Keni Zhang

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Simulations are routinely used to study the process of carbon dioxide (CO 2) sequestration in saline aquifers. In this paper, we describe the modeling and simulation of the dissolution-diffusion-convection process based on a total velocity splitting formulation for a variable-density incompressible single-phase model. A second-order accurate sequential(More)
TOUGH2-MP is a massively parallel (MP) version of the TOUGH2 code, designed for computationally efficient parallel simulation of isothermal and nonisothermal flows of multicomponent, multiphase fluids in one, two, and three-dimensional porous and fractured media. In recent years, computational requirements have become increasingly intensive in large or(More)
mountain-scale UZ flow model (Wu et al., 2003), which is in turn based on the analysis and results of the above-We present a large-scale modeling study characterizing fluid flow referenced work (as well as many other studies). Build-and tracer transport in the unsaturated zone (UZ) of Yucca Mountain, Nevada, the proposed underground repository site for(More)
This paper presents an efficient massively parallel scheme for modeling large-scale multiphase flow, multicomponent transport and heat transfer in porous and fractured reservoirs. The new scheme is implemented into a parallel version of the TOUGH2 code and the numerical performance is tested on a Cray T3E-900 (a distributed-memory parallel computer with 692(More)
Characterizing percolation patterns in unsatu-rated fractured rock has posed a greater challenge to modeling investigations than comparable saturated zone studies due to the heterogeneous nature of unsaturated media and the great number of variables impacting unsaturated flow. An integrated modeling methodology has been developed for quantitatively(More)
This paper presents the application of parallel computing techniques to large-scale modeling of fluid flow in the unsaturated zone (UZ) at Yucca Mountain, Nevada. In this study, parallel computing techniques, as implemented into the TOUGH2 code, are applied in large-scale numerical simulations on a distributed-memory parallel computer. The modeling study(More)
The unsaturated fractured volcanic deposits at Yucca Mountain in Nevada, USA, have been intensively investigated as a possible repository site for storing high-level radioactive waste. Field studies at the site have revealed that there exist large variabilities in hydrological parameters over the spatial domain of the mountain. Systematic analyses of(More)
We use the TOUGH+HYDRATE code to assess the production potential of challenging hydrate deposits, i.e., deposits that are characterized by any combination of the following factors: absence of confining boundaries, high thermodynamic stability, low temperatures, low formation permeability. Using high-resolution grids, we show that a new horizontal well(More)
Simulation of the system behavior of hydrate-bearing geologic media involves solving fully coupled mass-and heat-balance equations. In this study, we develop a domain decomposition approach for large-scale gas hydrate simulations with coarse-granularity parallel computation. This approach partitions a simulation domain into small subdomains. The full model(More)
  • Keni Zhang, Yu-Shu Wu, Chris Ding, Karsten Pruess
  • 2001
Even with the continual advances made in both computational algorithms and computer hardware used in reservoir modeling studies, large-scale simulation of fluid and heat flow in heterogeneous reservoirs remains a challenge. The problem commonly arises from intensive computational requirement for detailed modeling investigations of real-world reservoirs.(More)