Impact of Micro-to Meso-scale Fractures on Sealing Behavior of Argillaceous Cap Rocks For CO2 Sequestration

Evans, James¹ 

[1] Utah State Univ., Logan, UT (United States)

关键词: CO2;    seal;    integrity;    bypass;    storage;   

DOI  :  10.2172/1302338
RP-ID  :  USU-DOE--0004991-1
PID  :  OSTI ID: 1302338

学科分类：地球科学(综合)

美国|英语

来源: SciTech Connect

【 摘 要 】

This multi-disciplinary project evaluated seal lithologies for the safety and security of long-term geosequestration of CO₂. We used integrated studies to provide qualitative risk for potential seal failure; we integrated data sets from outcrop, core, geochemical analysis, rock failure properties from mechanical testing, geophysical wireline log analysis, and geomechanical modeling to understand the effects of lithologic heterogeneity and changing mechanical properties have on the mechanical properties of the seal. The objectives of this study were to characterize cap rock seals using natural field analogs, available drillhole logging data and whole-rock core, geochemical and isotopic analyses. Rock deformation experiments were carried out on collected samples to develop better models of risk estimation for potential cap rock seal failure. We also sampled variably faulted and fractured cap rocks to examine the impacts of mineralization and/or alteration on the mechanical properties. We compared CO₂ reacted systems to non-CO₂ reacted seal rock types to determine response of each to increased pore fluid pressures and potential for the creation of unintentional hydrofractures at depth.