By Hussein Boffu
Substantial discoveries of oil and natural gas have been made in East Africa. But oil and gas are worth less at the wellheads. It needs to be moved, processed ,refined, and delivered to the distribution point or to consumers.
That’s where the huge project such East African crude oi pipeline come in. Today, I thought I would take a moment to share some key insight on the pipeline construction.
Identifying the works performed during pipeline construction will give you insight on the role your business can play in any oil and gas pipeline project in Tanzania , East Africa and beyond.
Building pipelines involves enormous activities ranging from the surveying, grading, clearing, digging ditches, pipeline welding, to X-ray welds to ensure its quality.
Here are the activities occurring in the crude oil pipeline project:
1. Construction Survey
The first step in the construction of the oil project is civil survey. The survey team will locate and mark facilities such as utility lines, the right of ways, working spaces, and sensitive resources to allow construction activities. Also, the survey team might mark the areas for digging trench. This helps construction crews to minimize the impact on the surrounding areas as they have a clear picture of the construction activities.
This phase involves removing all the obstacles that can hinder the construction process along the pipeline route. It consists of cuttings, burning, and removal of trees, crops, vegetation, and bushes along the construction corridor. Once the area is well cleared, it easy to transport construction equipment to the site. Heavy machines such as
bulldozer, caterpillar, and chainsaw may be used during this activity.
The next activity in the construction of the oil and gas pipeline project is grading. This is the leveling of the ground so as to keep safe work and level surface operation for the pipeline construction crew and help heavy machine and huge construction equipment to operate smoothly along the pipeline route. Also, since the oil and gas pipeline might pass through various topographies, leveling minimizes excessive pipes bending, for example, in the areas of steep slopes.
4. Top Soil Stripping
This activity will include the removal of the top soil from the construction corridor. And this will be done to preserve the original topsoil to its natural state. The top soil will be protected and replaced once construction is completed.
The next stage of the the oil and gas pipeline construction process is digging the trench. During this trenching operation, the crews will use excavators to remove material from the trench.
Once the trench operation is finished, the pipe segment will be placed to the dug trench. Trailers can be used to
moves pipes from the storage yard to the trench or construction corridor. That is called stringing.
The oil and gas pipeline may not not be on the same level along the route. To fit with topography changes along the pipeline route, the pipes need to be bent using specialized bending machines so as to fit with the land topography.
8. Line Up
In this stage of the oil pipeline construction procedures, pipes will be lined up one after the other in the construction corridor.
The different sections of the steel pipes will be joined together to form a continuous length. Each joint will be expertly welded to prevent leakage. Anybody can learn to fire up the two pieces of iron. But you can’t do amateur welding in pipeline welding. Pipeline welders know the temperature and the porosity of the welds. Welders have education institutions that train and certify them to become pipeline welders. Welders need to be highly trained. When you weld a ten-kilometer pipe, you form a ten kilometer long pipe. 1
10. X-ray and Welded Repair
Pipeline welding is not all about welding pipes together but also x-ray to ensure its quality. Once the segments of the
pipes are welded, the welds will be checked with x-rays and ultrasonic equipment. This is done to increase the integrity of the pipes. So it ensures the welds are safe, secured, and would not break. Qualified welders take x-rays of the pipe welds, and once they identify any flaw, the welds are repaired (they are cut out) and the workers will make new welds.
11. Weld Coating
Once the welding is completed and tested, the next step is coating it. In this stage, the surface of the pipes will be coated so as to minimize and control corrosion risks of the pipes. Welds will be coated prior to be placed to the right of way where all the construction activities occur. Before coating, the crew will make sure the pipes are clean by removing debris and all kinds of dirty that might interact with the coatings.
12. Coating Inspection
To ensure the surface of the pipes are free from defects, such as scratches, workers will use high voltage specialized equipment to detect any defect before the pipeline is placed into ground.
This is the process of laying pipe into the ground. In this step, the welded pipe will be placed down into the trench. The specialized construction equipment, such as the sideboom machine, will lift the pipe and lower it into the
trench. During this phase, precautions are taken to ensure there are no damages to coating when they lower the pipelines into the trench.
14. As Built Survey.
This survey is performed over the course of the pipeline construction to record all the changes happening as pipeline construction is in progress. This provides important information to know the level of completion the project has reached. This helps to make changes to ensure the construction schedule is met.
15. Pad and Backfill
This activity involves placing back the excavated subsoil into the trench. You simply fill back the material back into the trench or hole you had previously dug. It involves refilling the trench to cover the pipeline with both top and subsoil. Top soil removed during top soil stripping phase and sub soil removed during trench digging will be placed back to cover the pipeline.
16. As Built Survey
Again, the survey team carries out as built survey is carried out after completion of the pipeline construction to identify whether the job is done well. The survey team will record information on what was actually constructed.
17. Clean Up and Remediation
The final stage of the crude oil construction is clean up and remediation. This activity is done to turn the construction
site as closely to its original pre construction condition as possible. Examples of activity taking place in this stage is removal of construction materials, removal of large rocks, performance of final grading, etc.