6 DRILLING AND COMPLETIONS

Transcription

1 Cenovus FCCL Ltd. 6-1 Drilling and Completions 6 DRILLING AND COMPLETIONS 6.1 OVERVIEW This section contains information about the drilling and completion of wells within the CLTP. Well counts, locations and timing are provided in Sections 5 and 8. This section also discusses well thermal compatibility; for information regarding thermal containment with respect to caprock, please refer to Sections and DRILLING AND COMPLETIONS OBJECTIVES All new wells will be applied for through the ERCB licensing processes (ERCB Directive 051: Injection and Disposal Wells Well Classifications, Completions, Logging at Testing Requirements [EUB 1994] and ERCB Directive 050: Drilling Waste Management [EUB 1996a]) and necessary regulatory approvals will be obtained prior to any surface disturbance. 6.3 PRODUCTION WELLS SAGD Well Pairs The CLTP SAGD pads generally have between, but are not limited to, 8 to 16 well pairs. The exact number of well pairs per pad is dependent on the spacing between well pairs and reservoir area accessed. An aerial view of the modelled drilling trajectories of the CLTP B01 pad is provided in Figure Each well pair includes a production well and an injection well (Figure 6.3-2); however, when plotted in two dimensions from an aerial view only a single well (line) is visible as demonstrated in figures and Horizontal wells will be started vertically and drilled at build rates of approximately 10 degrees per 30 m and build inclination to 90 degrees from vertical. The horizontal sections will have an average True Vertical Depth (TVD) of 350 to 450 m from the surface, and will typically be approximately 800 m in

2 Cenovus FCCL Ltd. 6-2 Drilling and Completions horizontal length. Overall, the total well length will average approximately 1,400 m Measured Depth (MD). The surface hole will be drilled, cased and cemented in place with thermal cement. The surface casing design will meet the requirements of ERCB Directive 008: Casing Depth Requirements (ERCB 2010d). The intermediate hole will typically be drilled vertically to the kick-off depth at which point directional drilling begins. The intermediate hole will be drilled using a directional drilling package. Once the horizontal section is reached, the intermediate casing is cemented to surface using thermal cement. Careful attention to borehole quality and casing centralization design and placement are made to ensure cement zonal isolation. The horizontal main hole will be drilled with a measurement while drilling assembly to evaluate the formation encountered along the horizontal section. A sand-control liner is then run the length of the horizontal section and is hung inside the intermediate casing. The liner is not cemented in the well. The SAGD well pairs are drilled in a batch process starting with all surfaces intervals for both the producers and injectors. To reduce drilling costs and maximize cement compressive strength development time, the production well intermediate sections are drilled and cased in succession on a pad, followed by the production well horizontal section. The pad s injection wells would then be drilled in a similar manner. Horizontal sections of the injection wells will be drilled approximately 5 m above the production wells. Consistent vertical spacing is maintained by using a magnetic guidance system. The start of the horizontal section is typically referred to as the heel of the well and the end is the toe. The horizontal sections are usually drilled slightly upward a few metres over the last few hundred metres of horizontal section approaching the toe. This drilling technique promotes fluid flow toward the heel of the well which aids in production. The completions of the SAGD well pair are discussed in Sections and

3 Cenovus FCCL Ltd. 6-3 Drilling and Completions Drilling Constraints Cenovus constrains the drilling of well pairs for various reasons to achieve optimum performance of each SAGD well pair. The following list details the drilling constraints Cenovus uses for all of its well pairs: In the absence of bottom water the lower production well profile is generally targeted approximately 1 to 2 m above the SAGD Base. Due to measurement while drilling uncertainty this often leads to hitting SAGD Base and drilling up to get above SAGD Base. If bottom water exists (without a shale break) placement may vary to optimize recovery. Profile directional changes are planned at less than two degrees to minimize drilling and completion difficulties (i.e., slotted liner placement). Borehole-position uncertainty during drilling (generally +/- 2 m at heel and +/- 5 m at toe) often leads to hitting the SAGD Base. Cenovus adjusts the well trajectory upwards if longer than expected intervals with high gamma readings are encountered (to get back above SAGD Base). Wellbore elevation drops, especially near the toe, can occur while drilling. Borehole-position and reservoir uncertainty will contribute to operational adjustments during drilling. Proposed well profiles may be different from final drilled/surveyed trajectories, depending on encountered subsurface conditions. In sections where there is uncertainty about the presence or extent of permeability barriers that could significantly impact well placement decisions, it is Cenovus s practice to drill open-hole sidetracks to further evaluate the reservoir and then, while drilling, re-evaluate the trajectory based on this additional information.

