Attachment 6. HDD Feasibility Report

Transcription

1 May 2016

2 May 2016

3 May 2016 Page 1 of 21

4 The Pipeline Project TABLE OF CONTENTS 1 Introduction HDD Crossings Design Parameters Tributary to Simonette River Crossing Watercourse Description Horizontal Directional Drill Alignment Laydown Area Geotechnical Review Design Summary Specific Construction Risks Contingency Crossing Method Ante Creek Watercourse Crossing Watercourse Description Horizontal Directional Drill Alignment Laydown Area Geotechnical Review Design Summary Specific Construction Risks Contingency Crossing Method Summary of HDD Risk Assessments Summary of the HDD Schedules Drilling Fluid Disposal Water Supply Recommendations Conclusions Reference Documents HDD Design Drawings Appendix A Stress Summary Appendix B Annular Pressure Charts Page 2 of 22 Project #: 1590 May 2016 Page 2 of 21

5 The Pipeline Project 1 INTRODUCTION NOVA Gas Transmission Ltd. (NGTL), a wholly owned subsidiary of TransCanada Pipelines Limited, is proposing to construct, own and operate the Pipeline Project to safely delivery natural gas to the existing NGTL system in Alberta. The Project, located approximately 119 km south east of Grande Prairie, Alberta, consists of approximately 21 km of mm (NPS 8), mm (NPS 6), and mm (NPS 4) outside diameter pipe. The pipeline will be constructed in two new sections (Southern and Northern sections) which will tie-in to and utilize the existing NPS 6 Sturgeon Lake South Lateral to transport gas between the two sections. The Southern Section of the Project will begin from a tie-in point on the existing NPS 36 Western Alberta System Mainline Extension (WASME) in SE W5M and will consist of NPS 8 pipe for approximately 4 km, then reduce to NPS 6 pipe to continue for approximately 11 km and tie-in to the SLSL in NE W5M. The Northern Section will branch off the Sturgeon Lake South Lateral in SE W5M with NPS 6 pipe for approximately 6 km to tie-in to NPS 8 Boulder Creek Lateral (BCL) in SE W5M, and continue for approximately 100 m of NPS 4 pipe to tie-in to NPS 4 Calais Extension in NE W5M. Construction for the two sections of the pipeline will be concurrent. Within the scope of the Project, two watercourses have been determined where NGTL is proposing to utilize the Horizontal Directional Drill (HDD) methodology for the pipeline installations. This report is provided as a feasibility assessment of site conditions, incorporating the provided draft geotechnical information and a geometric review of the proposed HDD alignment and design. The proposed HDD design drawings and this feasibility report will be reviewed and revised upon receipt of the final geotechnical report. 2 HDD CROSSINGS This report will assess the feasibility of the following HDD installations: Tributary to Simonette River Watercourse Crossing (SW ¼ W5M) NPS 8 Pipe installation Ante Creek Watercourse Crossing (SW ¼ W5M) NPS 6 Pipe installation 3 DESIGN PARAMETERS The HDD crossings are designed to incorporate the geotechnical information provided, Pipeline Research Council International (PRCI) PR guidelines, access specifications, above ground/buried facilities in the area, watercourse geometric parameters and space limitations. The geotechnical conditions at the site were considered in an effort to design the drill for progression primarily through formations that are favorable for horizontal directional drills, methodology of construction, industry practices, environmental risks, and engineering tolerances. Page 3 of 21 Project #: 1590 May 2016 Page 3 of 21

