Geological Sequestra0on of CO2 and Leakage through Faults PECS Student Dinner Presenta0on Mary Kang Civil and Environmental Engineering Advisor: Michael Celia January 23, 2012
Outline • Carbon Capture and Storage – Why CCS? – CCS issues – Geological storage of CO2 – Modeling CO2 injec0on/migra0on/leakage – Faults and CO2 storage • My research – Combined analy0cal-‐numerical mul0-‐scale modeling of two-‐phase ﬂow in basins containing faults
Why CCS? • To combat climate change, need to implement a porTolio of strategies – Given our current dependence on fossil fuels, CCS at a large scale is a necessary bridge solu0on IEA, 2011
Carbon Capture and Storage (CCS) Issues • Commercially-‐viable? At what scale? • Economics: Cost, Free-‐trade, Taxes… • Societal acceptance • Developed vs. developing countries … How can CCS be made part of a commercially-‐viable, integrated sustainable and secure energy system? Should CCS be mandatory in the developed world? Is the general public informed enough to make decisions on climate change? …
Should CCS be mandatory in the developed world?
Survey at IEAGHG CCS Summer School Should CCS be mandatory in the developed world? 64%YES 36% NO *Based on a survey of 72 IEAGHG CCS Summer School par0cipants.
Survey Results by Beverage Preferences 74%YES 50%YES 65%YES26% NO 50% NO 35% NO*Based on a survey of 72 IEAGHG CCS Summer School participants.
Survey Results by Na0onality DEVELOPED DEVELOPING 54%YES 80%YES 46% NO 20% NO*Based on a survey of 72 IEAGHG CCS Summer School participants.
Is the general public informed enough to make decisions on climate change?
ZEP, 2010 What do I know? What do I care? Polls Percep(ons and beliefs 42% believe in climate change, down from 62% in 2006 Der Spiegel (2010) 26% believe climate change is happening & largely man-made, down from 41% in 2009 BBC (2010) 11
Geological Storage of CO2 • Op0ons are: – Unmineable coal seams – Depleted oil and gas reservoirs – Saline aquifers IPCC, 2005
Prac0cal Ques0ons for CO2 Storage in Saline Aquifers 1. What is the spa0al extent of the CO2 plume, and the extent of the pressure perturba0ons, as a func0on of 0me, during and aher the injec0on period? 2. What frac0on of the injected CO2 and displaced brine will leak out of the injec0on forma0on? And where will the leaked ﬂuid(s) go? 3. What is the overall long-‐term fate of the injected CO2?
The Leakage Problem • To implement CCS at a large scale using geological storage of CO2, – Need to quan0fy risk of leakage through Fault concentrated pathways Upward Flow (i.e. abandoned wells and faults) in basins Gasda et al., 2004
Modeling CO2 and Brine in Geologic Forma0ons Geologic forma@ons are layered. Combined analy0cal-‐numerical mul0-‐scale modeling
Modeling CO2 and Brine in Geologic Forma0ons Basin-‐scale ﬂow and leakage dynamics should be modeled at diﬀerent scales. Coarse-‐Scale Numerical Model 1" … n" n" 1" Fine-‐Scale Analy0cal Models Combined analy0cal-‐numerical mul0-‐scale modeling 16
Faults • Deﬁni0on: A fault is a planar feature or discon0nuity in a volume of rock, across which there has been signiﬁcant displacement as a result of earth movement. hjp://en.wikipedia.org/wiki/File:Faille_des_Causses_depuis_Bedarieux.dsc02071.cr 17 opped.jpg
Role of Faults • Need for a tool to evaluate poten0al for CO2 leakage through fault • Considera0ons for development Faulkner et al., 2010 – Uncertain0es in fault proper0es – Mul0-‐scale aspect of the problem Area 170,000 km2 (65,000 mi2) Flodin et al., 2001 hjp://news.medill.northwestern.edu/chicago/news.aspx?id=155598
My Research Objec0ve • Develop a computa0onal tool that can evaluate poten0al for CO2 leakage through faults for use in basin-‐scale models
My Research Ques0ons 1. How can faults be conceptualized to represent the ﬂow ﬁeld around the fault? 2. How can the model(s) developed to answer Ques0on 1 be integrated into a large-‐scale numerical model? 3. What are the barriers to applica0on of the model to real problems (i.e. in CCS)? And how can they be addressed?
Fault Conceptualiza0on: 1-‐D Upconing for Highly Conduc0ve Faults Allowing ver0cal non-‐equilibrium, y houter fault x houter vertical equilibrium 21
A Way to Represent Faults in Basin-‐Scale Models Coarse-‐Scale Numerical Model 1" … n" n" 1" Fine-‐Scale Analy0cal Models Combined analy0cal-‐numerical mul0-‐scale modeling 23
A Fine-‐Scale Model • Reconstruc0on ¯ ¯ hp h0 hf ault pf ault – p → pf ault ¯ Top – h → h0 ¯ View • Flow to fault Solve Eqns – 1D upconing solu0on Simultaneously • Flow through fault – 1D two-‐phase Darcy ﬂow cap cap 24
Reconstruc0on • Take the coarse-‐scale solu0on and reconstruct some approxima0on of the ﬁne-‐scale solu0on for a given 0me step. R Coarse-‐Scale p ¯ ¯ p(x, z) Reconstructed ˆ SBlock Average Qα α Fine-‐Scale ˆ h(x) Model C Compression 25
Summary • CCS – Given our current dependence on fossil fuels, must deploy CCS at large scale – Technical, social, economical barriers – CO2 storage poten0al in saline aquifers is large – Models designed to quan0fy risks associated with leakage are needed • Leakage through faults – A combined analy0cal-‐numerical mul0-‐scale model given highly conduc0ve faults ac0ng as leakage conduits in