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6 Cenovus FCCL Ltd. 6-6 Drilling and Completions Start-up/ Gas Lift Completions A SAGD well pair is initially completed for start-up of the well pair and the gas lift mode of production. The gas lift mode supports the ramp up phase of the SAGD chamber. Typical injector and producer completion schematics are shown in Figures and 6.3-4, respectively Electric Submersible Pump Completions The ESP mode of production covers all remaining productive phases of the SAGD chamber. For the ESP mode only the producer well completion is altered. A typical producer well in ESP mode is displayed in Figure Wedge Wells A Wedge Well is drilled and completed similarly to a SAGD producer well as described in Section Wedge Wells are drilled in between two SAGD well pairs in order to increase reservoir recovery and SAGD operating efficiency. An aerial view of a SAGD pad with Wedge Wells is shown in Figure A Wedge Well is expected to be typically completed in the ESP mode which is shown in Figure WATER WELLS Water Disposal Wells The CLTP s water disposal wells access the Basal McMurray Aquifer. Disposal wells will comply with ERCB directives in terms of drilling, completions, testing and volumetric monitoring.

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12 Cenovus FCCL Ltd Drilling and Completions A water disposal well is started vertically with a surface hole similar to the one described for the SAGD well pair. The main hole is then drilled following a vertical or deviated trajectory. The hole is then cased, cemented and completed with perforations. A typical water disposal well completion is shown in Figure The CLTP water disposal wells have an average TVD of 450 m and typically range from 450 m to 550 m in MD Water Source Wells Clearwater B The CLTP currently uses saline water from the Clearwater B Formation for make-up water required for steam generation for Phases A to E. A water source well is started vertically with a surface hole similar to the one described for the SAGD well pair. The main hole is then drilled following a vertical or deviated trajectory. This hole is then cased, cemented and completed with a sand control device such as a wire wrapped screen or a liner. The water is pumped to the surface using an ESP. A typical Clearwater B water source well completion is shown in Figure The CLTP Clearwater B water source wells have an average TVD of 350 m and typically range from 1,000 to 1,300 m in MD McMurray The CLTP plans to use saline water from the McMurray Formation for make-up water required for steam generation for Phases F to H. The McMurray source well is drilled and completed in a similar manner to the Clearwater B well but it will be accessing the Basal McMurray Aquifer. The CLTP McMurray water source wells will have an average TVD of 450 m and typically range from 1,100 m to 1,400 m in MD.

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15 Cenovus FCCL Ltd Drilling and Completions Fresh Water Wells The CLTP s fresh water wells access the Tertiary Empress Formation. The CLTP strives to minimize fresh water usage. These wells are drilled and completed in a similar fashion to the saline source wells, with the exception that these wells are drilled vertically from top to bottom. The CLTP fresh water wells have an average TVD and MD of less than 100 m. 6.5 DELINEATION (STRAT) WELLS Delineation (strat) or Oil Sands Exploration (OSE) wells are used to understand and define the McMurray Formation as well as plan SAGD well pair orientation and drilling trajectory. In many cases additional delineation wells are required along the planned SAGD well pair trajectories when the reservoir has a high variation of SAGD Base along the length of the horizontal wells. A strat well is drilled with a vertical surface and main hole. These strat wells are logged and can also be used to obtain SAGD (steam) chamber cores. During logging just the surface hole is cased and cemented. Afterwards the well is usually abandoned. The CLTP strat wells have an average TVD and MD of 500 m. 6.6 OBSERVATION WELLS Several wells initially drilled to obtain geological information via well logging may ultimately serve a dual purpose as observation wells for SAGD operations, in which case the main hole is also cemented and cased, and subsequently instrumented. A typical completion of an observation well is shown in Figure

