Coupled Geomechanics and Flow Simulation on Corner-Point and Polyhedral Grids

2017 ◽  
Author(s):  
Odd Andersen ◽  
Halvor MøII Nilsen ◽  
Xavier Raynaud
Keyword(s):  
Corner Point ◽  
Flow Simulation ◽  
Coupled Geomechanics

Accurate Multi-Phase Flow Simulation in Faulted Reservoirs Using Mimetic Finite Difference Methods on Polyhedral Cells

2021 ◽  
Author(s):  
Rencheng Dong ◽  
Faruk O. Alpak ◽  
Mary F. Wheeler
Keyword(s):  
Hybrid Method ◽  
Corner Point ◽  
Flow Simulation ◽  
Phase Flow ◽  
Reference Solution ◽  
Pressure Equation ◽  
Discretization Methods ◽  
Multi Phase Flow ◽  
Polyhedral Cells ◽  
Multi Phase

Abstract Faulted reservoirs are commonly modeled by corner-point grids. Since the two-point flux approximation (TPFA) method is not consistent on non-orthogonal grids, multi-phase flow simulation using TPFA on corner-point grids may have significant discretization errors if grids are not K-orthogonal. To improve the simulation accuracy, we developed a novel method where the faults are modeled by polyhedral cells, and mimetic finite difference (MFD) methods are used to solve flow equations. We use a cut-cell approach to build the mesh for faulted reservoirs. A regular orthogonal grid is first constructed,and then fault planes are added by dividing cells at fault planes. Most cells remain orthogonal while irregular non-orthogonal polyhedral cells can be formed with multiple cell divisions. We investigated three spatial discretization methods for solving the pressure equation on general polyhedral grids, including the TPFA, MFD and TPFA-MFD hybrid methods. In the TPFA-MFD hybrid method, the MFD method is only applied to part of the domain while the TPFA method is applied to rest of the domain. We compared flux accuracy between TPFA and MFD methods by solving a single-phase flow problem. The reference solution is obtained on a rectangular grid while the same problem is solved by TPFA and MFD methods on a grid with distorted cells near a fault. Fluxes computed using TPFA exhibit larger errors in the vicinity of the fault while fluxes computed using MFD are still as accurate as the reference solution. We also compared saturation accuracy of two-phase (oil and water) flow in faulted reservoirs when the pressure equation is solved by different discretization methods. Compared with the reference saturation solution, saturation exhibits non-physical errors near the fault when pressure equation is solved by the TPFA method. Since the MFD method yields accurate fluxes over general polyhedral grids, the resulting saturation solutions match the reference saturation solutions with an enhanced accuracy when the pressure equation is solved by the MFD method. Based on the results of our simulation studies, the accuracy of the TPFA-MFD hybrid method is very close to the accuracy of the MFD method while the TPFA-MFD hybrid method is computationally cheaper than the MFD method.

scholarly journals Semi-Implicit Finite Volume Procedure for Compositional Subsurface Flow Simulation in Highly Anisotropic Porous Media

Fluids ◽  
2021 ◽  
Vol 6 (10) ◽  
pp. 341
Author(s):  
Sebastián Echavarría-Montaña ◽  
Steven Velásquez ◽  
Nicolás Bueno ◽  
Juan David Valencia ◽  
Hillmert Alexander Solano ◽  
...  
Keyword(s):  
Porous Media ◽  
Corner Point ◽  
Subsurface Flow ◽  
Flow Simulation ◽  
Oil Field ◽  
Flow In Porous Media ◽  
Anisotropic Porous Media ◽  
Compositional Flow ◽  
Newton Raphson ◽  
Raphson Method

Subsurface multiphase flow in porous media simulation is extensively used in many disciplines. Large meshes with non-orthogonalities (e.g., corner point geometries) and full tensor highly anisotropy ratios are usually required for subsurface flow applications. Nonetheless, simulations using two-point flux approximations (TPFA) fail to accurately calculate fluxes in these types of meshes. Several simulators account for non-orthogonal meshes, but their discretization method is usually non-conservative. In this work, we propose a semi-implicit procedure for general compositional flow simulation in highly anisotropic porous media as an extension of TPFA. This procedure accounts for non-orthogonalities by adding corrections to residual in the Newton-Raphson method. Our semi-implicit formulation poses the guideline for FlowTraM (Flow and Transport Modeller ) implementation for research and industry subsurface purposes. We validated FlowTraM with a non-orthogonal variation of the Third SPE Comparative Solution Project case. Our model is used to successfully simulating a real Colombian oil field.

