Direct Pipe Method Proves Comes To U.S.

November 2011, Vol. 66 No. 11

REM Directional successfully installed three underground pipelines using the Direct Pipe method for the first time in the United States. The systems was used on a Florida horizontal directional drilling project that installed a natural gas pipeline under a highway.

The project started with crews setting up a launch pad on a sod farm in Arcadia, FL, in preparation to install a 705‐foot, 30-inch diameter natural gas pipeline under Highway 70. This successful pioneer run was completed in just three days. During the installation, REM also implemented the use of a Pipe Thruster, which can apply an additional 500 metric tons of pushing and pulling power when used to aid HDD rigs.

Herrenknecht AG in Germany designed both the Direct Pipe method and Pipe Thruster equipment. Said Theo Hundertpfund, manager of after sales service for Herrenknecht AG, Utility Tunneling Division, “First and foremost we would like to thank REM Directional, Inc., who placed their trust in us. We know that it is only possible to set new milestones in technological developments when all parties involved work together to continue the story of innovation in mechanized tunneling with smart concepts and strong determination.”

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Originally making its debut in September 2007, the Direct Pipe method was successfully tested at a crossing of the Rhine River near Worms, Germany. This method is comprised of two traditional drilling methods: microtunneling and HDD.

Known for being a rapid, single‐step process, Direct Pipe is more accurate than using traditional methods alone and is considered optimal for precise installations required for projects leading to oil and gas refineries and power plants.

Accuracy
The accuracy of this method is based on instrumentation and includes the use of a gyrocompass and hydrostatic water level to help guide the AVN machine and product pipe to their destination by monitoring vertical depths and horizontal deviations. This curve monitoring is conducted from an above ground drill cab, which allowed REM to monitor the bore closely and make necessary corrections to both vertical and horizontal paths to keep the machine and product pipe on target.

The microtunneling head of the machine also monitors the annular pressure at all times, which eliminates mud frac outs from rising to the surface. This operation too is conducted from the drill cab.