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17 Cenovus FCCL Ltd Drilling and Completions All delineation wells will be applied for in accordance with the licensing processes and the appropriate regulatory bodies will be contacted and consulted for approval as required. Observation wells provide valuable temperature or pressure information which can aid in determining SAGD chamber growth. Observation wells are usually placed along the trajectory of a SAGD well pair and monitored as required. All observation and delineation wells will be applied for in accordance with the licensing processes through the appropriate regulatory bodies. 6.7 WELL INTEGRITY Cenovus strives for safe, compliant, and environmentally conscious operations; therefore, containment of the SAGD process is a key objective. Understanding and monitoring well and caprock integrity allows the CLTP to meet this objective. Within the CLTP there are numerous wells that are expected to interact with SAGD chambers, either directly or indirectly. Due to the pressure and temperature of SAGD operations, it is critical that wells interacting with SAGD operations are thermally compatible to maintain containment of the SAGD chamber. Thermal compatibility requires use of casing and cement that resist deformation and failure when exposed to SAGD operations. A database of wells within the PPA plus a 600 m buffer has been compiled to track and analyze wells that may be affected by SAGD operations. Analysis of the database indicates 40 wells (out of a total of 781) may not be thermally These wells may require remediation and/or monitoring prior to exposure of SAGD operations.

18 Cenovus FCCL Ltd Drilling and Completions Thermal Compatibility Assessment Criteria The process and criteria used by Cenovus to assess the thermal compatibility of existing wells that may be impacted by the proposed thermal operations is described below. Open-hole Well Assessment 1. Assess drill depth of existing well. a. If the total depth is less than the depth of the Clearwater B (T31) shale top, then the assessment is not required. b. If the total depth is greater than the depth of the Clearwater B (T31) shale top, then the assessment proceeds to Step 2. Rationale: The Clearwater B (T31) shale top is the upper extent of the caprock containing the SAGD chamber, so if the existing well does not penetrate this layer, there is no containment risk associated with the thermal operations. 2. Assess the abandonment details of the existing well. a. If the well has been abandoned in compliance with ERCB Directive 020 (ERCB 2010e) and with thermal cement, then the assessment is complete and the well is thermally b. If the well has not been abandoned in compliance with ERCB Directive 020 or abandoned without thermal cement, then the well is not thermally compatible and mitigation may be required. Rationale: If the well has been thermally abandoned properly, then there is no risk to fluid containment.

19 Cenovus FCCL Ltd Drilling and Completions Cased-hole Well Assessment 1. Assess drill depth of the existing well. a. If the depth is less than the depth of the Clearwater B (T31) shale top, then the assessment is not required. b. If the depth is greater than the depth of the Clearwater B (T31) shale top, then assessment proceeds to Step 2. Rationale: The Clearwater B (T31) shale top is the upper extent of the caprock containing the SAGD chamber, so if the existing well does not penetrate this layer, there is no containment risk associated with the thermal operations. 2. Assess status of the existing well. a. If the well is abandoned, then the assessment proceeds to Step 3. b. If the well is not abandoned, then the assessment proceeds to Step Assess abandonment details of the existing well. a. If the well has been abandoned in compliance with ERCB Directive 020 and with thermal cement, then the assessment is complete and the well is thermally b. If the well has not been abandoned in compliance with ERCB Directive 020 or abandoned without thermal cement, then the well is not thermally compatible and mitigation may be required. Rationale: If the well has been properly thermally abandoned, then there is no risk to fluid containment. 4. Assess casing material of the existing well. a. If the casing material is thermally compatible and assessment proceeds to Step 5.

