Entec

Entec provided the planning, design and construction management services required for 3 crossings of the Peace River, Little Cadotte River and Loon River, to facilitate the installation of a 42-inch pipeline. To accomplish this, the hole was reamed to a final diameter of 54 inches. The largest of the 3 crossings, the Peace River, was the longest drill completed in Canada of such large diameter.

A large gravel and cobbles layer was identified on the east side of the Peace River, further increasing the complexity of the project. A comprehensive telescoped surface casing program was devised and resulted in a 60-inch casing at a depth of 88m to bypass the zone. The product pipe was successfully pulled through in April 2009 and the final crossing was successfully completed in February 2010.

A 20-inch pipeline was installed via HDD at four crossings, including North and South Kiskatinaw River, Brassey Creek, and an unnamed creek. The route crossed farmland and natural areas from Fort St. John to just west of Dawson Creek, BC. The subsurface materials were primarily sand and silty clay with trace gravel.

Two product lines (NPS 10 and NPS 4) were installed under the Athabasca River, in the Fox Creek area. This hole boasted a high elevation differential of approximately 85 m and preliminary investigation revealed the potential for aquifers in the area. These issues were handled by the installation of a rotating head on the entry casing, to cap the pressure and manage the large volume of aquifer water influx.

Three parallel steel DPS dual powder abrasion coated replacement lines (36", 30", and 12.75") were installed north of Prince George. All three replacement lines were successfully installed in practically un-drillable conditions, using a very precise drilling program. These installations were previously open cut because of unfavorable subsurface conditions; the formations consisted almost entirely of sand, gravel and cobbles along the entire drill path.

Steel pipe with DPS Dual Powder Abrasion coating was used to maximize the durability of the pipe during the product pull, and a buoyancy program was utilized to reduce pipe stress. Due to the very abrasive nature of the formation, and the very difficult steering in sections, a short coated product pipe test section was pulled on both the 36" and 30" installations to simulate the stresses and wear expected on the pull section. The results of the test pulls indicated that additional reaming passes should be conducted to over-size the holes for safe installation.

Located south of Beaver Lodge in the Elmworth area, near the Alberta – B.C. border, this project consisted of a 1450 m drill from the flood plain, across the Wapiti River and up to the top of the south bank (280 m elevation change) and a second 900 m drill from the flood plain to the top of the north bank (260 m elevation change). The Wapiti River borehole was reamed to 22" to accommodate 14" FBE coated steel pipe while the "Hill Drill" was reamed to 28" to accommodate 14" insulated and cement coated steel pipe (total outside diameter of 18.5"). Upon completion, both boreholes were cemented to prevent aquifer communication along the installed pipes.

This 1150 m crossing was situated near Baton Rouge Louisiana, with a pipe size of NPS 30 inch. The subsurface materials were swelling blue clays and compact sands, with intermittent layers or pockets of gravel. Two significant industry firsts were developed on this project: the utilization of vacuum assisted lift techniques to enhance the removal of sand cuttings from the borehole, and the manufacture and installation of the "Pipe Thruster," which greatly reduces pull forces during installation.

This crossing was located near the Port Mann Bridge in Vancouver BC. The pipe size was NPS 36 inch placed in a 1000 m long 48-inch borehole. The subsurface materials were primarily dense sands with potential gravel pockets.