Sadok Lamine - Academia.edu (original) (raw)

Papers by Sadok Lamine

International Petroleum Technology Conference, 2019

Waterflood (WF) is the main drive mechanism of North Kuwait reservoirs. Different development str... more Waterflood (WF) is the main drive mechanism of North Kuwait reservoirs. Different development strategies has been adopted to develop a giant carbonate reservoir in the asset. Irregular scheme of WF has been implemented in the last 5 years which made it challenging to properly evaluate the WF performance. This paper presents both numerical and analytical approaches to assess the current performance of the waterflood in this reservoir. The first method uses actual production and injection data to generate traditional waterflood plots such WOR vs. Np, injection throughput, VRR and other diagnostics. The second approach uses the numerical model to understand the fluid movements in terms of production and water injection. A high resolution model is used to know about the horizontal producers and injectors WF scheme. Streamline model tool is used to understand how the injectors impact their surrounding producers. Injector's efficiency, allocation factors and reservoir sweep efficiency are calculated using the simulation model. Both approaches are compared to have a better evaluation of the waterflood. When the waterflood started, a regular i-9 spot patterns was the way to develop the reservoir. The heterogeneity of the reservoir was observed clearly in the different performance of each pattern. Also, high permeability layer (thief zone) has adversely affected the reservoir performance during WF. The sharp increase of water cut with very low corresponding recovery factor triggered a paradigm shift in developing this waterflooded reservoir. Injecting in lower layers and producing in upper layers (horizontal wells) was the next stage. This brought a great challenge to assess the performance of this WF scheme. Evaluating such a development strategy remains a achallenge.

SEG Technical Program Expanded Abstracts 2017, 2017

swansea.academia.edu

Discontinuous-Galerkin schemes are presented for convective flow approximation in reservoir simul... more Discontinuous-Galerkin schemes are presented for convective flow approximation in reservoir simulation. The methods are compared with slope limited MUSCL and TVD schemes. Standard reservoir simulation schemes employ single-point upstream weighting (first order upwind) for approximation of the convective fluxes when multiple phases or components are present. Higher order upwind approximations have also been developed, including higher order Godunov schemes. These schemes require a characteristic decomposition when applied to hyperbolic systems with multiple phases or components present. The decomposition leads to optimal upwind schemes where upwind directions are resolved according to characteristic wave components. However the decomposition adds further complexity and additional computation is required to account for the decomposition matrices. This paper presents novel Discontinuous-Galerkin schemes for reservoir simulation that permit reconstruction of stable higher order monotonicity preserving approximations while avoiding dependence upon both upwinding and characteristic decomposition. The schemes are formulated within a locally conservative finite volume framework. Results are presented for gravity driven flows, where the wave direction changes sign (reverse flow). Results obtained with the new schemes indicate a competitive comparison with the other higher order schemes.

Summary The North Kuwait Carbonate (NKJG) reservoirs are currently under development by KOC (Kuwa... more Summary The North Kuwait Carbonate (NKJG) reservoirs are currently under development by KOC (Kuwait Oil Company). The appraisal and development of the NKJG offer challenges such as lateral variations in reservoir quality, tight to very tight reservoirs and natural fracturing to a varying degree spatially. The presence of open and connected fractures is one of the key elements to achieve a successful development. Also, the presence of fracture corridors increase the risk associated with drilling. Numerous fracture modelling studies have been supporting both appraisal and development strategies of the fields. A structural evolution model has been developed based on field observations and linked to the regional phases of deformations. Detailed fracture characterization using static BHI (bore hole images) and core data as well as dynamic data has been carried. A wide spectrum of scales of discrete fracture network (DFN) models have been built. The smaller scale models have supported the...