20 Cenovus FCCL Ltd Drilling and Completions b. If the casing material is not thermally compatible and mitigation may be required. Assessment continues to Step 5. Rationale: Thermally compatible casing will have adequate strength at temperatures associated with thermal recovery schemes. 5. Assess casing connections of existing well. a. If the casing connections are buttress thread or better, then the casing connections are thermally compatible and assessment proceeds to Step 6. b. If the casing connections are not buttress thread or better, then the casing connections are not thermally compatible and mitigation may be required. Assessment continues to Step 6. Rationale: Buttress thread or better provides adequate hydraulic sealing at temperatures associated with thermal recovery schemes. 6. Assess the casing cement blend of the existing well. a. If the casing cement blend is thermally rated, then the casing cement blend is thermally compatible and assessment proceeds to Step 7. b. If the casing cement blend is not thermally rated, then the casing cement blend is not thermally compatible and mitigation may be required. Assessment continues to Step 7. Rationale: Thermally rated cement blends are specifically formulated to be compatible with the temperatures associated with thermal recovery schemes.

21 Cenovus FCCL Ltd Drilling and Completions 7. Assess the casing cement top for the existing well. a. If the casing cement returns are greater than 0.1 m 3, then the cement job is thermally compatible and assessment proceeds to Step 8. b. If the cement returns are not greater than 0.1 m 3, then a cement bond log needs to be assessed. i. If the cement bond log shows acceptable bonding to both the casing and the outer wall of the well bore from the Clearwater B (T31) shale top to the McMurray Formation top, then cement job is thermally compatible and assessment proceeds to Step 8. ii. If the cement bond log does not show acceptable bonding to both the casing and the outer wall of the well bore from the Clearwater B (T31) shale top to the McMurray top, then cement job is not thermally compatible and mitigation may be required. Assessment continues to Step 8. Rationale: An acceptable cement return value indicates that there is adequate sealing of the annulus between the casing and the outer wall of the well bore so that there is no path for fluid or gas migration. If the cement return values are not acceptable, then a cement bond log is an alternate method for assessing adequate annulus sealing in the specific area of interest. An acceptable bond log in the caprock indicates that there is adequate sealing of the annulus between the casing and the formation so that there is no path for fluid migration above the caprock due to thermal operations. 8. Assess the existence of perforations in the existing well. a. If there have been no perforations in the McMurray Formation, the well is thermally compatible and assessment is complete. b. If the perforations exist in the McMurray Formation, then proceed to Step 9.

22 Cenovus FCCL Ltd Drilling and Completions Rationale: If there are no perforations in the McMurray Formation, then there is no pathway for fluid to migrate from the formation into the wellbore due to thermal operations. 9. Assess the status of perforations in the McMurray Formation in the existing well. a. If the perforations in the McMurray Formation have been abandoned in compliance with ERCB Directive 020 and with thermal cement, the perforations are thermally compatible and assessment is complete. b. If the perforations in the McMurray Formation are open then perforations are not thermally compatible and mitigation may be required. Assessment is complete. Rationale: If the perforations have been properly thermally abandoned, then there is no pathway for fluid to migrate from the formation into the wellbore due to thermal operations Assessment Results Cenovus used the previous described assessment criteria to assess the wells in the well database that was compiled. This database includes all wells within the PPA plus a 600 m buffer. This well database is provided in Appendix 1-VI. The wells listed in Table may not be thermally compatible and mitigation may be required. A total of 28 wells that do not meet the aforementioned thermal compatibility criteria have been identified. In addition to these 28 wells, the study encountered 12 additional wells where records do not clearly indicate the presence or absence of thermal casing and cement. Until proven otherwise it will be assumed these 12 wells are non-thermally compatible and they will be further investigated and remediated as required. The locations of the above combined total of up to 40 non-thermally compatible wells are shown in Figure Cenovus believes there is no risk to thermal operations in the vicinity of the aforementioned 40 non-thermally compatible wells, as long as the following suggested monitoring, mitigation and/or remediation plans are implemented.

23 Cenovus FCCL Ltd Drilling and Completions The non-thermally compatible wells have been divided into the following four subcategories, which are also highlighted in Table and Figure 6.7-1: i. Thermal casing was used but not thermal cement. ii. Thermal cement was used but not thermal casing. iii. Neither thermal casing or thermal cement were used. iv. Thermal cement was not used to abandon (no casing below surface casing depth). The expected year that a SAGD chamber could interact with the 40 non-thermally compatible wells is illustrated in Table and Figure This expected year is based on current development plans and is subject to change due to regulatory approvals and market conditions.

