Energy and Environmental Systems Group Institute for Sustainable Energy, Environment and Economy (ISEEE) Well Design and Well Integrity WABAMUN AREA CO2 SEQUESTRATION PROJECT (WASP) Author Runar Nygaard Rev. Date Description Prepared by 1 January 4, 2010 Well Design and Well Integrity Runar Nygaard Table of Contents INTRODUCTION ........................................................................................................................................... 5 BACKGROUND ............................................................................................................................................ 5 DISCUSSION ................................................................................................................................................ 5 1. WELL DESIGN AND POTENTIAL LEAKAGE PATHS ............................................................................ 5 2. EFFECT OF CO2 INJECTION ON WELL CONSTRUCTION MATERIALS ............................................ 7 2.1 Cement ............................................................................................................................................. 7 2.2 Oil Well Cements ............................................................................................................................. 8 2.3 CO2 Effect on Portland Cements ................................................................................................... 11 2.4 CO2 Corrosion on Tubulars and Steel Components ...................................................................... 17 2.5 Mechanical Effects on Wellbore ..................................................................................................... 18 3. WELL INJECTION DESIGN ................................................................................................................... 19 3.1 Geological Description of Well Location ........................................................................................ 19 3.2 Casing Design ................................................................................................................................ 21 3.3 Cementing Design .......................................................................................................................... 22 3.4 Completion Design ......................................................................................................................... 23 4. INJECTION WELL COST ESTIMATE ................................................................................................... 24 5. ABANDONMENT OF WELLS ................................................................................................................ 27 6. EVALUATION OF EXISTING WELLS IN NISKU ................................................................................... 29 7. CONCLUSIONS ..................................................................................................................................... 35 8. REFERENCES ....................................................................................................................................... 36 Appendix A .................................................................................................................................................. 38 Wabamun Area CO2 Sequestration Project (WASP) Page 2 of 39 Well Design and Well Integrity List of Tables Table 1: Regular Portland cement briefly described the different classes as specified in API Specification 10A and ASTM Specification C150. ........................................................................................ 9 Table 2: Brief description of special cements (Meyer, 2008; Schlumberger, 2009; Halliburton, 2009). ..... 10 Table 3: Materials of construction (MOC) for CO2 injection wells based on US experience (Meyer, 2008). ............................................................................................................................................. 18 Table 4: Well cost model WASP project injection well. ............................................................................... 24 Table 5: Well cost results WASP project injection well. .............................................................................. 25 Table 6: Tubular and cementing costs for a vertical well. ........................................................................... 26 Table 7: Drilled and abandoned wells in focus area. .................................................................................. 33 Table 8: Drilled, cased and abandoned wells. ............................................................................................ 34 Wabamun Area CO2 Sequestration Project (WASP) Page 3 of 39 Well Design and Well Integrity List of Figures Figure 1: Example of possible leakage paths for CO2 in a cased wellbore (Celia et al, 2004). ................... 6 Figure 2: Well design and abandonment of wells in the Wabamun Lake area (ERCB, 2007; Watson and Bachu, 2007). ......................................................................................................................................... 7 Figure 3: Illustration of the chemical reactions zones in cement casing. First Zone Ca(OH)2 3 dissolves and CaCO forms. Second Zone CaCO3 dissolves when Ca(OH)2 is spent (Kutchko et al, 2007). .................................................................................................................................. 12 Figure 4: Rate of carbonation for Portland cement from laboratory tests, Barlet-Gouédard et al (2006). ......................................................................................................................................................... 13 Figure 5: Carbonation depth (mm) versus time (days) at 50˚C (Kutchko et al, 2008). ............................... 14 Figure 6: Test of Class H Portland cement in CO2 saturated fluid (Kutchko et al, 2008). .......................... 15 Figure 7: Validation of CO2 durability of different cement systems (Barlet-Gouedard et al, 2008). ........... 16 Figure 8: Photograph of samples recovered from the 49-6 well in Texas. It shows the casing (left), gray cement with a dark ring adjacent to the casing, 5 cm core of gray cement, gray cement with an orange alteration zone in contact with a zone of fragmented shale, and the shale country rock (Carey et al, 2007). ..................................................................................................................................... 16 Figure 9: Well design for vertical injection well. .......................................................................................... 20 Figure 10: Vertical and least horizontal stress and pore pressure gradients (Michael et al, 2008). ........... 21 Figure 11: Carbonation depth estimated from laboratory tests after 100 year. .......................................... 23 Figure 12: Drilling time for vertical well estimated based on three reference wells in the area. ................. 25 Figure 13: Schematic of using metal alloy plug to seal and abandon production zone (Canitron, 2008). .......................................................................................................................................................... 28 Figure 14: Suggested abandonment method for CO2 injection wells. ........................................................ 29 Figure 15: Age distribution of wells drilled through Nisku in the study area. Gray wells are drilled and abandoned, white wells are drilled and cased wells. ........................................................................... 30 Figure 16: Flow chart for identifying wells which are candidates for re-entering and conduct workover operations to improve leakage integrity. ..................................................................................... 31 Figure 17: Outline of the study area where horizontal lines are Ranges West of 5 and Vertical squares are Townships. The highlighted area is the focus area where all 27 wells where studied in detailed. Twelve additional wells where randomly selected (indicated in green). ...................................... 32 Figure 18: Spatial distribution of all wells penetrating Nisku in the study area. .......................................... 34 Wabamun Area CO2 Sequestration Project (WASP) Page 4 of 39 Well Design and Well Integrity INTRODUCTION BACKGROUND To successfully inject CO2 into the subsurface to mitigate green house gases in the atmosphere, the CO2 must to be trapped in the subsurface and not be allowed to leak to the surface or to potable water sources above the injection horizon. Potential leakage can occur through several different mechanisms, including natural occurrences or along wells. To avoid leakage from injection wells, the integrity of the wells must be maintained during the injection period and for as long as free CO2 exists in the injection horizon. In addition to injection wells, monitoring wells will most likely be required to observe the plume movement and possible leakage. The Environmental Protection Agency (EPA) in the United States has stated that its goal is to be able to account for 99% of the CO2 injected (NETL, 2009). The experience from more than 100 CO2 enhanced oil recovery (EOR) projects over the last 30 years has shown that CO2 can be successfully transported and injected into a reservoir in the subsurface (Moritis, G. 2008). CO2 EOR projects, along with wells drilled in H2S-rich environments and high-temperature geothermal projects, have