Offshore decisions are only as good as the survey data behind them. NEXA Energy & Support Services delivers rig positioning, bathymetry and the full suite of marine survey operations as one integrated programme, supporting operators across exploration, installation and inspection phases in shallow water, swamp and deepwater Nigeria.
Why Bathymetry Alone Is Not Enough
Multibeam and single-beam echo sounding map the seabed surface. That is essential, but it answers only one question: how deep is it? A jack-up leg, an anchor, a pipeline or a platform jacket interacts with what lies beneath the surface and with the water column above it. Field development therefore needs bathymetry integrated with geophysical, geotechnical, oceanographic and positioning data. NEXA scopes every survey around the engineering decision it has to support, not around a single instrument.
Rig and Vessel Positioning
- Pre-move site surveys to confirm seabed conditions, hazards and clearance from existing infrastructure
- DGNSS/DGPS positioning with survey-grade corrections for jack-up, semi-submersible and drillship moves
- Anchor pattern design and verification, including anchor-handling support
- Jack-up leg penetration and punch-through assessment from integrated geotechnical data
- Real-time position monitoring during spud-in and final set-down
Bathymetric and Hydrographic Survey
- Multibeam echo sounder (MBES) for full-coverage seabed mapping
- Single-beam echo sounder (SBES) for shallow-water, swamp and river channels
- Tide and sound-velocity correction to chart datum
- Deliverables: digital terrain models, contour charts and seabed classification to IHO standards
Geophysical Survey
- Side-scan sonar for seabed features, debris and pipeline exposure
- Sub-bottom profiler for shallow stratigraphy and buried hazards
- Magnetometer for buried pipelines, cables, wrecks and ordnance
- 2D high-resolution seismic for shallow gas and geohazard assessment
- Pipeline and cable route surveys, pre-lay and as-laid
Geotechnical Investigation
- Seabed cone penetration testing (CPT) and vibrocore sampling
- Boreholes for platform and jack-up foundation design
- Laboratory classification and strength testing
- Integrated ground models combining geophysical and geotechnical data
Oceanographic and Metocean Services
- Current profiling (ADCP), wave and tide measurement
- Metocean data for installation weather windows and design criteria
- Water-quality and environmental baseline sampling
Across the Field Life Cycle
| Phase | What NEXA delivers |
|---|---|
| Exploration | Site surveys, geohazard assessment, shallow-gas screening, rig positioning for exploration wells |
| Installation | Rig moves, anchor handling support, pipeline and cable route surveys, touchdown monitoring, as-laid and as-built surveys |
| Inspection | Pipeline free-span and exposure surveys, platform and seabed integrity surveys, scour monitoring, decommissioning surveys |
Integrated with Drilling Support
Positioning and site survey are the first step in NEXA's offshore drilling support. They connect directly to drilling rig provision, drilling and completion fluids, and facility upgrade and maintenance work, so one contractor carries accountability from survey line to spud.
Compliance and Local Content
NEXA is 100% Nigerian-owned. Survey operations are carried out in line with NUPRC and NIMASA requirements, NCDMB Nigerian Content obligations under the NOGICD Act 2010, and ISO 9001, 14001 and 45001 standards. Survey crews are competency-assessed and offshore-certified.