24 Cenovus FCCL Ltd Reservoir and Recovery Process Table Thermal Compatibility Assessment Results Summary UWI Licensee Name License # Rig Release Date Status TD (mmd) Formation at TD Perforation (m) Size (mm) Depth (mmd) Grade Casing Intermediate / Production Casing For Abandoned Wells Only Weight (kg/m) Thread Type Returns (m 3 ) Size (mm) Depth (mmd) Grade Weight (kg/m) Thread Type Returns (m 3 ) Type Plugs Depth (m) Returns (m 3 ) Non-Thermal Category Type Clear or Unclear Expected SAGD Chamber Interaction Year Comments 100/ ExxonMobil Rsrcs Comp /8/1981 Abandoned N/A H ST&C Oilwell Class 'G'+2.5% Good N/A N/A N/A N/A N/A N/A N/A Oilwell Class 'G' Clear is nonthermally 100/ /7/1979 Abandoned ; ; ; ; H ST&C Normal Portland +3% J ST&C Thermal 40 EXP+2% +0.25% CFL-3 Good N/A N/A 2 Clear Production casing and connection are not thermally rated. Canadian 100/15- Natural Resources 06W4/02 Ltd /5/1980 Suspended H ST&C Normal Portland +2.5% Fair J ST&C Oilwell neat cement+0.5 % D-19 Good N/A N/A N/A 3 Clear Production casing and connection are not thermally rated. is non-thermally 100/ W4/03 MEG Energy Phillips 100/09- Petroleum Resources 05W4/00 Ltd 100/ W4/02 100/ W4/02 100/ W4/02 1AA/ MEG Energy /13/1977 Producing; Suspended; Abandoned /2/1991 Abandoned /29/1980 Standing Clearwater Formation /13/1998 Suspended McMurray Formation /1/1992 Gas /23/2003 Abandoned McMurray Formation ; ; H-40 N/A N/A "120 sacs" N/A N/A N/A N/A N/A N/A N/A N/A H ST&C ; ; ; ; ; ; ; H ST&C J ST&C H ST&C N/A H ST&C 0.60 N/A N/A N/A N/A N/A N/A N/A N/A J ST&C J ST&C J ST&C H ST&C Class 'A'+2% Gel Trican Mix II+2% +0.1% SPC % CFL-2 THERMAL % C C101 THERMAL % +0.25% CFL-3 Class 'G'+0.75% CFR #3 Packer set at 353.5; Packer set at 371 N/A 3 UnClear Good 4 Clear N/A N/A N/A 3 Clear N/A N/A N/A 3 Clear N/A Packer set at 237; Plugs landed at N/A 2 Clear N/A N/A N/A 2 Clear Assume production casing and connection are not thermally rated. is assumed non-thermally is nonthermally Production casing and connection are not thermally rated. is assumed nonthermally Production casing and connection are not thermally rated. is assumed nonthermally Production casing and connection are not thermally rated. Production casing and connection are not thermally rated. Volume 1, Section 5

