As the oil and gas industry moves into deep-water environments to extract more hydrocarbons to meet rising global demands, offshore pipelines play a critical role in helping petroleum companies deliver products from ocean mines to businesses, factories, and homes.
While pipeline installation methods have significantly evolved over the last few decades. Laying pipes along the seafloor is still riddled with diverse, complex challenges. The teams need to ensure the pipes reach the ocean bed without damage.
In addition, buoyancy impacts the pipe-laying process in both negative and positive ways. The pipes generally weigh less in water when filled with air. This reduces the stress on the pipe-lay vessels. However, the pipes require a downward force to remain in place once set on the ocean bed.
It can be provided easily with the weight of oil when it passes through the pipes. However, gas doesn’t weigh enough to keep the pipelines from drifting across the seafloor. The thickness and insulation are usually planned to ward off the hydrostatic pressure and keep the pipes in place in deep-water scenarios. But concrete is poured over the lines for shallow-water situations to keep them in place.
Pipeline manufacturers and installers utilize three primary ways to lay sub-sea pipelines. Experienced experts at CNPS will walk you down each of the methods briefly to help you understand how offshore pipeline installation works.
This type of offshore pipe installation involves lines being suspended in the water through buoyancy modules. Then tugboats tow the assembled pipelines into place. The buoyancy modules are flooded with water or removed when the pipeline is afloat in the right spot.
There are four primary ways tow-in installation tows the pipe above the ocean floor, partway underwater, at the surface level, or directly along the seabed. The pipeline is towed on the water’s surface with a tug in surface tow. The buoyancy module keeps the towed pipe on top of the water when it’s in the right place.
The mid-depth tow uses fewer buoyancy modules and keeps the pipeline at a submerged level using the forward speed of tug boats. The pipeline settles to the seabed once the forward motion halts.
Chains and buoyancy modules are used in off-bottom tows for added weight. They work against one another to keep the pipeline above the ocean floor. Once on location, the pipes settle to the seabed when the buoyancy modules are removed.
Bottom tow is another method where the pipes are dragged along the ocean bed without buoyancy modules. This works in shallow-water pipeline installations as long as the sea floor is flat and soft.
Alt-text: offshore oil rig
The name reflects the S-shape pipes make when they curve between the ocean floor and the boat installing it. Workers onboard pipe-lay vessels weld different pipe sections in this installation.
As the vessel moves forward, the workers gradually lower the assembled pipeline of the boat’s stern to the seabed through a type of support structure called the stinger. The S-lay offshore pipe installation requires workers to maintain adequate tension so the pipe doesn’t buckle or get damaged when moving from the vessel to the sea floor.
This type of offshore pipeline installation is very similar to the S-lay installation method. Both installation techniques require the assembly of pipes on vessels, which are lowered to the ocean floor from the stern of the boat.
The primary difference, however, is that the tall tower on the boat lifts the assembled pipeline upward. This gives it a straight angle when it enters the ocean.
It creates a curved J-shape between the vessel and the ocean and reduces stress on the line as it bends toward the intended destination. This reduced tension makes this offshore pipeline installation preferable for more intense ocean currents and deeper waters.
High-Quality Fiberglass Piping Systems for Efficient Offshore Pipeline Installation
The key to efficient offshore pipeline installation, however, lies in the skills and geology tools, and equipment used by the onsite teams. Technological advancements have helped us develop extremely precise tools and high-quality GRP, RTP, GRE, and FRP piping systems to make things even more efficient.
CNPS also offers a wide range of other solutions that have helped O&G companies optimize yields and improve safety and results in exploration and extraction operations.
Besides glass-reinforced plastic pipes, we also provide mud logging equipment alloy OCTG, GRE casing solutions, and other cutting-edge and geological field supplies to the oil and gas, water, industrial, and marine & offshore sectors worldwide.
You can set up a consultation with experts at CNPS to discuss our range of ISO and API-compliant geological supplies and fiberglass pipes for sale. We’ve made all the information available online, but our representatives are also easily reachable via a quick call.