6,166 research outputs found
Impact of anisotropy and fracture density on the approximation of the effective permeability of a fractured rock mass using 2D models
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An exploration of the IGA method for efficient reservoir simulation
Novel numerical methods present exciting opportunities to improve the efficiency of reservoir simulators. Because potentially significant gains to computational speed and
accuracy may be obtained, it is worthwhile explore alternative computational algorithms
for both general and case-by-case application to the discretization of the equations of porous media flow, fluid-structure interaction, and/or production. In the present
work, the fairly new concept of isogeometric analysis (IGA) is evaluated for its suitability
to reservoir simulation via direct comparison with the industry standard finite difference (FD) method and 1st order standard finite element method (SFEM). To this end, two main studies are carried out to observe IGA’s performance with regards to geometrical modeling and ability to capture steep saturation fronts. The first study explores IGA’s ability to model complex reservoir geometries, observing L2 error convergence rates under a variety of refinement schemes. The numerical experimental setup includes an 'S' shaped line sink of varying curvature from which water is produced in a 2D homogenous domain. The accompanying study simplifies the domain to 1D, but adds in multiphase physics that traditionally introduce difficulties associated with modeling of a moving saturation front. Results overall demonstrate promise for the IGA method to be a particularly effective tool in handling geometrically difficult features while also managing typically challenging numerical phenomena.Petroleum and Geosystems Engineerin
Modeling Earthen Dike Stability: Sensitivity Analysis and Automatic Calibration of Diffusivities Based on Live Sensor Data
The paper describes concept and implementation details of integrating a
finite element module for dike stability analysis Virtual Dike into an early
warning system for flood protection. The module operates in real-time mode and
includes fluid and structural sub-models for simulation of porous flow through
the dike and for dike stability analysis. Real-time measurements obtained from
pore pressure sensors are fed into the simulation module, to be compared with
simulated pore pressure dynamics. Implementation of the module has been
performed for a real-world test case - an earthen levee protecting a sea-port
in Groningen, the Netherlands. Sensitivity analysis and calibration of
diffusivities have been performed for tidal fluctuations. An algorithm for
automatic diffusivities calibration for a heterogeneous dike is proposed and
studied. Analytical solutions describing tidal propagation in one-dimensional
saturated aquifer are employed in the algorithm to generate initial estimates
of diffusivities
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