6 The Pipeline Project PRCI design guidelines (PR , Updated in 2008 to PR ), as suggested in CSA Z662, were utilized to model the bending, hoop, and tensile stresses for the installation, and operating conditions imposed after installation. The calculations consider the pipe diameter, wall thickness, grade, depth and geometric design of the crossing. The watercourse crossings were designed by completing an annular pressure analysis to minimize the risk of hydraulic fracture to the water body during the drilling process. Annular pressure calculations model the potential fracture pressure of the overburden formation versus the expected downhole pressures created during the pilot-hole phase. Space limitations associated with the Right of Way (ROW), points of inflection (PI) and achievable temporary workspace (TWS) were also considered. 4 TRIBUTARY TO SIMONETTE RIVER CROSSING 4.1 Watercourse Description The Tributary to Simonette River watercourse is an approximately 150 m wide wetland area with a small channel meandering towards the Simonette River. The extents of the watercourse are not clearly defined. The immediate area is expected to be wet and marshy. Beaver dam development has also been observed at the crossing location. 4.2 Horizontal Directional Drill Alignment The proposed HDD crossing utilizes the existing ARC ROW in a southwest to northeast alignment. The entry location is approximately 140 m southwest of the tributary watercourse while the exit location is approximately 280 m northeast. The drill passes 32 m below the centerline of the waterbody. Temporary workspace (TWS) is required at both the entry and exit areas. The TWS dimensions are 50 m x 50 m on entry side and 30 m x 30 m on exit side. The proposed TWS is expected to be sufficient for the anticipated construction spread. 4.3 Laydown Area The design proposes that the product line be laid out in one section on the northeast upland of the crossing along the ROW and proposed TWS. The proposed workspace on the northeast upland is 15 m x 450 m for the pullback operation. It is expected that a minimum of five (5) side booms will be required for the safe pull-back installation of the product pipe. 4.4 Geotechnical Review Three (3) boreholes were completed along the proposed crossing alignment as part of a geotechnical investigation completed by Stantec in March, At the time of the preparation of this report and Issued for Review (IFR) HDD design drawings, only the draft geotechnical report and borehole logs (BH02 through BH04) were made available for use in the design. At the location of BH02, near the planned entry location, approximately 6 m of clay was encountered beneath a thin layer of topsoil and sand, underlain by clay (till) which extended Page 4 of 21 Project #: 1590 May 2016 Page 4 of 21

7 The Pipeline Project beyond the 8 m depth of investigation. A 1.3 m thick zone within the clay (till) contained frequent coal pieces/ rafts, at a depth of 6.3 m. Similar stratigraphy was reported at the location of BH03, with a thin layer of topsoil, 0.7 m of sand and 2 m of clay overlying clay (till), which extended to the 20.2 m depth of investigation. A 0.5 m thick gravel deposit was reported within the clay (till) at a depth of 9.8 m. At the location of BH04, near the planned exit area on the northeast approach, 5 m of clay (till) was underlain by sand, which extended beyond the 12.7 m depth of investigation. The near-surface clay overlying the clay (till) in BH02 was described as firm, low plastic (high plastic below 1.4 m depth), sandy, with trace gravel below 4.5 m depth. The near-surface clay in BH03 was described as firm to stiff, low to high plastic, with sand. The clay (till) was generally described as low to high plastic and firm to very stiff, with trace amounts of gravel, sand and bedrock fragments. The sand, encountered at depth in BH04 was reported to be poorly graded and compact to dense. 4.5 Design Summary The proposed HDD has been designed by incorporating all specified design considerations including supplied topographical and geotechnical information, as well as installation and operating pipe stresses. The entry and exit angles were chosen based on stress analysis, materials, bending restrictions, the support of the pullback section, and to meet the workspace requirements. The drill profile includes an entry angle of 18 degrees on the southwest side of the watercourse. The angle is achievable by most stock drilling rigs that are sized appropriately for this crossing. The entry tangent is 52 m long and transitions to a 126 m long, 400 m radius build section. The designed drill path follows a horizontal tangent for 10 m with 34 m of vertical cover under the surface. The drill path continues to a 112 m long, 400 m radius build arc, and finally on to the exit tangent. The exit tangent is 124 m long and exits the ground surface at a 16 degree angle. This HDD is designed to be completed with the drill and pull method, in which the contractor will install the pipeline after the pilot hole is drilled. With this method, the pilot hole is the final borehole and no ream passes are required. Annular pressure was modeled to simulate the downhole pressure during the pilot hole and it is shown in Appendix B. The annular pressure values are compared to the expected fracture pressure of the geological formation above the drill path. According to the annular pressure chart, the expected overburden fracture pressure is larger than the expected drilling pressures for the entirety of the drill path design, indicating a low risk of hydraulic fracture to surface. Similar to any theoretical modeling, the annular pressure analysis is a tool to better understand the fracturing mechanism during HDD. Based on this model, drilling pressures exceeding the overburden fracture pressure don t necessarily indicate a fracture will occur, but rather higher risk that a hydraulic fracture may occur in those areas. For this particular crossing, the operating stresses govern the design of the pipe, and not the installation stresses. Calculations for the crossing suggest that the pull force will be approximately 25,000 lbs. (without buoyancy control) for the NPS 8 installation. Calculations Page 5 of 21 Project #: 1590 May 2016 Page 5 of 21

