Working in desert areas poses a number of challenges to pipeline construction companies. These include access to the construction site, specialised equipment, constructing through sand dunes, dealing with sandstorms, and ensuring the safety and health of workers in the heat.

Getting traction in sand

In order to transport equipment, pipes and workers to and from the construction site, temporary access and service roads often need to be installed along the pipeline route. Athens-based Consolidated Contractors Company (CCC) Senior Projects Co-ordinator Sami Fidawi says that sourcing harder earth material for roads can often be difficult due to the availability and specifications of the material, and the distance required for its transportation to site.

Often, two tractors are utilised to haul heavy trucks and equipment over sand dunes.

When accessing the site, it is important for workers to be aware of the dangers of driving in the desert. Sandstorms can occur, reducing visibility and increasing the chance of a collision. Sandstorms can also make the pipeline right-of-way (ROW) inaccessible for many vehicles, especially trailers.

McConnell Dowell Australia General Manager – Pipelines Mark Twycross says “There needs to be awareness of two-way traffic with adequate signage and calling on two-way radio protocols to ensure that there are no collisions.”

Mr Fidawi says that another hazard in desert terrain occurs in areas with a high water table. In such areas it is better to elevate the RoW, if suitable earth materials are available, to avoid equipment becoming stuck which necessitates towing, with high risk of equipment damage and lost time.

Indian construction company Punj Lloyd says that it designates transport safety officers in order to mitigate the hazards associated with transporting equipment and pipe to site. The company recently used this technique to successfully transport 19,909sections of pipe 350 km on the Gas Export Capacity Increase Pipeline located in Oman.

Keeping equipment cool under pressure

The equipment sourced for use in desert environments should be tailored to withstand very hot climates. Mr Fidawi says that some equipment features suited for desert terrain include:

• Over-sized cooling systems;
• Air-conditioned cabins; and;
• Non-conventional military-type electronic components.

The use of all-terrain vehicles such as heavy-duty trailers and all-wheel drive personnel carriers is also valuable when operating in extreme heat. Mr Fidawi says that it is important to ensure emergency tools such as spare tyres, backup tanks, basic hand tools, and towing tools are available with all vehicles, in addition to other safety requirements.

Mr Twycross adds that ongoing maintenance and ‘cooling-off’ periods for machinery, as well as lubricants for high temperature working conditions, help to ensure that pipeline equipment does not fail in the heat.

Overcoming construction risks

Mr Fidawi says that large sand dunes often need to be removed to ensure that pipelines are installed in stable terrain. Wider trenches are often dug to allow for side collapses during sandstorms, and extra protection measures, such as wind barriers or tents, are taken while welding to maintain quality.

Magnatech International says that the use of mechanised welding in desert terrain can aid the construction process, as it reduces the physical effort required by workers to weld the pipeline.

Applying field joint coatings to pipelines in desert terrain can also pose challenges. ShawCor subsidiary Canusa CPS has undertaken a detailed analysis of the risks involved in high temperature pipe coating and field joint challenges of pipeline construction in remote locations, including deserts.

In a technical paper authored by Wayne Hodgins and Robert Buchanan, the company examined the effect of temperature fluctuations on exposed coated pipe during construction. The paper found that high daytime temperatures can substantially elevate the pipeline temperature. Overnight lows then created significant steel temperature swings that can have adverse effects on brittle coatings as the pipeline expands and contracts. The paper states that the use of sandbags to support pipe during construction, rather than wood blocking, limits damage to the pipeline coating.

In addition, Canusa says that sandstorms can contaminate the joint coating during installation. This requires correct surface preparation and pre-cleaning prior to blasting.

Mr Fidawi notes that levels of humidity need to be considered when conducting surface preparation before joint coating, and high humidity may require work to be rescheduled to periods of low humidity.

In addition, water for hydrotesting can be difficult to source and can require transportation, particularly if fresh water is required.

Finally, many high pressure pipelines that are constructed in the desert require anchoring so that, when operations commence, any changes in temperature and pressure of the pipeline do not cause it to buckle and ‘snake’ out of the ground.

Pipeline workers in the hot seat

Desert conditions will always represent a challenge with high levels of heat and sandstorms confronting workers onsite.

In the summer months, many activities cannot proceed under harsh conditions or during maximum temperature hours, especially at the peak day hours between 11am and 3pm.

During the windy months, Mr Fidawi says that CCC ensures construction teams start working as early as possible while the wind is calm to make the best possible use of those good hours. This often means workers are on the pipeline spread to start working by sunrise.

He says that mid-day breaks and sometimes selected night-shift options may need to be considered especially for concrete works.

Mr Twycross says that it is important to protect workers against fatigue, dehydration, risks of sun stroke and heat stroke, and eye irritations by paying careful attention to hydration, dietary requirements and sun protection. McConnell Dowell ensures workers are provided with meals containing the correct natural salts that need to be replenished after a day out in the heat.

Russian construction company Stroytransgaz says that campsites along the pipeline route are important to minimise the travelling distance for workers, and maximises their productivity during cooler hours. The company recently completed the 217 km Shaybah – Abqaiq Oil Pipeline in Saudi Arabia, using four villages to house workers when constructing along the pipeline route.

Both McConnell Dowell and CCC stress that all personnel receive first aid and safety training, as well as the use of alternative emergency communication options such as satellite phones and radios as most of the pipeline routes in deserts lack proper mobile coverage.