24 AUGUST 2021 WorldWide Drilling Resource® Pipeline in Peace Compiled by the Editorial Staff of WorldWide Drilling Resource® Located in British Columbia’s Peace River Regional District, the North Montney Mainline (NMML) is providing the critical natural gas transmission infrastructure required to connect producers and downstream markets throughout Canada and the United States. The pipeline connects the liquids-rich Montney Formation, west of the Alaska Highway, to the existing NGTL (Nova Gas Transmission Limited) infrastructure, owned and operated by TC Energy. The NMML project consisted of a 128-mile, 42-inch pipeline, two compressor stations, and 11 meter stations. Construction began in mid-2018, with facilities phased into service last year. The Peace River crossing of the pipeline was particularly difficult, so horizontal directional drilling (HDD) contractor Direct Horizontal Drilling, based in Edmonton, Alberta, was called on to tackle this part of the project. The intersect method was used for a 3642-foot section. Before the pilot bore could be drilled, crews had to install 84-inch steel casing at the entry and exit pits due to the high concentration of gravel on either side of the river to allow the drill pipe and product pipe to be installed in a stable borehole. Boring under the river was through mediumstrength bedrock. Using a pneumatic hammer, crews drove in the casing into the gravel on the exit side, going to a depth of 164 feet at a 15-degree angle. Then crews slid in 76-inch casing to a depth of 207 feet, finishing the installation with 60-inch casing at 292 feet. The entry side just needed the 76-inch casing, going to a depth of 82 feet. The casing allowed operators to isolate the gravel so they could drill without being impeded by anything. With the casing installed, the crews turned to boring the pilot hole. They mobilized two rigs, a 1.1-million-pound rig on the entry side and a 160,000-pound rig on the exit side. Both rigs were customized by Direct Horizontal Drilling to meet the needs of the tough Canadian winter drilling season - skid-mounted and highly mobile to operate in the cold. The intersect of the 12¼-inch pilot bore took about two weeks to complete. The back reaming was completed in three passes, using a 30-inch, then a 42-inch, and finally, a 54-inch reamer. Each reaming pass took approximately two weeks to complete. The rigs were both tied to the drill pipe so the rotary from both could turn the larger hole openers. Both rigs were turning the string of pipe at the same time. The 42-inch steel gas line was laid out on the exit side and welded together while drilling was taking place. This pipe, with a total weight of two million pounds, was held up during pullback by 12 cranes in an arch to rope the pipeline into the same angle for the exit hole. Using a maximum pullforce of 200,000 pounds, this took about 16 hours to complete. As part of the pullback, the crew ran buoyancy control inside the 42-inch product pipe to keep it from floating to the top or riding the bottom of the hole. Once the pullback was finished, they pulled out the 32-inch and 4-inch lines, as well as removed the casing. Dave Fisher, business development for Direct Horizontal Drilling said, “Overall, it was a very difficult project, but with the proper planning, it was successful for us and TransCanada [Pipelines]. It is the largest diameter pipe over that length installed [using directional drilling] in Canada.” Photo courtesy of Direct Horizontal Drilling. Photo courtesy of TC Energy. DIR
RkJQdWJsaXNoZXIy NDk4Mzk=