8 The Pipeline Project carried out by CCI indicate that a wall thickness of 8.2 mm and Gr. 359 steel is suitable for this crossing, based upon the operating conditions supplied. A summary of the stress analysis calculations is attached in Appendix A. The following is a summary of the design of the Tributary to Simonette River HDD crossing: Pipe Specifications mm OD, 8.2 mm W.T., GR. 359 Preliminary Coating Selection FBE System 2B Entry Angle (Degrees) 18 Exit Angle (Degrees) 16 Radius of Curvature (m) 400 Length (m) 424 Borehole Size (m) Design Depth Under Watercourse Thalweg (m) 32 Design Pressure (kpa) 7,850 Installation Temperature ( C) -10 Design Operating Temperature ( C) 49 Design Factor 0.8 Location Factor 1.0 Pullback Force (with safety factor, lbs.) 25,000 (without buoyancy) Maximum Operating Stress (% of Allowable) 82.3 Maximum Installation Stress (% of Allowable) 24 Drilling Tolerances (R.O.C. per length) 10m-125 m / 30m-200 m / 100m-360 m Table 1: Design Summary for Tributary to Simonette River HDD Crossing 4.6 Specific Construction Risks The following are the main construction risks identified, based on the risk assessment conducted by CCI and previous experience. Also identified are the main mitigation strategies developed to minimize the challenges that may arise during construction. Page 6 of 21 Project #: 1590 May 2016 Page 6 of 21

9 The Pipeline Project Zone 1: 0-70 m MD (Measured Depth) The presence of medium to high plastic clay/clay till allows some potential to form mud rings through cutting adhesion. Mud rings in combination with borehole squeezing can block off the hole around the drill stem causing poor cutting clearance and annular pressure spikes. A proper drilling fluid management plan by the HDD contractor should be utilized to minimize the formation of mud rings. If issues still arise, mechanical swabbing may be required. It is expected that the HDD borehole will penetrate through clay (till). Although no cobbles were observed during testing, clay (till), by definition, comprises a heterogeneous mixture of all soil types including a random distribution of cobbles and boulders. The possible presence of cobble and/or boulder sized material along any drill path through the clay (till) should be expected. Properly sized equipment should be used to help minimize deflection while drilling the pilot hole. If encountered, coal seams may cause loss of circulation and be responsible for some fluid loss into the formation. Drilling fluid parameters and volume shall be monitored to ensure cuttings are removed from the borehole and any loss of fluids is quickly identified. Frac walks shall be in place throughout the drill at a regular scheduled interval to be determined by the project. Once a loss in a fractured zone is identified, the contractor should stop, place an approved plug (bentonite, magma fibre, hole plug) prior to continuing. This plug can be squeezed into the formation on pilot hole and can be effective if applied correctly. Zone 2: m MD The drill path passes below the depth of geotechnical investigation. Formation properties may be different from what was encountered in the geotechnical investigation. Continuous monitoring of drill performance, including annular pressure and cuttings return, should be maintained. The Contractor shall attempt to complete the crossing by utilizing the mud motor downhole tooling to mitigate any possible bedrock conditions. Fracture to waterbody. The drill path has been designed to minimize the risk of fracture to waterbody. The contractor shall closely monitor the annular pressure to ensure it remains within the designed pressure curve. If the annular pressure exceeds the theoretical model, the contractor shall trip out the drill string to reduce the pressure and ensure no fractures occur. Page 7 of 21 Project #: 1590 May 2016 Page 7 of 21

