Efficient Simulation for Low Salinity Waterflooding in Porous and Fractured Reservoirs

Abstract

Low-salinity brine injection has emerged as a promising, cost-effective improved oil recovery (IOR)method for waterflooding reservoirs. Laboratory tests and field applications show that low-salinity waterflooding could lead to significant reduction of residual oil saturation. There has been a growing interest with an increasing number of low-salinity waterflooding studies. However, there are few quantitative studies on flow and transport behavior of low-salinity IOR processes. This paper presents a general mathematic model (1) to incorporate known IOR mechanisms and (2) to quantify low-salinity waterflooding processes. In our mathematical conceptual model, salt is treated as an additional "component" to the aqueous phase, based on the following physical considerations: salt is transported only within the aqueous phase by advection and diffusion, and also subject to adsorption onto rock solids; relative permeability, capillary pressure, and residual oil saturation depend on salinity. Interaction of salt between mobile and immobile water zones is handled rigorously using a multi-domain approach. Fractured rock is handled using the multiple-continuum model or a discrete-fracture modeling approach. The conceptual model is implemented into a general-purpose reservoir simulator for modeling low-salinity IOR processes, using unstructured, regular, and irregular grids, applicable to 1-D, 2-D, and 3-D simulation of low-salinity water injection into porous media and fractured reservoirs. As demonstrated, the model provides a general capability for quantitative evaluation of low-salinity waterflooding in site-specific investigations.

Meeting Name

SPE Reservoir Simulation Symposium (2009: Feb. 2-4, The Woodlands, TX)

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

3D simulations; Aqueous phase; Brine injection; Capillary pressures; Conceptual model; Continuum model; Efficient simulation; Field application; Fracture modeling; Fractured reservoir; Fractured rock; Immobile water; Improved oil recovery; Irregular grids; Laboratory test; Low-salinity water; Mathematic model; Multi domains; On flow; Porous Media; Quantitative evaluation; Quantitative study; Relative permeability; Reservoir simulator; Residual oil saturation; Site-specific; Water-flooding reservoir

International Standard Book Number (ISBN)

978-1605607771

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2009 Society of Petroleum Engineers (SPE), All rights reserved.

Publication Date

01 Feb 2009

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