Day 3 Wed, November 15, 2017, 2017

The North Kuwait Carbonate (NKJG) reservoirs are currently under development by KOC (Kuwait Oil C... more The North Kuwait Carbonate (NKJG) reservoirs are currently under development by KOC (Kuwait Oil Company). The appraisal and development of the NKJG offer challenges such as lateral variations in reservoir quality, tight to very tight reservoirs and natural fracturing to a varying degree spatially. The presence of open, connected fractures is one of the key elements to achieve a successful development. Also, the presence of fracture corridors increase the risk associated with drilling. Numerous fracture modelling studies have been supporting both appraisal and development strategies of the fields.A structural evolution model has been developed based on field observations and linked to the regional phases of deformations. Detailed fracture characterization using static BHI (bore hole images) and core data as well as dynamic data has been achieved. Small scale detailed DFN (Discrete Fracture Network) in support of planning and drilling activities of future appraisal wells has been carr...

Day 3 Wed, November 15, 2017, 2017

The North Kuwait Carbonate (NKJG) reservoirs are currently under development by KOC (Kuwait Oil C... more The North Kuwait Carbonate (NKJG) reservoirs are currently under development by KOC (Kuwait Oil Company). In addition to the matrix heterogeneity, natural fracturing poses extra challenges for the optimization of the field development planning. The presence of open, connected fractures presents opportunities for infill drilling but increases the risk of water invasion and drilling related issues. Numerous fracture modelling studies have been supporting both appraisal and development strategies of the fields. The translation of the field observation and detailed fracture characterization using static BHI (bore hole image) and core data yields a series of geological concepts. These concepts capture end members of the spatial distribution of the major conductive features and provide a range of realizations for the geometrical extent of the fracture zones. Given the large uncertainty in the dynamic properties of the fracture; pressure transient analysis (PTA), complemented by core data,...

Proceedings, 2013

ABSTRACT For dynamic simulations on a fractured reservoir it is often necessary to translate a di... more ABSTRACT For dynamic simulations on a fractured reservoir it is often necessary to translate a discrete fracture network (DFN) model into a grid-based set of effective properties. During this upscaling step, the critical characteristics of the original fracture network must be preserved to ensure that the previously performed fracture characterisation and modelling work is not compromised. The ultimate goal is to represent geologically sound fracture scenarios in simulation models so that the impact on fluid flow, well rates and development decisions can be tested. Different methodologies have been proposed and were incorporated into commercial fracture modelling packages to perform this translation. However, each method comes with its own set of advantages and disadvantages and none reliably preserves the connectivity of a given fracture network on the scale of a full field model. We will present tools developed in the Shell in-house fracture modelling software SVS Fracture Solutions to upscale a DFN and to quality check the resulting effective property grid. We will outline a workflow that ensures the preservation of the most important characteristic of a DFN, i.e., its connectivity, and which reliably works on full field models.

Standard reservoir simulation schemes employ single-point upstream weighting for approximation of... more Standard reservoir simulation schemes employ single-point upstream weighting for approximation of the convective fluxes when multiple phases or components are present. These schemes introduce both coordinate-line numerical diffusion and crosswind diffusion into the solution that is grid and geometry dependent. Families of locally conservative higher-order multidimensional upwind schemes are presented for convective flow approximation in porous media that reduce both directional and crosswind diffusion. The schemes are coupled with full-tensor Darcy flux approximations and handle general flow conditions including counter current gravity driven flows and systems of hyperbolic equations. Characteristic vector upwind approximations are proposed and compared with the simulation standard single-point upstream weighting schemes. When dealing with systems of hyperbolic equations, upwind characteristic wave decomposition is used in combination with different limiting strategies involving con...

Multiscale Modeling & Simulation, 2016

This paper presents the development of finite-volume multiscale methods for quadrilateral and tri... more This paper presents the development of finite-volume multiscale methods for quadrilateral and triangular unstructured grids. Families of Darcy-flux approximations have been developed for consistent approximation of the general tensor pressure equation arising from Darcy's law together with mass conservation. The schemes are control-volume distributed (CVD) with flow variables and rock properties sharing the same control-volume location and are comprised of a multipoint flux family formulation (CVD-MPFA). The schemes are used to develop a CVD-MPFA based multiscale finite-volume (MSFV) formulation applicable to both structured and unstructured grids in twodimensions. The basis functions are a key component of the MSFV method, and are a set of local solutions, usually defined subject to Dirichlet boundary conditions. A generalisation of the Cartesian grid Dirichlet basis functions described in [20] is presented here for unstructured grids. Whilst the transition from a Cartesian grid to an unstructured grid is largely successful, use of Dirichlet basis functions can still lead to pressure fields that exhibit spurious oscillations in areas of strong heterogeneity. New basis functions are proposed in an attempt to improve the pressure field solutions where Neumann boundary conditions are imposed almost every where, except corners which remain specified by Dirichlet values.

