Reactive transport of CO2-saturated water in a cement fracture: Application to wellbore leakage during geologic CO2 storage

Abstract Time dependence of fluid flux up a leaky well has significant implications for the feasibility of geologic CO2 storage. We present laboratory experiments that study various boundary conditions, fluid fluxes, and residence times to understand the range of behavior in fractured cement cores. Carbonic acid progressively reacts with cement by dissolving phases which neutralize the acid and liberate calcium ions. This dissolution does not increase the aperture of the fracture, due to the formation of an amorphous silicate residue. Where aqueous calcium concentration and pH are sufficiently high calcium carbonates become insoluble and precipitate in the open fracture. When the driving force for fluid flux is a constant pressure differential precipitation leads to a progressive reduction in fluid flux and the development of self-limiting behavior. With sufficient residence time precipitation leads to sealing of the leaky well.

[1]  Nobuo Hirano,et al.  Determination of aperture structure and fluid flow in a rock fracture by high‐resolution numerical modeling on the basis of a flow‐through experiment under confining pressure , 2008 .

[2]  B. Metz.  IPCC special report on carbon dioxide capture and storage , 2005 .

[3]  J. Bear.  Dynamics of Fluids in Porous Media , 1975 .

[4]  Michael A. Celia,et al.  Wellbore integrity analysis of a natural CO2 producer , 2009 .

[5]  D. Tarboton,et al.  A sediment transport model for incision of gullies on steep topography , 2003 .

[6]  P. Gouze,et al.  Hydro-dynamically controlled alteration of fractured Portland cements flowed by CO2-rich brine , 2013 .

[7]  Jean-Philippe Nicot,et al.  A survey of oil and gas wells in the Texas Gulf Coast, USA, and implications for geological sequestration of CO2 , 2009 .

[8]  S. Bryant,et al.  Experimental evidence for self-limiting reactive flow through a fractured cement core: implications for time-dependent wellbore leakage. , 2013, Environmental science & technology.

[9]  S. Walsh,et al.  Mechanical and hydraulic coupling in cement–caprock interfaces exposed to carbonated brine , 2014 .

[10]  Steven L. Bryant,et al.  An improved model to forecast CO2 leakage rates along a wellbore , 2011 .

[11]  S. Bachu,et al.  Review of integrity of existing wells in relation to CO2 geological storage: What do we know? , 2011 .

[12]  B. Berkowitz,et al.  Precipitation and dissolution of reactive solutes in fractures , 1998 .

[13]  B. Kutchko,et al.  Rate of CO2 attack on hydrated Class H well cement under geologic sequestration conditions. , 2008, Environmental science & technology.

[14]  Giovanni Grasselli,et al.  Trapping zones: The effect of fracture roughness on the directional anisotropy of fluid flow and colloid transport in a single fracture , 2006 .

[15]  S. Bachu,et al.  Evaluation of the Potential for Gas and CO2 Leakage Along Wellbores , 2009 .

[16]  Zhenhao Duan,et al.  An improved model calculating CO2 solubility in pure water and aqueous NaCl solutions from 273 to 533 K and from 0 to 2000 bar , 2003 .

[17]  Zhenhao Duan,et al.  An improved model for the calculation of CO2 solubility in aqueous solutions containing Na+, K+, Ca2+, Mg2+, Cl−, and SO42− , 2006 .

[18]  B. Kutchko,et al.  Degradation of well cement by CO2 under geologic sequestration conditions. , 2007, Environmental science & technology.

[19]  S. Walsh,et al.  Chemical and mechanical properties of wellbore cement altered by CO₂-rich brine using a multianalytical approach. , 2013, Environmental science & technology.

[20]  S. Walsh,et al.  Experimental calibration of a numerical model describing the alteration of cement/caprock interfaces by carbonated brine , 2014 .

[21]  Andrea Rinaldo,et al.  Sea level rise, hydrologic runoff, and the flooding of Venice , 2008 .

[22]  P. Zuddas,et al.  Kinetics of Calcite Precipitation from Seawater: II. The Influence of the Ionic Strength , 1998 .

[23]  D. Faivre,et al.  The influence of temperature and seawater composition on calcite crystal growth mechanisms and kinetics: Implications for Mg incorporation in calcite lattice , 2009 .

[24]  P. Lichtner,et al.  Analysis and performance of oil well cement with 30 years of CO2 exposure from the SACROC Unit, West Texas, USA , 2007 .

[25]  Stefan Bachu,et al.  Semianalytical solution for CO2 leakage through an abandoned well. , 2005, Environmental science & technology.

[26]  Jurgen Neuberg,et al.  Unprecedented pressure increase in deep magma reservoir triggered by lava‐dome collapse , 2006 .

[27]  Krishna M. Ravi,et al.  Safe and Economic Gas Wells through Cement Design for Life of the Well , 2002 .

[28]  Brian Berkowitz,et al.  Mixing-induced precipitation and porosity evolution in porous media , 2005 .

[29]  B. Berkowitz,et al.  The role of fractures on coupled dissolution and precipitation patterns in carbonate rocks , 2005 .

[30]  P. Gouze,et al.  Characterization of the mechanisms controlling the permeability changes of fractured cements flowed through by CO2-rich brine. , 2013, Environmental science & technology.

[31]  Joe M. Kang,et al.  Experimental analysis on the effects of variable apertures on tracer transport , 2003 .