10 The Pipeline Project Zone 3: m MD There is a potential risk for sloughing and collapse of the borehole due to the sand above entry elevation. It is expected that drilling fluid flow rates will be minimized through this formation as the pilot hole exits to surface. Zone 4: Pull-back The possible presence of gravel and cobbles along with the unknown geotechnical condition suggests that the pipeline may become damaged during pull-back. The pipe coating for this crossing will be Fusion Bond Epoxy (FBE) System 2B. It is expected to provide suitable protection from corrosion, moisture, abrasion and impact damage. Extra care should be taken to ensure a clean and open hole prior to pull-back. The borehole should be proven with a wiper trip prior to pipe pull. Additional wiper passes may be required. 4.7 Contingency Crossing Method In the event that the proposed HDD crossing becomes infeasible, due to unforeseen conditions, the installation will be completed by the open-cut methodology. The burial depth and length of the crossing will be reviewed when the hydrological scour assessment and flood plain extents have been modeled. Upon receipt of the hydrological data, a plan shall be developed to isolate the watercourse to install the product pipe at the burial depth. Page 8 of 21 Project #: 1590 May 2016 Page 8 of 21

11 The Pipeline Project 5 ANTE CREEK WATERCOURSE CROSSING 5.1 Watercourse Description Ante creek generally meanders trending in a southeast to northwest direction, eventually flowing into the Simonette River. At the crossing location, the creek is located at the bottom of a 20 m deep and 350 m wide valley, crest to crest. The Ante creek channel is approximately 10 m wide and 2 to 3 m deep at the crossing location. 5.2 Horizontal Directional Drill Alignment The proposed HDD crossing of the Ante Creek follows a southwest to northeast alignment crossing the creek between meander bends. The entry location is approximately 350 m southwest of the watercourse while the exit location is located 275 m northeast of the watercourse. The drill passes 48.8 m below the centerline of Ante Creek. Temporary workspace (TWS) is required at both the entry and exit areas. The TWS dimensions are 46 m x 46 m for entry pad, and 33 m x 41 m for exit pad. The TWS shown is expected to be sufficient for the anticipated construction spread. 5.3 Laydown Area The design proposes that the product line be laid out in one section on the northeast of the crossing along the proposed TWS. A 20 m x 150 m TWS is required in addition to the available 20 m x 462 m workspace for the pullback operation. A 30 m x 30 m TWS for turnaround is also proposed at the northeast end of the pullback section. It is expected that a minimum of five (5) side booms will be required for the safe pull-back installation of the product pipe. 5.4 Geotechnical Review Four (4) boreholes were completed along the proposed crossing alignment as part of a geotechnical investigation completed by Stantec in February, At the time of the preparation of this report and IFR HDD design drawings, only the draft geotechnical report and borehole logs (BH07 through BH10) were made available for use in HDD design. Similar conditions were reported at the location of BH07, BH09 and BH10, located on the west and east approaches, respectively. Beneath a thin layer of topsoil, 3.3 to 6.6 m of clay was shown to overlie clay (till), which extended beyond the 15.7 to 30.5 m depths of investigation at these locations. BH08, drilled and sampled near the creek within the floodplain area was reported to encounter 1.8 m of sand underlain by 22.6 m of clay (till), which was underlain by a variable sequence of interbedded clay and sand extending beyond the 37.1 m depth of investigation. A layer of 1.5 m thick silt and a 0.5 m thick sand deposit were also encountered within the clay (till), at depths of 7.3 m and 18.5 m respectively. The sand deposits at depth, interbedded with the clay, ranged in thickness from 1.5 to 1.8 m. The near-surface clay overlying the clay (till) in BH07, BH09 and BH10 was generally described as low to high plastic and firm to stiff (soft to firm in BH10), with trace amounts of sand and occasional sand seams. The clay (till), where encountered, was described as low to high plastic and firm to very stiff, with trace of sand and gravel, and occasional sand seams/layers. The Page 9 of 21 Project #: 1590 May 2016 Page 9 of 21

