; Stewart, B.; Kirby, C.; Hammack, R.; Schroeder, K.; Edenborn, H. M. "Geochemical and strontium isotope characterization of produced waters from Marcellus Shale natural gas extraction." Environ. Sci. Technol. 46: 3545-3553

Airborne Magnetic Well Survey Results