Book Description

"The Mackenzie Gas Project (MGP) ... has been charged with furthering the designs conceived during the Snowy River Study through the regulatory application stage to transport natural gas and related liquids from the Mackenzie Delta to Alberta. ... The Design Concept Selection, Rev. C, October 9, 2003 considered dense phase, single phase and multi phase. ... Based on the additional technical challenges facing the multiphase concept in a remote environment, the single-phase concept was selected as the lead configuration for MGP. The subsequent Mainline Initial Optimization study, Rev. C July 15, 2003, identified the optimum pressure and diameter for the single-phase concept. ... The study concluded that the 18 MPa pressure range will provide the best coverage of the flow ranges and suggested that the NPS 30 is also the most appropriate pipe size. Since a gas pipeline with a design pressure of 18 MPa using NPS 30 coupled with a 10 MPa, NPS 10 NGL pipeline is the lead configuration based on previous work, it was used as the focal point for this study. The study includes a more thorough examination of the system to transport 34,000 E3m3/d and still be flexible to reduce or expand including evaluation of NPS 28 and NPS 32 systems for comparison. The analysis focused on taking the variable flow rate due to seasonal compression power variation into account and selecting the optimum configuration, including identification of station sites for facility siting work. In addition, sensitivity to the use of intermediate heaters as a means to minimize stranded compression power and confirmation of the technical and cost merits of internal coating were also undertaken for both the gas and NGL pipelines. Of the three pipeline sizes that were considered, the NPS 30 with 5 intermediate stations was identified as the lead configuration for the 34,000 E3m3/d target throughput. Station locations that were identified for site selection work using windows of ±2.5 km are KP 133 (Northern Terminus), KP 358, KP 608.9 (Norman Wells), KP 833, KP 1066, and a heater station is located at KP 1259. This system also allows for the greatest flexibility across the desired operating range (24,000 E3m3/d to 54,000 E3m3/d). The corresponding NGL system should consist of an NPS 10 pipeline with no intermediate stations initially. The assumption that the pipeline should be internally coated was validated by both the 5% flow decrease in throughput if the pipe was not internally coated and the requirement to install two additional compressor stations if left uncoated to meet the target flow rates. The use of heaters to boost system capability using stranded compression power has technical merit but the flow rate increase is insufficient to reduce the number of compressor stations. The unheated system already meets the target flow rates of 34,000 E3m3/d so there is little incentive to pursue this concept. ... The resulting lead configuration from this study, which includes identified initial and expansion station locations, is documented in Revision 1 of ColtKBR's Technical Design Basis, April 16, 2003"--Executive summary.