Rock physics modeling to monitor movement of CO2 in Sleipner gas field, North Sea: An ideal CCS field

• DOI: 10.1190/segam2014-0970.1
• Publication Date: 2014-08-05T18:07:51Z
• Authors: Ranjana Ghosh*; Nimisha Vedanti; Reetam Biswas; Mrinal K. Sen
• Keywords: Natural gas field; North sea

Summary Sleipner gas field in the North Sea is world's first industrial scale CO2 injection project designed specifically to reduce emission of greenhouse gas. Here separated from natural produced at injected into Utsira sand, which a major saline aquifer basin. In time-lapse three-dimensional seismic data (4D), plume imaged as number bright sub-horizontal reflections within reservoir. Correlation log with indicates that accumulates series interbedded sandstones and mudstones beneath thick cap rock mudstone. Nine reflective horizons have been mapped reservoir on six surveys 1999 2008. Comparison baseline survey 1994 (pre-injection) provides clear impression migration plume. this paper, we attempt model distribution quantitatively by applying pressure-dependent differential effective medium (PDEM) theory using 4D data. Pre- post-injection acoustic impedances are calculated inverting respectively post-stack 2001 model-based inversion technique. 3D saturation volume estimated PDEM inverted impedance year taking reference results pre-injection 1994. Since type seldom known, estimate both homogeneous patchy pattern our physics model. We for be 0–20% patches 0–80% total porosity ~200 m unit. 5–7% uncertainty predicted Monte-Carlo simulation Our indicate large amount accumulated sand layers capped mud layers, though some may dissolved uniformly water.