25 Cenovus FCCL Ltd Drilling and Completions Table Thermal Compatibility Assessment Results Summary (continued) UWI Licensee Name License # Rig Release Date Status TD (mmd) Formation at TD Perforation (m) Size (mm) Depth (mmd) Grade Casing Intermediate / Production Casing For Abandoned Wells Only Weight (kg/m) Thread Type Returns (m 3 ) Size (mm) Depth (mmd) Grade Weight (kg/m) Thread Type Returns (m 3 ) Type Plugs Depth (m) Returns (m 3 ) Non-Thermal Category Type Clear or Unclear Expected SAGD Chamber Interaction Year Comments 100/ W4/03 100/ / / / AA/ AA/ / AA/ AA/ AA/ AA/ AA/ AA/ /13/1979 Abandoned /27/1998 Water Disposal /23/2002 Abandoned McMurray Formation /14/1976 Suspended McMurray Formation /23/1994 Abandoned /19/1981 Abandoned /9/1981 Abandoned /25/1978 Abandoned /5/1981 Abandoned /3/1981 Abandoned /12/1981 Abandoned /18/1981 Abandoned /22/1981 Abandoned /27/1981 Abandoned ; ; ; ; ; ; ; H ST&C J ST&C H ST&C ; ; ; ; K ST&C H ST&C N/A H ST&C N/A H ST&C ; ; ; H ST&C N/A H ST&C N/A H ST&C N/A H ST&C N/A H ST&C N/A H ST&C N/A H ST&C oil well cement+3% Class 'G'+3% Celloflake Oil well cement 'G'+3% Class 'G'+3% Class 'G' Oil Well +3% Good J F J ST&C J ST&C Good K F J ST&C Thermal 40 EXP+2% +0.25% CFL-3 THERMAL % CFL-2+2% THERMAL % CFL-2+2% 260 SKS Oil Well +4% Gel Thermal 40 EXP+3% +0.25% CFL N/A N/A N/A N/A N/A N/A N/A 3.0 N/A N/A 2 UnClear N/A N/A N/A 2 Clear N/A Packer set at 202 N/A 2 Clear N/A N/A N/A N/A 2 UnClear N/A N/A N/A 2 Clear Class 'G'+0.1% HR-4 Good N/A N/A N/A N/A N/A N/A N/A Class 'G' Good N/A N/A N/A N/A N/A N/A N/A N/A Good N/A N/A N/A N/A N/A N/A N/A N/A 1.50 N/A N/A N/A N/A N/A N/A N/A 1.00 N/A N/A N/A N/A N/A N/A N/A 1.50 N/A N/A N/A N/A N/A N/A N/A 1.50 N/A N/A N/A N/A N/A N/A N/A 0.50 N/A N/A N/A N/A N/A N/A N/A Class 'G'+0.1% HR-4 Class 'G' Inland Bulk cement+0.1 % HR-4 Class 'G' Inland Bulk cement+0.1 % HR-4 Class 'G'+0.1% Retarder Class 'G'+0.1% HR 4 N/A 4 Clear N/A 4 Clear N/A 4 UnClear N/A 4 Unclear N/A 4 Clear N/A 4 Clear N/A 4 Clear Clear Good 4 Clear Assume production casing and connection are not thermally rated. Production casing and connection are not thermally rated. Production casing and connection are not thermally rated. Assume production casing and connection are not thermally rated. Production casing and connection are not thermally rated. is nonthermally is nonthermally Assume cement is non-thermally Assume cement is non-thermally is nonthermally is nonthermally is nonthermally is nonthermally is nonthermally

26 Cenovus FCCL Ltd Drilling and Completions Table Thermal Compatibility Assessment Results Summary (continued) UWI Licensee Name License # Rig Release Date Status TD (mmd) Formation at TD Perforation (m) Size (mm) Depth (mmd) Grade Casing Intermediate / Production Casing For Abandoned Wells Only Weight (kg/m) Thread Type Returns (m 3 ) Size (mm) Depth (mmd) Grade Weight (kg/m) Thread Type Returns (m 3 ) Type Plugs Depth (m) Returns (m 3 ) Non-Thermal Category Type Clear or Unclear Expected SAGD Chamber Interaction Year Comments 100/ W4/ /14/1980 Gas Flowing H ST&C J N/A N/A N/A N/A N/A N/A 3 UnClear Assume production casing and connection are not thermally rated. is assumed non-thermally 100/ W4/00 100/ W4/00 Compton Petroleum /11/2002 Abandoned Clearwater Formation /14/1992 Abandoned /13- Perpetual W4/00 Energy Inc /12/1988 Suspended Canadian 1AA/10- Natural Resources 05W4/00 Ltd 100/10- Suncor W4/00 Energy Inc /25/1978 Abandoned /10- Suncor Energy Inc. 05W4/00 100/15- NEC W4/ H ST&C ; ; ; ; ; J ST&C H ST&C Class "A"+2% +0.2 Cellophane J ST&C J ST&C J ST&C THERMAL 40+2% +0.4% CFL-2 Class 'G'+40% C- 105 (Silica Flour)+0.75% C-100 (Turflow)+0.7 5% C-101 (FLA) Class G+3% Silica+0.5% CFR+0.5% CFL +0.2 Cellophane 1.0 N/A 0.75 Class G Thermal 8m bridge plug of cement N/A 2 Clear Good 2 Clear N/A N/A N/A 3 Clear N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 4 Unclear /8/1978 McMurray Abandoned Formation /21/1998 Standing /10- Suncor W4/00 Energy Inc /17/1974 Abandoned /10- Suncor W4/00 Energy Inc /27/1977 Abandoned N/A H-40 N/A ST&C N/A K ST&C ; ; ; ; ; ; J ST&C N/A H ST&C N/A H ST&C Class 'G'+2% Class 'G'+3% N/A N/A N/A N/A N/A N/A N/A N/A 60 SKS J ST&C J ST&C Class 'A'+2% Gel Trican Mix II+2% +0.1% SPC % CFL-2 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2 Class 'G'+0.75% CFR # UnClear Clear N/A N/A N/A 3 Clear Class 'G'+0.75% CFR #3 Class 'G'+0.75% CFR #3 Good 4 Clear Clear Production casing and connection are not thermally rated. Production casing and connection are not thermally rated. Production casing and connection are not thermally rated. is assumed nonthermally Assume cement is non-thermally Assume cement is non-thermally Production casing and connection are not thermally rated. is non-thermally is nonthermally is nonthermally is nonthermally 100/10- Suncor /20/1979 Abandoned N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Class A+3% Clear is non-