12 The Pipeline Project interbedded clay and sand layers encountered at depth in BH08 underlying the clay (till) were stiff to hard and compact to dense, respectively. It is important to note that an artesian groundwater condition encountered at approximately 36 m depth, at the BH08 location. An artesian head pressure of 1.5 to 1.8 m was observed by the field personnel. The head pressure of the artesian conditions is less than entry elevation and is not expected to flow to surface. 5.5 Design Summary The proposed HDD has been designed by incorporating all specified design considerations including supplied topographical and geotechnical information, as well as installation and operating pipe stresses. The entry and exit angles were chosen based on stress analysis, materials, bending restrictions, the support of the pullback section, and to meet the workspace requirements. The drill profile includes an entry angle of 18 degrees on the southwest side of the watercourse. This angle is achievable by most stock drilling rigs that are sized appropriately for the crossing. The entry tangent is 165 m long, transitioning to a 126 m long arc, following a 400 m radius. The designed drill path follows a horizontal tangent for 30 m with 49 m of vertical cover under the surface. The drill path continues to an exit arc 112 m long designed with a 400 m radius, and moves on to the exit tangent. The exit tangent is 205 m long and exits the ground surface at a 16 degree angle. This HDD is designed to be completed with the drill and pull method, in which the contractor will install the pipeline after the pilot hole is drilled. With this method, the pilot hole is the final borehole and no ream passes are required. Annular pressure was modeled to simulate the downhole pressure during the pilot hole and is shown in Appendix B. The annular pressure values are compared to the expected fracture pressure of the geological formation above the drill path. According to the annular pressure chart, the expected overburden fracture pressure is larger than the expected drilling pressures for the majority of the drill path design, indicating a low risk of hydraulic fracture to surface. Close to exit side, the annular pressure exceeds the overburden fracture pressure. Although fracture to surface near the exit point is not uncommon in HDD operations, care shall be taken to minimize the risk of fracture by excavation of an exit pit and utilizing minimal flow rate for the final 50 metres of the drill path. Similar to any theoretical modeling, annular pressure analysis is a tool to better understand the fracturing mechanism during HDD. Based on this model, drilling pressures exceeding the overburden fracture pressure don t necessarily indicate a fracture will occur, but rather higher risk that a hydraulic fracture may occur in those areas. For this particular crossing, the operating stresses govern the design of the pipe, and not the installation stresses. Calculations for the crossing suggest that the pull force will be approximately 28,000 lbs. (without buoyancy control) for the NPS 6 installation. Calculations carried out by CCI indicate that a wall thickness of 7.1 mm and Gr. 359 steel is suitable for this crossing, based upon the operating conditions supplied. A summary of stress analysis calculations is attached in Appendix A. The following is a summary of the design of the Ante Creek Watercourse HDD crossing: Page 10 of 21 Project #: 1590 May 2016 Page 10 of 21

13 The Pipeline Project Pipe Specifications mm OD, 7.1 mm W.T., GR. 359 Preliminary Coating Selection FBE System 2B Entry Angle (Degrees) 18 Exit Angle (Degrees) 16 Radius of Curvature (m) 400 Length (m) 638 Borehole Size (m) Design Depth Under Watercourse Centerline (m) 48.8 Design Pressure (kpa) 7,850 Installation Temperature ( C) -10 Design Operating Temperature ( C) 49 Design Factor 0.8 Location Factor 1.0 Pullback Force (with safety factor, lbs.) 28,000 (without buoyancy) Maximum Operating Stress (% of Allowable) 75.8 Maximum Installation Stress (% of Allowable) 23 Drilling Tolerances (R.O.C. per length) 5.6 Specific Construction Risks 10m-100 m / 30m-150 m / 100m-360 m Table 2: Design Summary for Ante Creek HDD Crossing The following are the main construction risks identified, based on the risk assessment conducted by CCI and previous experience. Also identified are the main mitigation strategies developed to minimize the challenges that may arise during construction. Zone 1: m MD (Measured Depth) The presence of medium to high plastic clay/clay (till) allows some potential to form mud rings through cutting adhesion. Mud rings in combination with borehole Page 11 of 21 Project #: 1590 May 2016 Page 11 of 21

