Experimental study of potential wellbore cement carbonation by various phases of carbon dioxide during geologic carbon sequestration

Hydrated Portland cement was reacted with CO2 in supercritical, gaseous and aqueous phases to understand the potential cement alteration processes along the length of a wellbore, extending from a deep CO2 storage reservoir to the shallow subsurface during geologic carbon sequestration. The 3-D X-ray microtomography (XMT) images showed that the cement alteration was significantly more extensive with CO2-saturated synthetic groundwater than dry or wet supercritical CO2 at high P (10 MPa)-T (50 C) conditions. Scanning electron microscopy with energy dispersive spectroscopy (SEM–EDS) analysis also exhibited a systematic Ca depletion and C enrichment in cement matrix exposed to CO2-saturated groundwater. Integrated XMT, XRD and SEM–EDS analyses identified the formation of an extensive carbonated zone filled with CaCO3(s), as well as a porous degradation front and an outermost silica-rich zone in cement after exposure to CO2-saturated groundwater. Cement alteration by CO2-saturated groundwater for 2–8 months overall decreased the porosity from 31% to 22% and the permeability by an order of magnitude. Cement alteration by dry or wet supercritical CO2 was slow and minor compared to CO2-saturated groundwater. A thin single carbonation zone was formed in cement after exposure to wet supercritical CO2 for 8 months or dry supercritical CO2 for 15 months. An extensive calcite coating was formed on the outside surface of a cement sample after exposure to wet gaseous CO2 for 1–3 months. The chemical–physical characterization of hydrated Portland cement after exposure to various phases of CO2 indicates that the extent of cement carbonation can be significantly heterogeneous depending on the CO2 phase present in the wellbore environment. Both experimental and geochemical modeling results suggest that wellbore cement exposure to supercritical, gaseous and aqueous phases of CO2 during geologic C sequestration is unlikely to damage the wellbore integrity because cement alteration by all phases of CO2 is dominated by carbonation reactions. This is consistent with previous field studies of wellbore cement with extensive carbonation after exposure to CO2 for three decades. However, XMT imaging indicates that preferential cement alteration by supercritical CO2 or CO2-saturated groundwater can occur along the cement–steel or cement–rock interfaces. This highlights the importance of further investigation of cement degradation along the interfaces of wellbore materials to ensure permanent geologic carbon storage. Published by Elsevier Ltd.

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

[2]  F. Lea.  The chemistry of cement and concrete , 1970 .

[3]  J. Carey,et al.  Geochemical effects of CO2 sequestration on fractured wellbore cement at the cement/caprock interface , 2009 .

[4]  A. Neville.  Properties of Concrete , 1968 .

[5]  S. Simons,et al.  A review of accelerated carbonation technology in the treatment of cement-based materials and sequestration of CO2. , 2004, Journal of hazardous materials.

[6]  F. Brunet,et al.  Heterogeneous Porosity Distribution in Portland Cement Exposed to CO2-rich Fluids , 2008 .

[7]  J William Carey,et al.  Experimental evaluation of wellbore integrity along the cement-rock boundary. , 2013, Environmental science & technology.

[8]  Tianfu Xu,et al.  Injection of Supercritical CO2 Into Deep Saline Carbonate Formations: Predictions From Geochemical Modeling , 2011 .

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

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

[11]  Shuguo Ma,et al.  Potential for carbon adsorption on concrete: surface XPS analyses. , 2008, Environmental science & technology.

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

[13]  Michael A. Celia,et al.  Spatial characterization of the location of potentially leaky wells penetrating a deep saline aquifer in a mature sedimentary basin , 2004 .

[14]  R. Wilkin,et al.  Geochemical impacts to groundwater from geologic carbon sequestration: controls on pH and inorganic carbon concentrations from reaction path and kinetic modeling. , 2010, Environmental science & technology.

[15]  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 .

[16]  S. Bachu,et al.  Experimental assessment of brine and/or CO2 leakage through well cements at reservoir conditions , 2009 .

[17]  Karsten Pruess,et al.  CO2-H2O mixtures in the geological sequestration of CO2. I. Assessment and calculation of mutual solubilities from 12 to 100°C and up to 600 bar , 2003 .

[18]  Zhenhao Duan,et al.  The speciation equilibrium coupling with phase equilibrium in the H2O–CO2–NaCl system from 0 to 250 °C, from 0 to 1000 bar, and from 0 to 5 molality of NaCl , 2007 .

[19]  D. L. Parkhurst,et al.  User's guide to PHREEQC (Version 2)-a computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations , 1999 .

[20]  E. Ilton,et al.  In situ infrared spectroscopic study of forsterite carbonation in wet supercritical CO2. , 2011, Environmental science & technology.

[21]  R. Jackson,et al.  Potential impacts of leakage from deep CO2 geosequestration on overlying freshwater aquifers. , 2010, Environmental science & technology.

[22]  Veronique Barlet-Gouedard,et al.  Mitigation strategies for the risk of CO2 migration through wellbores , 2006 .

[23]  M. Engelhard,et al.  The role of H2O in the carbonation of forsterite in supercritical CO2 , 2011 .

[24]  Michael A. Celia,et al.  Leakage of CO 2 Through Abandoned Wells: Role of Corrosion of Cement , 2005 .

[25]  G. Scherer,et al.  Degradation of oilwell cement due to exposure to carbonated brine , 2010 .

[26]  Karsten Pruess,et al.  Formation dry‐out from CO2 injection into saline aquifers: 1. Effects of solids precipitation and their mitigation , 2009 .

[27]  J. Hansen,et al.  Climate Impact of Increasing Atmospheric Carbon Dioxide , 1981, Science.

[28]  B. Kutchko,et al.  CO2 reaction with hydrated class H well cement under geologic sequestration conditions: effects of flyash admixtures. , 2009, Environmental science & technology.

[29]  Catherine A Peters,et al.  Safe storage of CO2 in deep saline aquifers. , 2002, Environmental science & technology.

[30]  V. Lagneau,et al.  Experimental measurement of portlandite carbonation kinetics with supercritical CO2 , 2009 .

[31]  P. F. Martin,et al.  Effective Permeability Change in Wellbore Cement with Carbon Dioxide Reaction , 2011 .

[32]  John S Gierke,et al.  Carbon dioxide sequestration in cement kiln dust through mineral carbonation. , 2009, Environmental science & technology.

[33]  P. F. Martin,et al.  Brucite [Mg(OH2)] carbonation in wet supercritical CO2: An in situ high pressure X-ray diffraction study , 2011 .

[34]  Christopher J. Spiers,et al.  Fracture healing and transport properties of wellbore cement in the presence of supercritical CO2 , 2011 .

[35]  Wooyong Um,et al.  Imaging wellbore cement degradation by carbon dioxide under geologic sequestration conditions using X-ray computed microtomography. , 2013, Environmental science & technology.