27 Cenovus FCCL Ltd Drilling and Completions Table Thermal Compatibility Assessment Results Summary (continued) UWI Licensee Name License # Rig Release Date Status TD (mmd) Formation at TD Perforation (m) Size (mm) Depth (mmd) Grade Casing Intermediate / Production Casing For Abandoned Wells Only Weight (kg/m) Thread Type Returns (m 3 ) Size (mm) Depth (mmd) Grade Weight (kg/m) Thread Type Returns (m 3 ) Type Plugs Depth (m) Returns (m 3 ) Non-Thermal Category Type Clear or Unclear Expected SAGD Chamber Interaction Year Comments Energy Inc. 05W4/00 100/10- Suncor Energy Inc. 05W4/00 100/ W4/00 1AA/ W4/00 100/ W4/00 100/ W4/00 1AA/ W4/00 MEG Energy MEG Energy MEG Energy MEG Energy MEG Energy /3/1975 Abandoned /25/2004 Standing McMurray Formation /1/2011 Abandoned McMurray Formation /12/2011 Standing McMurray Formation /1/2000 Abandoned McMurray Formation /10/2012 Abandoned McMurray Formation N/A H ST&C ; N/A N/A N/A N/A N/A N/A N/A N/A thermally Class A+3% Good 4 Clear H ST&C N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 3 UnClear N/A N/A N/A N/A N/A good N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 4 Unclear N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 3 UnClear H ST&C J ST&C THERMAL % FL- 6+2% 2.0 N/A Packer set at 320m N/A 2 Clear N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 4 UnClear is nonthermally Assume cement is non-thermally Assume nonthermally Assume production casing and connection are not thermally rated. is assumed non-thermally Production casing and connection are not thermally rated. Assume nonthermally