14 The Pipeline Project squeezing can block off the hole around the drill stem causing poor cutting clearance and annular pressure spikes. A proper drilling fluid management plan by the HDD contractor should be utilized to minimize the formation of mud rings. If issues are still experienced, mechanical swabbing may be required. It is expected that the HDD borehole will penetrate through clay (till). Although no cobbles were observed during testing, clay (till), by definition, comprises a heterogeneous mixture of all soil types including a random distribution of cobbles and boulders. The possible presence of cobble and/or boulder sized material along any drill path through the clay (till) should be expected. Properly sized equipment should be used to help minimize deflection while drilling the pilot hole. Zone 2: m MD Artesian aquifers were encountered at BH08 with head pressure estimated about 1.5 to 1.8 m above the ground level. This can lead to fluid control issues caused by water ingress such as dilution of the drilling fluid and increased drilling fluid returns. Drilling fluid parameters and volume will be monitored to ensure drilling fluid dilution is managed. Temporary onsite storage should be available and proper drilling fluid disposal plans shall be in place. There is a potential risk for sloughing and collapse of the borehole due to the sand zones. This risk can be mitigated in a number of ways: Utilizing an Engineered Drilling Fluid Plan (EDFP) that includes a fluid loss additive such as a Polyanionic Cellulose Additives (PAC) will aid in providing a filter cake on the borehole to stabilize the formation when circulating. Drilling fluid parameters will be optimized for maximum cutting transportation. The parameters will be established based on the contractor s EDFP. Additional tripping (pulling the drill string out of the borehole and then running it back in) will be necessary to mechanically remove cuttings from the borehole. The number of trips required will be based on the borehole conditions. The presence of medium to high plastic clay/clay till allows some potential to form mud rings through cutting adhesion. Mud rings in combination with borehole squeezing can block off the hole around the drill stem causing poor cutting clearance and pressure spikes. Page 12 of 21 Project #: 1590 May 2016 Page 12 of 21

15 The Pipeline Project A proper drilling fluid management plan by the HDD contractor should be utilized to minimize the formation of mud rings. If issues still arise, mechanical swabbing may be required. Zone 3: m MD The drill path passes below the depth of geotechnical investigation. Formation strength and properties could differ from what was encountered in the geotechnical investigation. Continuous monitoring of drill performance, including annular pressure and cuttings return, should be maintained. The Contractor shall attempt to complete the crossing by utilizing the mud motor downhole tooling to mitigate any possible bedrock conditions. Fracture to waterbody The drill path has been designed to minimize the risk of fracture to waterbody. The contractor shall closely monitor the annular pressure to ensure it remains within the designed pressure curve. If the annular pressure exceeds the theoretical model, the contractor shall trip out the drill string to reduce the pressure and ensure no fractures occur. Zone 4: m MD The risks and mitigation strategies for this zone are similar to zone 1: m. Zone 5: Pull-back The possible presence of gravel and cobbles along with the unknown geotechnical condition suggests that the pipeline may become damaged during pull-back. The pipe coating for this crossing will be Fusion Bond Epoxy (FBE) System 2B. It is expected to provide suitable protection from corrosion, moisture, abrasion and impact damage. Extra care should be taken to ensure a clean and open hole prior to pull-back. The borehole should be proven with a wiper trip prior to pipe pull. Additional wiper passes may be required. 5.7 Contingency Crossing Method In the event that the proposed HDD crossing becomes infeasible, due to unforeseen conditions, the installation will be completed by the open-cut methodology. The burial depth and length of the crossing will be reviewed when the hydrological scour assessment and flood plain extents have been modeled. Upon receipt of the hydrological data, a plan shall be developed to isolate the watercourse to install the product pipe at the burial depth. Page 13 of 21 Project #: 1590 May 2016 Page 13 of 21