Computer Methods in Applied Mechanics and Engineering, 2015

upwind schemes and higher resolution methods for three-component twophase systems including gravi... more upwind schemes and higher resolution methods for three-component twophase systems including gravity driven flow in porous media on unstructured grids. Computer Methods in Applied Mechanics and Engineering

$Research paper thumbnail of CVD-MPFA full pressure support, coupled unstructured discrete fracture–matrix Darcy-flux approximations$

Journal of Computational Physics, 2017

Two novel control-volume methods are presented for flow in fractured media, and involve coupling ... more Two novel control-volume methods are presented for flow in fractured media, and involve coupling the controlvolume distributed multi-point flux approximation (CVD-MPFA) constructed with full pressure support (FPS), to two types of discrete fracture-matrix approximation for simulation on unstructured grids; (i) involving hybrid grids and (ii) a lower dimensional fracture model. Flow is governed by Darcy's law together with mass conservation both in the matrix and the fractures, where large discontinuities in permeability tensors can occur. Finite-volume FPS schemes are more robust than the earlier CVD-MPFA triangular pressure support (TPS) schemes for problems involving highly anisotropic homogeneous and heterogeneous full-tensor permeability fields. We use a cell-centred hybrid-grid method, where fractures are modelled by lower-dimensional interfaces between matrix cells in the physical mesh but expanded to equi-dimensional cells in the computational domain. We present a simple procedure to form a consistent hybrid-grid locally for a dual-cell. We also propose a novel hybrid-grid for intersecting fractures, for the FPS method, which reduces the condition number of the global linear system and leads to larger time steps for tracer transport. The transport equation for tracer flow is coupled with the pressure equation and provides flow parameter assessment of the fracture models. Transport results obtained via TPS and FPS hybrid-grid formulations are compared with the corresponding results of fine-scale explicit equi-dimensional formulations. The results show that the hybrid-grid FPS method applies to general full-tensor fields and provides improved robust approximations compared to the hybrid-grid TPS method for fractured domains, for both weakly anisotropic permeability fields and very strong anisotropic full-tensor permeability fields where the TPS scheme exhibits spurious oscillations. The hybrid-grid FPS formulation is extended to compressible flow and the results demonstrate the method is also robust for transient flow. Furthermore, we present FPS coupled with a lower-dimensional fracture model, where fractures are strictly lower-dimensional in the physical mesh as well as in the computational domain. We present a comparison of the hybrid-grid FPS method and the lower-dimensional fracture model for several cases of isotropic and anisotropic fractured media which illustrate the benefits of the respective methods.

$Research paper thumbnail of CVD-MPFA Full Pressure Support Scheme for Discrete-fracture Matrix Simulations on Unstructured Grids$

Proceedings, 2016

We investigate cell-centred finite-volume, control-volume distributed multipoint flux approximati... more We investigate cell-centred finite-volume, control-volume distributed multipoint flux approximation (CVD-MPFA), with full pressure support (FPS), for discrete-fractures on unstructured grids. Fractures are modelled by lower-dimensional interfaces between matrix cells in the physical mesh but expanded to equi-dimensional cells in the computational domain; known as the hybrid-grid method. We present a simple process to form a precise hybrid-grid locally for a dual-cell. We also present a novel robust method for intersecting fractures, for FPS method, which reduces the condition number of the global linear system and leads to larger time steps for tracer transport. TPS and FPS hybrid-grid formulations are compared with corresponding fine-scale explicit equi-dimensional formulations. The results show that the FPS scheme provides robust and improved approximations for weakly anisotropic fields compared to the TPS scheme. The FPS hybrid-grid method is also beneficial for fractured domains with very strong anisotropic full-tensor permeability fields where the TPS scheme exhibits spurious oscillations. Furthermore, we present FPS coupled with a lower-dimensional fracture model, where fractures are strictly lower-dimensional in the physical mesh as well as in the computational domain. We present a comparison of the hybrid-grid FPS method and the lower-dimensional fracture model for several cases of isotropic and anisotropic fractured media.

