Depositional Environment as an Indicator of Favorable Regional Sequestration Targets: Examples from the USGS CO2 Storage Resource Assessment

摘要

An analysis of the of sealing formations chosen as cap rocks in the U.S. Geological Survey (USGS) geologic carbon dioxide (CO2) storage resource assessment reveals certain depositional environments that produce suitable regional scale sequestration seals. The USGS methodology requires low permeability, regional, and homogenous seals of approximately 30 meters thickness for shales and 6 meters thickness for evaporites. Open-shelf marine slope and basin shales, as well as shallow water evaporitic deposits make up a majority of storage formation seals identified in the assessment that meet this criteria. Since adequate cap rock is the limiting component of the reservoir and seal couplet required to sequester CO2, these specific depositional environments are recommended as initial targets for regional-scale sequestration assessments and research.