16 The Pipeline Project 6 SUMMARY OF HDD RISK ASSESSMENTS Detailed risk assessments of the Tributary to Simonette River Watercourse and Ante Creek crossings have been completed, summarizing the possible construction issues that may be encountered. As discussed in sections 4.6 and 5.6, risks and mitigations have been identified for these HDD installations and, if mitigated properly, the risks are manageable. 7 SUMMARY OF THE HDD SCHEDULES Overall Schedule Task Tributary Ante Creek Mob./Rig In 1 Day 1 Day Pilot Hole 4 Days 6 Days Swab and Pullback 1 Day 1 Day Demob./Rig Out 1 Day 1 Day Total 7 Days 9 Days Table 3: Overall Schedule Assumptions: The schedule is based on 7 working days a week. The schedule is based on working 24 hours per day (2 shifts per day). Standard production rates with minimal fractures. Drill and pull methodology. 8 DRILLING FLUID DISPOSAL The highland on northeast side of the Tributary to Simonette Rver crossing and highlands above the valley on either side of the Ante Creek crossing may be feasible for the disposal of drilling fluids, where land spraying would be applicable on existing ROW or TWS. Land owner consent and further testing of the ground conditions may be required to ensure the land will be acceptable for land spraying. Additionally, sumps may be required in conjunction with land spraying for disposal. Suitable locations for sump development should be investigated prior to construction. Page 14 of 21 Project #: 1590 May 2016 Page 14 of 21

17 The Pipeline Project Crossing Name Fluid Disposal (m 3 ) Solid Disposal (m 3 ) Tributary to Simonette River Ante Creek Table 4: Estimated Drilling Fluid Disposal Volume Assumptions: The contractor provides adequate recycling systems. Assumes minimal loss of circulation to provide a conservative disposal estimate. Drill and pull methodology. 9 WATER SUPPLY It may be possible that water for drilling purposes may be withdrawn from the watercourses. Alternate sources, such as nearby municipalities, should be investigated and Temporary Diversion Licenses obtained prior to commencement of construction. Crossing Name Water Volume (m 3 ) Tributary to Simonette River 163 Assumptions: Ante Creek 161 Table 5: Estimated Water Supply Volume The volume is based on the estimated initial water requirements, dilution rates, HDD schedule, and the final borehole size. The water required for the pretest of the pipe sections has not been included in these estimates. 10 RECOMMENDATIONS The following recommendations outline the main action items that should be completed in order to ensure a smooth progression of the project into the construction phase: a) The HDD design shall be reviewed and incorporate any new data from the final geotechnical report, once received. Page 15 of 21 Project #: 1590 May 2016 Page 15 of 21

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19 The Pipeline Project 12 REFERENCE DOCUMENTS HDD DESIGN DRAWINGS This report is based on the following HDD design drawings. Crossing Type Drawing Number Sheet Tributary to Simonette River HDD 1559-EG-01-A 1 of 1 Ante Creek HDD 1559-EG-02-A 1 of 1 Page 17 of 21 Project #: 1590 May 2016 Page 17 of 21