ECMOR XIII - 13th European Conference on the Mathematics of Oil Recovery, Sep 10, 2012

Subsurface reservoirs generally have a complex description in terms of both geometry and geology.... more Subsurface reservoirs generally have a complex description in terms of both geometry and geology. This poses a continuing challenge in modelling and simulation of reservoirs due to variations at different length scales. Multiscale simulation is a new and promising approach that enables simulation of detailed geological model and the retention of level of detail and heterogeneity that would not be possible via conventional upscaling methods. Most multiscale methods are developed from a sequential formulation, in which flow (pressure-flux) and transport (saturation) equations are solved in separate steps. The flow equation is solved using a set of special multiscale basis functions that attempt to incorporate the effects of sub-grid geological heterogeneity into a global flow equation formulated on a coarsened grid. The multiscale basis functions are computed numerically by solving local flow problems, and can be used to construct conservative fluxes on the coarsened as well as the original fine grid. Herein, we consider one particular multiscale method, the multiscale mixed finite-element method, and discuss how it can be extended to account for capillary pressure effects. The method is evaluated for computational efficiency and accuracy on a series of models with a high degree of realism, including spatially dependent relative permeability and capillary effects, gravity, and highly heterogeneous rock properties specified on representative corner-point grids.

ECMOR X - 10th European Conference on the Mathematics of Oil Recovery, 2006

Novel high resolution schemes for convective flow approximation are developed and coupled with ge... more Novel high resolution schemes for convective flow approximation are developed and coupled with general continuous full-tensor Darcy flux approximations. This development leads to new locally conservative formulations for multiphase flow in porous media. The higher order schemes are designed for fluid transport on unstructured grids and are constructed using slope limiters such that they are stable with a maximum principle that ensures solutions are free of spurious oscillations. The schemes are developed to handle unstructured meshes with variable grid spacing and different formulations are compared. Benefits of the resulting schemes are demonstrated for classical test problems in reservoir simulation including cases with full tensor permeability fields. The test cases involve a range of unstructured grids with variations in grid spacing, orientation and permeability that lead to flow fields that are poorly resolved by standard simulation methods. The new formulation is compared with standard reservoir simulation schemes and control-volume finite element methods. The new schemes are shown to effectively reduce numerical diffusion while resolving flow induced by rapid changes in permeability, leading to superior resolution of concentration and saturation fronts compared to other schemes.

$Research paper thumbnail of Three-dimensional control-volume distributed multi-point flux approximation coupled with a lower-dimensional surface fracture model$

Journal of Computational Physics, 2015

A novel cell-centred control-volume distributed multi-point flux approximation (CVD-MPFA) finite-... more A novel cell-centred control-volume distributed multi-point flux approximation (CVD-MPFA) finite-volume formulation is presented for discrete fracture-matrix simulations on unstructured grids in three-dimensions (3D). The grid is aligned with fractures and barriers which are then modelled as lower-dimensional surface interfaces located between the matrix cells in the physical domain. The three-dimensional pressure equation is solved in the matrix domain coupled with a two-dimensional (2D) surface pressure equation solved over fracture networks via a novel surface CVD-MPFA formulation. The CVD-MPFA formulation naturally handles fractures with anisotropic permeabilities on unstructured grids. Matrix-fracture fluxes are expressed in terms of matrix and fracture pressures and define the transfer function, which is added to the lowerdimensional flow equation and couples the three-dimensional and surface systems. An additional transmission condition is used between matrix cells adjacent to low permeable fractures to couple the velocity and pressure jump across the fractures. Convergence and accuracy of the lower-dimensional fracture model is assessed for highly anisotropic fractures having a range of apertures and permeability tensors. A transport equation for tracer flow is coupled via the Darcy flux for single and intersecting fractures. The lower-dimensional approximation for intersecting fractures avoids the more restrictive CFL condition corresponding to the equi-dimensional approximation with explicit time discretisation. Lower-dimensional fracture model results are compared with equi-dimensional model results. Fractures and barriers are efficiently modelled by lowerdimensional interfaces which yield comparable results to those of the equi-dimensional model. Pressure continuity is built into the model across highly conductive fractures, leading to reduced local degrees of freedom in the CVD-MPFA approximation. The formulation is applied to geologically complex fracture networks in three-dimensions. The effects of the fracture permeability, aperture and grid resolution are also assessed with respect to convergence and computational cost.

