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Title: Prototype Near-Field/GIS Model for Sequestered-CO2 Risk Characterization and Management

Conference ·
OSTI ID:883553

Detecting unmapped abandoned wells thus remains a major carbon sequestration (CS) technology gap. Many (>10{sup 5}) abandoned wells are thought to lie in potential sequestration sites. For such wells, risk analysis to date has focused on aggregate long-term future impacts of seepage at rates < or << {approx}1 g m{sup 2} d{sup -1} on storage goals as sequestered plumes encroach upon wells with assumed distributions of seal ineffectiveness (Oldenburg and Unger, 2003; Saripali et al. 2003; Celia, 2005). However, unmapped abandoned wells include an unknown number without any effective seal at all, venting through which may dominate CO{sub 2}-loss scenarios. A model of such a well is Crystal Geyser (CG), a prospective oil well abandoned in the 1930s with no barrier installed after it encountered a natural CO{sub 2} reservoir rather than oil (Baer and Rigby, 1978; Rinehart, 1980). CG demonstrates how an unimpeded conduit to the surface now regularly vents from 10{sup 3} to >10{sup 4} kg of CO{sub 2} gas to the terrestrial surface (Figure 1). Unique field data recently gathered from Crystal Geyser (CG) in Utah (Gouveia et al. 2005) confirm that, although resulting surface CO{sub 2} concentrations resulting from CG-like eruptions would likely be safe in general, they could accumulate to pose lethal hazards under relatively rare meteorological and topographic (MT) conditions. This source of foreseeable risk needs to be managed if carbon sequestration is to be publicly accepted. To address this concern, we used CG field data to estimate the source term for a prototype model that identifies zones at relatively highly elevated risk for sequestered-CO{sub 2} casualties. Such a model could be applied both to design and comply with future regulatory requirements to survey high-risk zones in each proposed sequestration site for improperly sealed wells.

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
883553
Report Number(s):
UCRL-CONF-218918; TRN: US200615%%123
Resource Relation:
Conference: Presented at: International Symposium on Site Characterization for CO2 Geological Storage, Berkeley, CA, United States, Mar 20 - Mar 22, 2006
Country of Publication:
United States
Language:
English