Seismic Pore Pressure Prediction (PPP) provides volumetric estimates of pore pressure across reservoirs, fields and even at the basin scale. These can be used by geologists and reservoir engineers to improve understanding of hydrocarbon basins, identify potential drilling hazards and improve well positioning.

CGGVeritas combines expertise in high-resolution seismic velocities, petrophysical modelling and well data integration to deliver a range of seismic pore pressure services.

Seismic Interval Velocity	Predicted Overpressure
Pore Pressure Prediction (PPP) for a proposed well in the Central North Sea High-Pressure High-Temperature area.
The base chalk (marked with a white arrow) acts as a seal creating substantial overpressure in the reservoirs below. Accurate, high-resolution velocities from dense, automated picking are used as the basis for the prediction.	A lithology-dependent normal compaction trend has been used to improve the accuracy of the predicted pressures within and below the chalk. The resulting well prognosis indicates that the well trajectory avoids hazardous, highly over-pressured zones.

FEATURES

• High-resolution seismic velocities
• Integrated workflow from seismic to petrophysics
• Rigorous calibration of velocities and rock physics model with well data
• Spatially varying and lithology-dependent rock physics model.

• Well calibrated field-scale pore pressure volumes for:

- Development well planning
- Calculation of safe mud-weight window
- Drilling hazard prediction

• Basin-scale pore pressure volumes for:

- Improved exploration well positioning
- Source maturation modelling
- Seal recognition and hydrocarbon migration modelling

Basin-Scale Prediction Enhances Exploration

Pore pressure prediction can also be performed across large areas and used as a more qualitative exploration tool at a basin scale. These large volumes provide an overview of pressure and fluid behaviour within the basin and can be used to identify important features, such as the behaviour of faults (see example). In this context pore-pressure prediction becomes a tool for geologists and can help in understanding regional basin dynamics and the identification and de-risking of new prospects.

Highlight from a basin-scale pore pressure study offshore Nigeria, showing a pressure contrast across a sealing fault (1). The reservoir (2) sits above over-pressured shales (3) in a transitional interval containing some higher pressure layers.