AKK River Niger Crossing: How HDD Helped Complete a Critical Pipeline Connection

Nigeria has one of Africa’s largest natural gas reserves. But having gas underground is only one part of the opportunity. The country also needs the infrastructure to move that gas to power plants, industries and communities where it can support economic activity.

The Ajaokuta–Kaduna–Kano Gas Pipeline, commonly known as the AKK pipeline, is part of that wider infrastructure. The pipeline forms part of the Trans Nigeria Gas Pipeline network and is intended to improve the movement of natural gas towards central and northern Nigeria.

Along such a long route, however, not every section can be built in the same way. One of the most challenging sections was the crossing beneath the River Niger.

For the AKK pipeline route to continue across the River Niger, a 40-inch gas pipeline had to be installed beneath the waterway. Crossing a major river presents a very different challenge from laying pipelines across open land.

Traditional open-cut construction would require excavation through the riverbed. For a crossing of this scale, that can create significant engineering, environmental and construction challenges. Instead, the project used Horizontal Directional Drilling, or HDD.

HDD allows a pipeline to travel beneath an obstacle through a carefully engineered underground bore, reducing the need to disturb the surface directly above the crossing. But choosing HDD did not make the crossing simple.

Previous specialist HDD attempts had not completed this section of the project, leaving the crossing unfinished and continuing to affect the connection and commissioning of the wider pipeline.

PCE Nigeria was subsequently appointed to execute the crossing package.

The River Niger crossing extended for 1,565 metres underground and reached a depth of approximately 16 metres. The challenge was not just the distance.

The drilling path passed through changing ground conditions that included sand, gravel and rock. Each behaves differently during drilling, so the crossing required an approach that could respond to those changing conditions while maintaining a stable underground route for the pipeline. PCE Nigeria Limited

The size of the pipeline added another level of complexity.

At 40 inches in diameter, the pipeline required a sufficiently large and stable bore to allow it to be pulled through safely after drilling and enlargement of the underground path. Long-distance HDD projects therefore depend on more than drilling equipment alone. The method, drilling fluid, equipment capacity and coordination of the teams all have to work together.

We developed our HDD approach around the conditions encountered beneath the River Niger. For the pilot hole, the team used dual-rig intersecting technology. This involved drilling from opposite sides of the crossing and bringing the underground paths together.

We also used dual-rig synchronous operations during the reaming stages, when the bore was enlarged to create sufficient space for the pipeline. A specially developed drilling-fluid formula was used to support drilling through the combination of sand, gravel and rock, while high-capacity HDD equipment supported the demands of the long crossing.

The technical details matter, but the wider principle is straightforward: the drilling method had to be designed around the actual conditions beneath the river rather than treating the crossing as a standard HDD job.

That approach is consistent with PCE Nigeria’s wider project method, which begins with understanding the route and ground conditions before engineering and preparing the equipment, people and materials required for execution.

Work on the crossing began on 25 March 2025. On 26 July 2025, we completed the installation of the 40-inch AKK gas pipeline beneath the River Niger. Completing the 1.565-kilometre crossing resolved a project-critical section that had previously remained unfinished. Its importance therefore went beyond successfully drilling beneath a river.

The crossing helped remove an obstacle affecting the connection and commissioning of the wider AKK pipeline system.

Large infrastructure projects are often discussed in terms of their total length, investment value or national importance. But their success can depend on individual sections. A pipeline may extend for hundreds of kilometres, yet one unresolved river, road or difficult-ground crossing can affect progress across the wider route.

The AKK River Niger crossing illustrates that point.

Completing it helped move the wider project closer to achieving its intended purpose: improving the movement of natural gas into parts of Nigeria where additional gas infrastructure can support power generation, manufacturing and other productive economic activity. That has broader importance for Nigeria.

Reliable gas infrastructure can support industries that require a consistent energy supply, encourage investment in areas connected to the network and strengthen the infrastructure needed for long-term economic development.

The value of the crossing is therefore not simply the 1,565 metres beneath the River Niger. It is the connection that those 1,565 metres helped make possible.

The AKK crossing also provides a practical example of what Horizontal Directional Drilling can achieve on complex Nigerian infrastructure projects. Nigeria’s terrain includes major rivers, densely developed areas, roads, wetlands and changing geological conditions. Future pipeline routes will continue to encounter many of these obstacles.

HDD gives project developers another option when open-cut construction would be impractical or excessively disruptive. The AKK project also demonstrates the importance of combining international HDD methods with the ability to execute effectively under Nigerian project conditions. That includes understanding local geology and logistics, mobilising suitable equipment and coordinating people, materials and technical expertise around the demands of the crossing.

For PCE Nigeria, the AKK River Niger crossing became more than a completed project. It provided demonstrated experience in delivering a long-distance, large-diameter HDD crossing through mixed geological conditions in Nigeria.

That experience can inform future river crossings, road crossings and other complex pipeline sections where conventional excavation may not be the best solution.

PCE Nigeria currently provides specialist HDD engineering and construction for river, road, coastal and complex-ground crossings, with capability for pipeline diameters of up to 48 inches. As Nigeria continues to expand gas and other pipeline infrastructure, the ability to complete difficult sections such as the River Niger crossing will remain an important part of delivering the wider network.

The AKK crossing shows what that looks like in practice: one difficult connection completed so a much larger infrastructure project can move forward.

Learn more about the AKK River Niger Crossing or explore PCE Nigeria’s HDD capabilities.

For project enquiries, contact wanyang@pcenigeria.com.