Challenges and achievements
The main challenges encompassed by GSP during the installation of the Chihuahua Corridor gas pipeline were:
- Tight project schedule (15 months), stringent welding standards (the overall weld reject rate for the project resulted to be at the end just 1%).
- Transportation of the 24 m pipes from the factories in the US and Mexico to the discharge station, and then to the temporary storage pipe yards before their stringing along the pipeline right of way.
The construction activities were driven by the dedicated project management team, which managed to achieve excellent performances both in terms of production and quality. Two mainline welding crews were utilised, each one achieving over the project life an average between 63 and 83 joints/d with peaks up to 120 joints/d, reaching a breakthrough of 2 km/d per work front.
In order to guarantee this performance and to keep all phases close to each other, a great civil and mechanical effort was made allocating the necessary resources (trenchers, padding machines, excavations, trucks, among others) to reach a performance between 1100 and 2000 m/d per work front. The mainline construction works commenced in August 2012 and ended in January 2013.
Most of the trenching was executed by trenchers except for areas of hard rock were blasting was implements. All trenches were padded with selected material produced by the mobile screening plants “Vulcano”. Pipe hauling activities were specifically analysed and planned considering the characteristics of the pipes to be installed: quantity, weight, diameter, thickness and length.
Every possible route from the pick-up points to the delivery points was specifically analysed and the best route was finally selected on the basis of considerations such as security and road conditions. In general, the pipe length was 24 m. Pipes were delivered by railroad to the main temporary pipe yards of “Terrazas” and “Carrizales”, where a spur rail way was built to facilitate offloading of wagon cars. Excavators with vacuum lift were utilised for the offloading. All pipes for the pipe stack areas were moved by trucks with an expandable platform to carry the 24 m long pipes. All trucks used for the activity were monitored by the GPS active tracking system. The information about trucks and pipes movements were available 24 hours a day in real-time and constantly analysed in the logistic base of San Luis Potosí in order to ensure observance of speed limits, detect any deviations from the assigned route and any uncommon behaviour or necessary assistance.
Sidebooms holding pipe during lower-in activity.
Specialised machinery for special works
The FastWeld System commonly utilised by GSP for mainline welding has the following characteristics: internal line-up clamp for better alignment of pipe; two simultaneous welding heads; and welding is performed under argon or CO2 gas protection, or with mixture of the two gases. The system incorporates a programmable logic controller (PLC) and a memory card to manage the welding parameters that can be customised along the circumference of the pipe and is equipped with self-diagnostics to resolve potential problems.
The product of a job well done
During the construction phase of the pipeline along its 383 km, no incidents or complains from communities were presented. For the first time in Mexican private pipelines, the project was completed ahead of the commercial operation date.
The Chihuahua Corridor gas pipeline was inaugurated on 14th August, 2013 by the President of Mexico Enrique Peña Nieto in the presence of the governor of the State of Chihuahua, commending a project completed in time, without incidents, which is currently operated by Tarahumara Pipeline, S. de RL de C.V.
Written by Giacomo Bonfanti, Luca Romanengo and Alejandro Ceballos, GDI-SICIM PIPELINES S.A. DE C.V., and edited by Rosalie Starling
Read the article online at: https://www.hydrocarbonengineering.com/special-reports/09072014/renewing_mexicos_energy_future_part_two_576/