2007, Effect of heterogeneity in capillary pressure on buoyancy driven flow of CO2

Content Provider	CiteSeerX
Author	Saadatpoor, Ehsan Bryant, Steven L. Sepehrnoori, Kamy
Description	DOE/NETL Sixth Annual Conference on Carbon Capture and Sequestration
Abstract	Residual phase trapping of CO2 injected into aquifers is a key mechanism for reducing risk of leakage. The “inject low and let rise ” strategy of storing CO2 in deep saline aquifers is one method to maximize residual trapping. In this strategy, the more uniform the front of the rising CO2, the greater the amount of CO2 trapped in this form. Previous studies have indicated that capillary pressure promotes the uniformity of the front by dampening its inherent instability. Typically these studies were done with a few (often one, never more than ten) rock types, with each type having a different capillary pressure curve. In this work we show that if capillary entry pressure varies spatially at the same length scale as the permeability – a geologically and petrophysically realistic situation – the dynamics of the rising front can be qualitatively different. As a result, the plume velocity and residual phase trapping can be dramatically different. We study this effect through a series of numerical simulations with GEM-GHG, a commercial reservoir simulator adapted to CO2 storage applications. After generating geostatistical realizations of permeability, we scale a reference capillary pressure curve using the Leverett j-function so that each grid block has Pc-Sw curve physically consistent with its permeability. For the purposes of illustrating the effect on buoyancy driven flow, we idealize the post-injection distribution of CO2 as a large initial
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Subject Keyword	Grid Block Post-injection Distribution Different Capillary Pressure Curve Geostatistical Realization Residual Trapping Numerical Simulation Co2 Storage Application Residual Phase Trapping Length Scale Rock Type Previous Study Reference Capillary Pressure Curve Commercial Reservoir Simulator Key Mechanism Realistic Situation Plume Velocity Capillary Pressure Inherent Instability Leverett J-function Pc-sw Curve Capillary Entry Pressure Deep Saline Aquifer
Content Type	Text
Resource Type	Conference Proceedings