Multiphysics and Multiscale Methods for Modeling Fluid Flow Through Naturally Fractured Carbonate Karst Reservoirs

Abstract

Modeling and numerical simulations of Carbonate karst reservoirs is a challenging problem because of the presence of vugs and caves which are connected through fracture networks at multiple scales. In this paper, we propose a unified approach to this problem by using the Stokes-Brinkman equations which combine both Stokes and Darcy flows. These equations are capable of representing porous media (porous rock) as well as free-flow regions (fractures, vugs, and caves) in a single system of equations. The Stokes-Brinkman equations also generalize the traditional Darcy-Stokes coupling without sacrificing the modeling rigor. Thus, it allows us to use a single set of equations to represent multiphysics phenomena on multiple scales. The local Stokes-Brinkman equations are used to perform accurate scale-up. We present numerical results for permeable rock matrix populated with elliptical vugs and we consider upscaling to two different coarse-scale grids-5Â5 and 10Â10. Both constant and variable background permeability matrices are considered and the effect the vugs have on the overall permeability is evaluated. The Stokes-Brinkman equations are also used to study several vug/cave configurations which are typical of Tahe oilfield in China.

Dynamic analysis of oil‐water two‐phase flow for a multiple‐fractured horizontal well with multiple finite‐conductivity fractures in triple media carbonate reservoir

“…[11]; Popov et al. [21]). Each reservoir is composed of different combinations of matrix, fracture, and vug systems, and thus it has various properties of porosity, permeability, and fluid transport behavior.…”

Displacement efficiency in the water flooding process in fracture–vuggy reservoirs

“…The Tahe (TH) fracture-vuggy reservoirs in Xinjiang, China, are buried at considerable depths, exhibit strong heterogeneity, and are difficult to develop (Popov et al 2009;Gu and Chalaturnyk 2010;Noushabadi et al 2011). Fractures provide the oil-storing spaces and flow channels of a reservoir.…”

Dual permeability flow behavior for modeling horizontal well production in fractured-vuggy carbonate reservoirs

“…Carbonate reservoirs have complex structures, and they have generated great scientific interests while posing significant research challenges (Gua and Chalaturnyk, 2010;Jazayeri Noushabadi et al, 2011;Popov et al, 2009;Rawnsley et al, 2007;Rzonca, 2008). Each reservoir is composed of different combinations of matrix, fracture, and vug systems, and, thus, has varying properties of porosity, permeability, and fluid transport behavior (Abdassah and Ershaghi, 1986;Liu et al, 2003;Mai and Kantzas, 2007).…”