Liability Issues Related to Geological Storage of CO 2

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1 Liability Issues Related to Geological Storage of CO 2 Sally M. Benson Earth Sciences Division Lawrence Berkeley National Laboratory Berkeley, California smbenson@lbl.gov

2 Carbon Dioxide Capture and Storage is Needed to Reduce Emissions From Fossil Fuels

3 Options for Geological Storage From IPCC Special IPCC, Report 2005

4 Carbon Dioxide Capture and Storage is a Growing CO 2 Mitigation Option SaskPower From Peter Cook, CO2CRC, Australia

5 What Do We Know About the Risks of Geological Storage of CO 2? With appropriate site selection informed by available subsurface information, a monitoring program to detect problems, a regulatory system, and the appropriate use of remediation methods to stop or control CO 2 releases if they arise, the local health, safety and environment risks of geological storage would be comparable to risks of current activities such as natural gas storage, EOR, and deep underground disposal of acid gas.

6 Storage Formation Specific Risks Depleted Oil Fields Natural Gas Storage in Depleted Oil Fields Depleted Gas Fields Natural Gas Storage in Depleted Gas Fields CO 2 EOR with Storage CO 2 EOR Saline Formations Natural Gas Storage in Saline Formations Enhanced Coal Bed Methane Coal Bed Methane Recovery

7 TRC Rate for Various Oil and Gas Related Activities 20 10,00<employees <=31,600 31,600<employees <=100, ,000<employees <=316, ,200<employees <=1,000, TRC/200,000 hours/year % 50% 25% Geophysical Surveying and Mapping Services* Pipeline transportation of natural gas Drilling oil and gas wells Pipeline transportation Site preparation contractors Support activities for oil and gas operations* Oil and gas extraction Utility system construction *denotes industry class for which only 2004 rate available. Total Recordable Case (TRC) rate box plots for NAICS industry classes within an employment size group. Size groups shown are in thousands of employees. TRC rates for industry classes participating in the oil and gas exploration and production industry are shown.

8 DA Case Rate for Various Oil and Gas Related Activities 7 10,00<employees <=31,600 31,600<employees <=100, ,000<employees <=316, ,200<employees <=1,000, DA/200,000 hours/year % 50% 25% Geophysical Surveying and Mapping Services* Pipeline transportation of natural gas Drilling oil and gas wells Pipeline transportation Site preparation contractors Support activities for oil and gas operations Oil and gas extraction Utility system construction Days Away case (DA) rate box plots for NAICS industry classes within an employment size group. Size groups shown are in thousands of employees. DA rates for industry classes participating in the oil and gas exploration and production industry are shown.

9 Estimated Fatality Rates* Oil and Gas * Preliminary assessment, subject to change

10 What Does a Good Storage Project Look Like? Three examples Sleipner, off-shore Norway Weyburn, Canada In Salah, Algeria CO 2 remains in the storage reservoir Formation pressures remain below the fracture gradient Wellbore integrity is maintained Monitoring demonstrates satisfactory performance No serious accidents From Chadwich et al, 2004 Seismic data at Sleipner demonstrate CO 2 containment

11 What Could Go Wrong? Potential failure pathways for a poorly conceived and executed storage project Well leakage (injection and abandoned) Poor site characterization (undetected faults) Excessive pressure buildup damages seal Potential Consequences 1. Worker safety Industrial operations accidents CO 2 exposure due to leakage from surface and subsurface facilities 2. Financial losses Emissions to atmosphere Pre-mature closure Litigation expenses 3. Groundwater quality degradation CO 2 and geochemical reaction products Brine or gas displacement, including dissolved or separate phase hydrocarbons 4. Resource damage Migration to oil and gas fields Migration to minable coal 5. Ecosystem degradation Terrestrial plants and animals Aquatic plants and animals 6. Public safety CO 2 exposure due to leakage from surface and subsurface facilities 7. Structural damage Induced seismicity Differential land surface subsidence or inflation

12 How Can These Problems Be Avoided? Regulatory Oversight Remediation Plans Monitoring Safe Operations Storage Engineering Effective Site Selection and Characterization Methods Fundamental Scientific Knowledge of Storage and Leakage Mechanisms

13 CO2 is Contained in Tiny Pore Spaces 2-D image of CO2 in pore space Water Rock CO2 2 mm Microtomography at the Advanced Light Source 2-D pore space image 3-D pore space image 3-D image of CO2 in pore space

14 Site Characterization and Selection Are of Paramount Importance Saline Formations Faults or gaps in seal Fracture gradient Wells Oil and Gas Reservoirs Abandoned wells Fracture gradient Modified from J. Freidman, 2006

15 In North America Abandoned Wells Are A Significant Issue From IHS Energy Well density and risks from abandoned wells depends on location

16 Longer Term Issues: Post Injection Storage security increases over time Secondary trapping mechanisms Pressure decline Time frames are site specific Projects can be engineered to enhance trapping Monitoring can demonstrate longer term performance Eventually, a high degree of assurance will be achieved

17 Conceptual Risk Profile Injection begins Injection stops 2 x injection period 3 x injection period n x injection period Monitor Model Calibrate Model Validate Model Calibrate Post Injection Model Validate Post Injection Model

18 More Experience With Large Commercial Scale Projects is Needed Acid gas injection Sequestration projects CO 2 Plume ~ 10 2 km 2 Tonnes/day of CO 2 injected EOR West Coast (Jedney, USA) 500 MW coal plant UT (Frio Brine) Statoil (Snohvit) BP (In Salah) Chevron (Rangeley) Kinder Morgan (Sacroc) Chevron (Acheson, 1 st AGI site, 1989) West Coast (Largest AGI site, 2002) Battelle (Saline Experiment) Statoil (Sleipner) EnCana (Weyburn) Amerada Hess (Seminole) Altura (Wasson) Operator (field) From IPCC, 2005