Major Integrity Programs

Our Client
Mobil Producing Nigeria ('MPN') is a joint venture between ExxonMobil and the Nigerian National Petroleum Corporation and is involved in oil and gas exploration and production activities in Nigeria. MPN is the second-largest oil producer in Nigeria and operates a large terminal near Eket in southeastern Nigeria, the Qua Ibo Terminal.

Our Work
The Major Integrity Programs consist of the construction of new offshore platforms, revamping existing platforms, replacing numerous subsea pipelines, and substantial onshore works, including pipeline shore crossings.

Van Oord was involved in the installation of three subsea pipelines, replacing the ones that had reached their technical life span. The scope of work included the dredging of a trench approximately 3 km long and 80 m wide. In total, about 750,000 m3 was dredged. Climatic conditions were a factor in the work and forced the project to be done between mid-October and mid-February. During the rest of the year, swell-generated waves from the Atlantic Ocean make dredging impossible.

The cutter suction dredger Hector started dredging from the sea end of the trench while a cofferdam was constructed from the shoreline into the sea. The 137-metre-long cofferdam was constructed to keep the onshore trench free from infill by wave action in the inter-tidal zone. The Hector dredged until it reached the cofferdam, while the inside of the cofferdam was excavated with land-based excavation machinery. Upon completion of the formation of the trench, the three pipelines were pulled ashore. Once the pipes were pulled, the cofferdam was removed and the beach restored to its original state.

Our Results
The work Van Oord has done will ensure that oil transport can continue safely through the new pipes from the MPN offshore platforms to the Qua Ibo Terminal for processing and back for exportation.