Hydrographic Survey

GEOACE Nigeria Limited offers survey services across a wide range of offshore activities, working on mobile assets ranging from rigs and vessels to ROVs and subsea installations.

Our offshore capabilities span positioning support (rig, vessel, ROV and subsea positioning, tug management, LBL and USBL positioning, deep water operations), geophysical survey and consults (hazard surveys, pre- and post-lay surveys, pipeline surveys, rig move surveys), geotechnical survey and consults (CPT, coring, drill sampling, grab sampling), construction support for offshore builds, well support services (well positioning, jumper metrology, LBL underwater positioning), and pipelay and pipeline support services (laying, inspection, free span correction).

Offshore survey support in Nigeria

We work offshore Nigeria, including in deep water, on fields such as Bonga, Egina and Akpo, for operators and contractors including TOTAL Energies and SNEPCO.

What we do offshore

• Rig and vessel positioning: rig moves, tug management and the positioning of drilling and construction vessels.
• Subsea positioning and metrology: LBL and USBL positioning, ROV and well positioning, tophole positioning, well marking and jumper metrology.
• Bathymetric and geophysical surveys: seabed mapping, hazard surveys including 2DHR seismic, and pre- and post-lay pipeline surveys.
• Geotechnical surveys: CPT, coring, drill sampling and grab sampling.
• Construction and pipelay support: pipeline laying, inspection and free span correction.
• Monitoring: seabed subsidence monitoring over producing fields.

Common questions

What is a hydrographic survey? It measures and maps the seabed and the water above it: depths, the shape of the seabed and what lies on it. It is used for safe navigation, offshore construction, pipelines and drilling.

What is the difference between LBL and USBL positioning? Both fix positions under water using sound. USBL works from a single transceiver on the vessel and suits tracking ROVs and equipment. LBL uses a network of transponders placed on the seabed and gives the higher accuracy needed for metrology and well positioning.

Do you work in deep water? Yes. Recent work includes positioning and metrology on the Bonga, Egina and Akpo fields.