Niger Delta Pressure Study Phase 1: Deep and ultra deep water offshore

Introduction

This is the first authoritative study of subsurface pressures in the Niger Delta deep water and ultra deep water areas, based on 94% of exploration and appraisal wells drilled.

The Niger Delta pressure study delivers an understanding of the effect of overpressure on hydrocarbon trapping in the Niger Delta, and discusses the implications for exploration in the region.  The high capture of well data contributes to the building of predictive relationships critical to the planning of safe deep water wells.

This study investigates:

  • Distribution and control of overpressures including variations in top of overpressure and vertical/lateral seals.
  • Evidence for lateral transfer (leading to higher than expected pressures when drilling).
  • Trap integrity assessment – seal breach risking and top seal failure.
  • Lateral drainage and implications for migration, hydrodynamic flow and tilted OWCs. 

Benefits

  • See how overpressure relates to trapping both in high overpressure areas, where there is potential for seal breach and dry wells, and also in low overpressure areas in laterally draining reservoirs. 
  • Planning of safe wells by the prediction of pre-drill shale and reservoir pressures, fracture strength and overburden. 
  • Enhanced understanding of the role of pressure and its control on hydrocarbon potential in the area.

Deliverables

  • A bound report and set of maps (hard & electronic) 
  • Overpressure maps for key stratigraphic units, including: Pliocene/Pleistocene, Miocene (Upper/Middle/Lower), Oligocene, Eocene and Cretaceous 
  • Single-and multi-well pressure-depth plots of pore pressures 
  • A detailed discussion of the relationship between reservoir pressures & pressures in adjacent shales 
  • A predictive algorithm for fracture and overburden pressure 
  • Analysis of seal breach relations and implications for dry holes 
  • Case studies on evidence for lateral drainage and hydrodynamic trapping linked to regional fluid flow 
  • Comparison with relevant worldwide analogues 
  • ArcGIS shape files for all map elements 
  • Comprehensive data summary of all derivative results e.g. overpressure values


Study coverage

  • Niger Delta Phase 1 – DeepWater and Ultra-DeepWater 
  • Niger Delta Phase 2 – Shallow Water and Continental Shelf Niger 
  • Delta Phase 3 – Onshore and Swamp