HDD – a Grande idea
South American gas company GasTransBoliviano is currently undertaking a 2.7 km HDD drive under the Rio Grande river as part of a project to secure gas deliveries through the Bolivia – Brazil Pipeline.
The crossing is being constructed as an alternative in case of failure on the existing 1,500 m Rio Grande crossing.
Intense rain during the previous three wet seasons has eroded the west bank of the river to expose the entry point of the current crossing.
GasTransBoliviano responded to this situation in 2007 and 2008 by installing various defensive systems and supports for the pipeline.
While these works were able to minimise the risk of material impact to the pipeline, an engineering study concluded that the best long-term solution was to construct a new crossing, running longer than the existing one under the Rio Grande.
This new crossing is in a duct width of 32 inches installed below the riverbed via HDD. The length of this new crossing will be approximately 2.7 km, becoming one of the longest installations worldwide.
GTB is currently widening the pilot hole to 46 inches in diameter and expects drilling work to be completed in early May 2011. Once drilling is completed, GTB will pull the 32 inch diameter pipeline through the hole.
The new crossing is expected to be operational by July 2011 and will prevent any interruptions in natural gas exports to Brazil.
Mark it in your calendars!
The 2012 ISTT No-Dig conference will be held in SÃ£o Paulo, Brazil from 12-14 November.