Coupled Geomechanics and Flow Simulation for an Embedded Discrete Fracture Model

2013 ◽  
Author(s):  
Ali Moinfar ◽  
Kamy Sepehrnoori ◽  
Russell T. Johns ◽  
Abdoljalil Varavei
Keyword(s):  
Flow Simulation ◽  
Fracture Model ◽  
Discrete Fracture Model ◽  
Discrete Fracture ◽  
Coupled Geomechanics

scholarly journals Dynamic effects of fault modeling on stair-step and corner-point grids

2021 ◽  
Vol 11 (3) ◽  
pp. 1323-1338
Author(s):  
Faruk O. Alpak ◽  
Tianhong Chen
Keyword(s):  
Reservoir Simulation ◽  
Corner Point ◽  
Flow Simulation ◽  
Fault Modeling ◽  
Added Value ◽  
Dynamic Effects ◽  
Flux Approximation ◽  
Grid Convergence ◽  
Simulation Results ◽  
Similar Accuracy

AbstractFault modeling has become an integral element of reservoir simulation for structurally complex reservoirs. Modeling of faults in general has major implications for the simulation grid. In turn, the grid quality control is very important in order to attain accurate simulation results. We investigate the dynamic effects of using stair-step grid (SSG) and corner-point grid (CPG) approaches for fault modeling from the perspective of dynamic reservoir performance forecasting. We have performed a number of grid convergence and grid-type sensitivity studies for a variety of simple, yet intuitive faulted flow simulation problems with gradually increasing complexity. We have also explored the added value of the multipoint flux approximation (MPFA) method over the conventional two-point flux approximation (TPFA) to increase the accuracy of reservoir simulation results obtained on CPGs. Effects of fault seal modeling on grid-resolution convergence and grid-type sensitivity have also been briefly examined. For simple geometries, both SSG and CPG can be used for fault modeling with similar accuracy in conjunction with the pillar-grid approach. This is evidenced by the fact that simulation results from SSG and CPG converge to identical solutions. SSG and CPG yield different results for more complex geometries. Simulation results approach to a converged solution for relatively fine SSGs. However, a SSG only provides an approximation to the fault geometry and reservoir volumes when the grid is coarse. On the other hand, non-orthogonality errors are increasingly evident in relatively more complex faulted models on CPGs and such errors cannot be addressed by grid refinement. It has been observed that MPFA partially addresses the discretization errors on non-orthogonal grids but only from the total flux accuracy perspective. However, transport related errors are still evident. Grid convergence behaviors and grid effects are quite similar with or without fault seal modeling (i.e., dedicated fault-zone modeling by use of scaled-up seal factors) for simple geometries. However, in more complex test cases, we have observed that it is more difficult to achieve converged results in conjunction with fault seal modeling due to increased heterogeneity of the underlying problem.

Coupled geomechanics and flow simulation for time‐lapse seismic modeling

1999 ◽  
Author(s):  
Susan E. Minkoff ◽  
Charles M. Stone ◽  
J. Guadalupe Arguello ◽  
Steve Bryant ◽  
Joe Eaton ◽  
...  
Keyword(s):  
Flow Simulation ◽  
Time Lapse ◽  
Seismic Modeling ◽  
Coupled Geomechanics

Use of Improved Gridding Technique in Coupled Geomechanics and Compositional Reservoir Flow Simulation

2011 ◽  
Author(s):  
Vijay Kumar Shrivastava ◽  
David Tran ◽  
Long X. Nghiem ◽  
Bruce Frederick Kohse
Keyword(s):  
Flow Simulation ◽  
Reservoir Flow ◽  
Coupled Geomechanics

Cold Flow Simulation in Underground Coal Gasification (UCG) Cavities

2014 ◽  
Vol 1 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Dipankar Chatterjee ◽  
◽  
Satish Gupta ◽  
Chebolu Aravind ◽  
Rakesh Roshan
Keyword(s):  
Coal Gasification ◽  
Flow Simulation ◽  
Underground Coal Gasification ◽  
Cold Flow
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