28 LEGEND Sawbones Creek + ROAD Tp.77 Rg.6 W4M Tp.77 Rg.5 W4M Tp.77 Rg.4 W4M WATERCOURSE WATERBODY THERMAL COMPATIBILITY CLEARLY NON-THERMALLY COMPATIBLE WELL UNCLEAR THERMAL COMPATIBILITY -TREAT AS NON-THERMALLY COMPATIBLE CLTP PROPOSED PROJECT AREA (PPA) I:\CLIENTS\CENOVUS\ \mapping\mxd\Volume_1\EIA_Figures\FINAL\ _EIA_V1_012.mxd ~650m A31 A35 Sunday Creek Q ~175m A23 Q07 A19 A33 A29 A25 A37 Q03 A27 Tp.76 Rg.6 W4M Q05 A15 A21 A39 Q09 Q01 A11 A M25 A13 Q11 ~500m ~475m M01 M21 A01 A02 A02 A03 M27 A09 M23 M M03 H02 A07 ~250m M15 M19 M05 Tp.75 Rg.6 W4M L19 B02 B01 H01 A05 H05 H13 H15 H17 H21 H27 H31 M13 M07 M09 M11 B11 Christina H07 L02 L03 H03 H04 H11 H29 H35 L11 H19 H L17 B08 B11 J03 J01 J19 L04 H25 L05 B05 H09 J21 L07 ~700m J05 L13 L06 B04 H B07 J09 J L09 L01 L15 B03 J07 J Monday Creek B07 S03 J11 F21 F01 F31 B06 S05 J13 F03 B09 J15 F15 B10 S F29 B13 S09 F17 F07 B12 F27 F S01 F25 F19 F B27 B23 S07 F F23 B19 S13 S17 S19 N23 Kirby N21 F B17 S N09 K01 B25 N19 N11 ~100m N13 K03 N03 N07 ~25m ~950m N05 K05 K07 ~425m ~525m N15 N01 R01 K11 R05 N17 R03 Tp.75 Rg.5 W4M R29 C01 C03 K R07 C23 C ~175m R27 K13 K15 K C07 C27 Tp.76 Rg.5 W4M C05 R09 C19 K17 K19 R C17 U21 ~650m R17 R11 C15 C29 R19 C21 U13 U15 ~525m R15 C C09 U U01 U19 U17 C11 Tp.76 Rg.4 W4M Winefred Tp.75 Rg.4 W4M NON-THERMAL CATEGORY TYPE (1, 2, 3, 4) - EXPECTED SAGD CHAMBER INTERACTION (YEAR) U05 U11 Y01 U R13 U03 U01 U07 R21 ~1000m R23 ~200m ~625m ~600m Y03 Y08 ~450m Y02 Y TITLE APPROVED SUBSURFACE BOX PROPOSED SUBSURFACE BOX NOTES + UNNAMED WATERCOURSE LOCALLY KNOWN AS SAWBONES CREEK REFERENCE ALBERTA DIGITAL BASE DATA OBTAINED FROM ALTALIS LTD. GOVERNMENT OF ALBERTA (ALL RIGHTS RESERVED), AND FROM IHS ENERGY INC. DATUM: NAD 83 PROJECTION: UTM ZONE 12 PROJECT SCALE 1:80,000 GRANDE PRAIRIE RED DEER CALGARY FORT MCMURRAY EDMONTON LETHBRIDGE MEDICINE HAT CHRISTINA LAKE THERMAL PROJECT PHASE H AND EASTERN EXPANSION THERMAL COMPATIBILITY ASSESSMENT RESULTS MAP KILOMETRES PROJECT FILE No. DESIGN ED 14 Mar SCALE AS SHOWN GIS SS 19 Mar CHECK ED 18 Mar REVIEW GEK 18 Mar REV. 0 FIGURE: 6.7-1

29 Cenovus FCCL Ltd Drilling and Completions Mitigation/Remediation Measures Cenovus proposes to monitor, mitigate and/or remediate these 40 non-thermally compatible wells before future thermal operations begin within 600 m of these wells. Monitoring, mitigation and/or remediation plans will be developed on a well by well basis with input from Cenovus, ERCB and the well workover/abandonment service providers contracted by Cenovus. The monitoring, mitigation and/or remediation plan for each well will be finalized pending written approval from the ERCB. Cenovus is not the operator of a majority of the non-thermally compatible wells. Communications with the current operators of the non-thermally compatible wells will occur when planning monitoring, mitigation and/or remediation plans commence Casing Vents Cenovus will continue testing for surface casing vent flows from non-abandoned wells listed in Appendix 1-V1, for which it is the licence holder. These tests will occur within the specified guidelines provided by the ERCB Directive 020 guideline (ERCB 2010e). If an analyzed surface casing vent flow is found to exceed acceptable minimums it will be investigated and remediated as per ERCB guidelines. This monitoring and possible remediation will contribute to maintaining thermal containment of SAGD operations with respect to gas migration Gas Migration The CLTP area does not fall within the required test area for gas migration testing upon abandonment of the well, based on the ERCB Directive 020 guideline. The CLTP plans to do gas migration testing upon abandonment of SAGD well pairs and Wedge Wells.