We propose that the Play-Based methodology for characterizing the exploration potential of an area developed and successfully used in Petroleum exploration during the last two decades should 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.
Because both the application for an injection project permit is iterative, and because the development of a carbon sequestration project is a long-term, capital-intensive, multi-stage process, we further propose that the “Stage-Gate” process developed for the management of capital-intensive E&P projects should be utilized to properly manage these endeavors.
Under the EPA guidelines, the first US application for a Class 6 reinjection project permit took six years to get approved. Recently, most Class 6 well permit approvals take about two years. The application of structured E&P exploration and project management processes provides opportunities to both reduce the cycle time of these projects, and improve the quality of the subsurface characterization.
The characterization of plays at a regional and sub-regional scale, illustrated on Common Critical Risk Segment (CCRS) maps can be applied to demonstrate the risks and uncertainties for a CCUS project. In these projects, the critical subsurface factors are Capacity, Injectivity, and Containment, which in terms of assessing risks and uncertainties, are directly analogous to the Petroleum Play elements of Reservoir Presence, Reservoir Quality, and Seal Presence and Capacity. It is arguable that the element of Charge should also be considered, as ideally in a Greenfield project we do not wish to be drilling into an unpredicted hydrocarbon column.
The methodology defines the risks and manages the uncertainties in reservoir (storage container) characterization that rise from our imperfect knowledge of the subsurface parameters used to define developable volumes of hydrocarbons in place. The critical elements used to characterize a hydrocarbon accumulation are: Charge, Reservoir, Trap and Seal. Geologic, seismic, and potential fields data are used to reduce the uncertainty in the ranges of the parameters used in the petroleum or carbon storage container characterization.
The use of the Play-Based exploration methodology reduces subsurface uncertainty in the permit application process by providing a consistent approach to data quality and reliability assessment and statistically valid data analysis leading to 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, thee elements assessed in 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 for these critical elements then define “sweet spots” for injection wells.
The iterative nature of the Class 6 well application process lends itself well to the Major Project “Stage-Gate” division of a project into Initiate (Pre-Application), Assess (Pre-Injection), Define (Pre-Construction), Execute (Injection) and Operate (Post-Injection) elements.
On a larger scale, this Capital Projects management methodology can also be applied to the full-cycle of a major Greenfield sequestration project, where the separate elements of Collection and Transportation (from industrial sources), Storage and Injection (storage, geological characterization, drilling, and injection at the project site), and Conformance Monitoring (well observation and 4D seismic)should all be managed under this process.
This is a summary of the Poster to be presented at AAPG CCUS, HOUSTON, TEXAS, MARCH 29-31 2022. Come at see us at 12:00-1:45 pm on March 31st at Hilton hotel, University of Houston
