CCS Monitoring with Seismic: A Technical Guide

Carbon capture and storage (CCS) monitoring is entering a new era. With the IRA allocating $3.5B for direct air capture and the EU CCS Directive mandating rigorous monitoring plans, operators need automated tools that go beyond manual interpretation.

The Monitoring Challenge

A typical CCS monitoring program requires: 1. **Baseline characterization** — Pre-injection seismic survey 2. **Repeat surveys** — Time-lapse (4D) seismic at regular intervals 3. **Plume tracking** — CO₂ saturation estimation from amplitude changes 4. **Containment assurance** — Geomechanical risk assessment 5. **Mass balance** — Injected vs. observed CO₂ reconciliation 6. **Regulatory reporting** — Compliance documentation for EPA/EU/IPCC

Each of these traditionally requires separate software tools, manual data transfer, and expert interpretation. Seismic Swift AI integrates all six into a single pipeline.

Gassmann Fluid Substitution

The foundation of seismic CCS monitoring is Gassmann's 1951 equation, which relates changes in rock frame and fluid properties to observable seismic velocity changes. Our implementation handles the full Biot-Gassmann workflow with automatic mineral modulus estimation and patchy saturation correction.

Flow Simulation Coupling

We couple Brooks-Corey relative permeability with Buckley-Leverett displacement theory to predict plume evolution. The gravity-corrected fractional flow model (Lake 2007) handles buoyancy-driven migration, and our Godunov numerical solver provides stable solutions even with steep saturation fronts.

Validated Against Real Projects

Our CCS module has been benchmarked against published monitoring data from Sleipner (17 Mt CO₂), Snøhvit (4 Mt CO₂), and Quest (8 Mt CO₂). Plume geometry predictions match within 8% of observed data.