20 The Pipeline Project APPENDIX A STRESS SUMMARY Tributary to Simonette River HDD Crossing Owner: TCPL Project: BOULDER CREEK Date: 03/16/2016 Calculation Description: Stress Assessment NPS 8 HDD Applicable Crossings: TRIBUTARY TO SIMONETTE RIVER Completed By: SW Reviewed By: JT Pipe Information Design Criteria Crossing Characteristics Pipe Pipe Max. Operating Installation Design Maximum Depth From HDD Diameter W.T. Pipe MOP Temperature Temperature Radius Entry Location Length (mm) (mm) Grade (kpa) ( Celsius) ( Celsius) (m) (m) (m) , The pipe section installated stresses are modelled in 5 sections (exit tangent (5), exit arc (4), bottom tangent (3), entry arc (2), entry tangent (1)) incorporating effects of buoyancy, soil friction, curvature, fluidic drag and pipe weight. The calculated stresses are evaluated using the AGA method (PRCI). Operating stresses incorporate hoop, bending, tensile, and thermal expansion. Variable Definitions: SMYS D E - Specified Minimum Yield Strength - Outer Diameter of Product Pipe - Young's Modulus (Steel) t - Wall Thickness of Product Pipe 0 Tensile Stress: Allowable Tensile Stress % of Allowable MPa F(t) = (0.9)* SMYS 2.9% MPa F(t) = MPa 3.6% MPa 3.6% MPa 4.1% MPa 4.1% Bending Stress: Allowable Bending Stress % of Allowable MPa F(b) = 0.75 x SMYS 0.3% MPa F(b) = MPa 20.3% MPa 0.3% MPa 20.3% MPa 0.3% Hoop Stress: Allowable Hoop Stress % of Allowable MPa F(h)= [0.88 x E x (t/d)^2] / % MPa F(h) = MPa 5.3% MPa 5.3% MPa 5.3% MPa 2.6% Operating Stresses: Allowable Shear Stress % of Allowable MPa F(v) = 45% of SMYS 65.6% MPa F(v) = MPa 82.3% MPa 65.6% MPa 82.3% MPa 65.6% Combined Stress (Tensile and Bending) % of Allowable Unity Check (<1) 3% % % % % Combined Stress (Tensile, Bending, and Hoop) % of Allowable Unity Check (<1) 0% % % % % Estimated PullForce (without Buoyancy Control) 16,261 lbs 24,391 lbs (including 1.5x Safety Factor) Page 18 of 21 Project #: 1590 May 2016 Page 18 of 21

21 The Pipeline Project Ante Creek HDD Crossing Owner: TCPL Project: BOULDER CREEK Date: 03/16/2016 Calculation Description: Stress Assessment NPS 8 HDD Applicable Crossings: ANTE CREEK Completed By: SW Reviewed By: JT Pipe Information Design Criteria Crossing Characteristics Pipe Pipe Max. Operating Installation Design Maximum Depth From HDD Diameter W.T. Pipe MOP Temperature Temperature Radius Entry Location Length (mm) (mm) Grade (kpa) ( Celsius) ( Celsius) (m) (m) (m) , The pipe section installated stresses are modelled in 5 sections (exit tangent (5), exit arc (4), bottom tangent (3), entry arc (2), entry tangent (1)) incorporating effects of buoyancy, soil friction, curvature, fluidic drag and pipe weight. The calculated stresses are evaluated using the AGA method (PRCI). Operating stresses incorporate hoop, bending, tensile, and thermal expansion. Variable Definitions: SMYS D E - Specified Minimum Yield Strength - Outer Diameter of Product Pipe - Young's Modulus (Steel) t - Wall Thickness of Product Pipe 0 Tensile Stress: Allowable Tensile Stress % of Allowable MPa F(t) = (0.9)* SMYS 6.0% MPa F(t) = MPa 6.6% MPa 6.6% MPa 7.1% MPa 6.8% Bending Stress: Allowable Bending Stress % of Allowable MPa F(b) = 0.75 x SMYS 0.2% MPa F(b) = MPa 15.6% MPa 0.2% MPa 15.6% MPa 0.2% Hoop Stress: Allowable Hoop Stress % of Allowable MPa F(h)= [0.88 x E x (t/d)^2] / % MPa F(h) = MPa 8.3% MPa 8.3% MPa 8.3% MPa 6.0% Operating Stresses: Allowable Shear Stress % of Allowable MPa F(v) = 45% of SMYS 63.0% MPa F(v) = MPa 75.8% MPa 63.0% MPa 75.8% MPa 63.0% Combined Stress (Tensile and Bending) % of Allowable Unity Check (<1) 6% % % % % Combined Stress (Tensile, Bending, and Hoop) % of Allowable Unity Check (<1) 1% % % % % Estimated PullForce (without Buoyancy Control) 18,644 lbs 27,966 lbs (including 1.5x Safety Factor) Page 19 of 21 Project #: 1590 May 2016 Page 19 of 21

22 The Pipeline Project APPENDIX B ANNULAR PRESSURE CHARTS Tributary to Simonette River HDD Crossing Page 20 of 21 Project #: 1590 May 2016 Page 20 of 21

23 The Pipeline Project Ante Creek HDD Crossing Page 21 of 21 Project #: 1590 May 2016 Page 21 of 21