The EPA application process for the injection project permit is an iterative process, requiring the completion of an extensive questionnaire that covers a detailed description of the subsurface, addressing regional and local aspects of the storage container. We propose that the Play-based assessment methodology developed and successfully used in Petroleum exploration during the last two decades could be deployed for the characterization of the risks and uncertainties of the Area of Review (AoR) as defined by Environmental Protection Agency (EPA) for Class 6 well (CCUS) permit approval process.
The first application for this permit took six years to get approved, largely because of “recycling” as the requirements were properly understood. Recently, data show that Class 6well permit approvals now take about two years. The utilization of play-basedassessment methods offers opportunities to further reduce the cycle time of the application and improve the quality of the subsurface characterization.
The Common Critical Risk Segment methodology used in play-based assessment defines the risks and manages the uncertainties in the critical elements used to characterize a hydrocarbon accumulation (Source, Reservoir, and Seal). Well, seismic, and potential fields data are used to reduce the uncertainty in the ranges of the parameters used in the characterization. The same data sources and methodology can be applied to understanding the range in critical parameters required for developing an appropriate injection site…the absence of petroleum fluids, the presence of saline aquifer with sufficient porosity and permeability, and an overlying seal of known capacity.
Reducing uncertainty in subsurface characterization in the permit application process is possible utilizing the consistent approach to data quality and reliability assessment and statistically valid data analysis embedded within petroleum business processes that were developed to deliver a better understanding of the subsurface variability.
Using the language of the Petroleum industry and translating it into the critical elements for carbon storage characterization we can say that elements assessed in the CCUS permit application process are:
- Petroleum Reservoir = CCUS Container quality
- Storage (bulk volume, porosity, saturation).
- Injectivity (geometry, permeability, relative permeability)
- Petroleum Trap = CCUS container definition
- Geometry confining elements
- Petroleum Seal = CCUS upper AND lower seals
- Max seal capacity for injected volumes (capillary entry, fractures, faulting)
CCRS maps maybe used to define a sweet spot for injection well positioning determined by the configuration of the most favorable parameters of each critical element.
This paper will be presented in ICE AAPG Cartagena 2022, Colombia .
