Case Studies

Project Type
OIL & GAS PIPELINE
Location
BRITISH COLUMBIA, CANADA
Length / Hole Diameter
1,189 m (3,901 ft)/ 914 mm (36 in)
Divisions
The Crossing Company, The Tunneling Company

BUCKINGHORSE RIVER

ENVIRONMENTALLY SENSITIVE CROSSING

Project Summary

In Canada, oil and gas pipelines are regulated, planned and built to the highest standards in the world. In environmentally sensitive areas, companies work with all stakeholders to mitigate risks and protect against spills.

The Buckinghorse River HDD was a large intersect project, completed over 108 days in a remote area of northern British Columbia. One 203 mm (8 in) line and two 254 mm (10 in) lines were installed. To address environmental concerns, the project design called for the pipeline to be placed at a depth of 160 m (525 ft). This created a 114 m (374 ft) buffer (or “overburden”) between the pipeline and the riverbed. The design also required extensive casing at the entry and exit location.

The Crossing Company was able to maximize efficiency and minimize costs by collaborating with The Tunneling Company (TTC) to install a portion of the surface casing on the entry location.

Key Challenges

This project was challenging on many levels. Rigs were placed on both the entry and exit locations to drill the pilot hole, using an intersect method. Due to the depth of the bore profile, careful planning and technical expertise were required to execute the intersect. To add to the complexity of the crossing, the entry and exit angles were extremely steep (26° and 18° respectively).

The Tunneling Company installed 78.05 m (256 ft) of 1,372 mm (54 in) surface casing at entry. The Crossing Company then took over, completing the 1,372 mm surface casing install to 90.5 m (297 ft). Then a proprietary pre-reaming tool (we call “The Durango”) was used to telescope 1,219 mm (48 in) surface casing the final distance to a depth of 102 m (335 ft). The exit side rig installed 47 m (154 ft) of 1,219 mm (4 ft) casing.

On top of this, sound attenuation was required at the exit location, which was in close proximity to a local campground.

This project exemplifies the Crossing Group’s commitment of going to greater lengths (and depths) to ensure pipelines remain the safest and most economical way to transport the petroleum products we all rely upon.

Services Provided

HORIZONTAL DIRECTIONAL DRILLING (HDD), SURFACE CASING

TUNNEL BORING / PIPE JACKING

Tunnel Boring and Pipe Jacking Systems are used to hydraulically install underground pipelines up to 4.2 m (168 in) in OD range within strict alignment and grade tolerances. The likelihood of settling or sloughing is very low. Wheel machines are equipped with various cutter heads and sand shelves. A closed-face attachment is available for boring in unstable ground conditions. This versatile system can be easily adapted to work with any jacking pipe, in any pipe joint length. It can accommodate a wide range of pipe diameters.

Tunnel Boring Machines are used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They can bore through hard rock, sand, and almost anything in between. Tunnel diameters can range from 1 m and exceed 15 m (3 ft to 49 ft).

The Crossing Group - The Tunneling Company - Tunnel Boring - Pipe Jacking - Trenchless Construction - Tunneling - Augering, Boring & Pipe Ramming

SLIP BORING

A boring technique commonly used for installing oil & gas pipelines ranging from 51 mm to 1067 mm (2 in to 42 in) in diameter without leaving casing in the ground. Product pipe is welded to steel casings and either pushed or pulled through the ground in sections. The casing is cut off and removed, leaving just the product pipe. Maximum installation length is 150 m (492 ft).

The Crossing Group - The Tunneling Company - Slip Boring - Trenchless Construction - Tunneling - Augering, Boring & Pipe Ramming

DOWN THE HOLE HAMMER

A pneumatic hammer is attached to the inside edge of the casing. The front of the DTH breaks cobles, boulders and even solid rock into small pebbles or dust. The spoil makes its way through the hammer and into the casing, where it is removed by airway augers.

The Crossing Group - The Tunneling Company - Down The Hole Hammer - DTH - Trenchless Construction - Tunneling - Augering, Boring & Pipe Ramming

GUIDED BORING

A Guided Boring Machine (GBM) is used to install 305 mm to 3.6 m diameter pipe (12 in to 144 in) with grade and alignment precision. It is commonly used for installations 50 m to 150 m in length (164 ft to 492 ft) or when line and grade accuracy is critical in displaceable soil. Our GBM is extremely versatile and our customers continually approach us with new applications.

The pipe installation involves a two-step process where launch and reception shafts are strategically located to minimize surface disruption. A pilot tube with a theodolite guidance system is then pushed through the ground at the precise grade and alignment specified in the design into the reception shaft. A reaming head is welded to the pilot tube and the casing and the pilot tube is used as a guide to install casing. The GBM can be used in conjunction with auger boring or pipe ramming methodologies.

The Crossing Group - The Tunneling Company - Guided Boring - Trenchless Construction - Tunneling - Augering, Boring & Pipe Ramming

PNEUMATIC PIPE RAMMING

Pipe Ramming is used in a wide variety of soil types including gravel, cobble or sand. A pneumatic hammer is attached to the back of the casing pipe and driven through the material at any angle: from horizontal to vertical. The material is cleaned out of the pipe using an auger boring machine. Pipe Ramming methods are used for pipe diameters of 305 mm to 3.6 m (12 in to 144 in).

The Crossing Group - The Tunneling Company - Pneumatic Pipe Ramming - Tunneling - Augering, Boring & Pipe Ramming