International Journal for Numerical Methods in Fluids, 2014

Subsurface reservoirs generally have a complex description in terms of both geometry and geology.... more Subsurface reservoirs generally have a complex description in terms of both geometry and geology. This poses a continuing challenge in modeling and simulation of petroleum reservoirs due to variations of static and dynamic properties at different length scales. Multiscale methods constitute a promising approach that enables efficient simulation of geological models while retaining a level of detail in heterogeneity that would not be possible via conventional upscaling methods. Multiscale methods developed to solve coupled flow equations for reservoir simulation are based on a hierarchical strategy in which the pressure equation is solved on a coarsened grid and the transport equation is solved on the fine grid, and the two equations are treated as a decoupled system. In particular, the multiscale mixed finite-element (MsMFE) method attempts to capture sub-grid geological heterogeneity directly into the coarse-scale equations via a set of numerically computed basis functions. These basis functions are able to capture the predominant multiscale information and are coupled through a global formulation to provide good approximation of the subsurface flow solution. In the literature, the general formulation of the MsMFE method for incompressible two-phase and compressible three-phase flow has mainly addressed problems with idealized flow physics. In this paper, we first outline a recent formulation that accounts for compressibility, gravity, and spatially-dependent rockfluid parameters. Then, we validate the method by evaluating its computational efficiency and accuracy on a series of representative benchmark tests that have a high degree of realism with respect to flow physics, heterogeneity in the petrophysical models, and geometry/topology of the corner-point grids. In particular, the MsMFE method is validated and compared against an industry-standard fine-scale solver. The fine-scale flux, pressure, and saturation fields computed by the multiscale simulation show a noteworthy improvement in resolution and accuracy compared with coarse-scale models.

ECMOR XIV - 14th European conference on the mathematics of oil recovery, 2014

International Petroleum Technology Conference, 2019

SEG Technical Program Expanded Abstracts 2017, 2017

swansea.academia.edu

Day 3 Wed, November 15, 2017, 2017

The North Kuwait Carbonate (NKJG) reservoirs are currently under development by KOC (Kuwait Oil C... more The North Kuwait Carbonate (NKJG) reservoirs are currently under development by KOC (Kuwait Oil Company). In addition to the matrix heterogeneity, natural fracturing poses extra challenges for the optimization of the field development planning. The presence of open, connected fractures presents opportunities for infill drilling but increases the risk of water invasion and drilling related issues. Numerous fracture modelling studies have been supporting both appraisal and development strategies of the fields. The translation of the field observation and detailed fracture characterization using static BHI (bore hole image) and core data yields a series of geological concepts. These concepts capture end members of the spatial distribution of the major conductive features and provide a range of realizations for the geometrical extent of the fracture zones. Given the large uncertainty in the dynamic properties of the fracture; pressure transient analysis (PTA), complemented by core data,...

Proceedings, 2013

Multiscale Modeling & Simulation, 2016

Computer Methods in Applied Mechanics and Engineering, 2015

$Research paper thumbnail of CVD-MPFA full pressure support, coupled unstructured discrete fracture–matrix Darcy-flux approximations$

Journal of Computational Physics, 2017

$Research paper thumbnail of CVD-MPFA Full Pressure Support Scheme for Discrete-fracture Matrix Simulations on Unstructured Grids$

Proceedings, 2016

ECMOR XIII - 13th European Conference on the Mathematics of Oil Recovery, Sep 10, 2012

ECMOR X - 10th European Conference on the Mathematics of Oil Recovery, 2006

$Research paper thumbnail of Three-dimensional control-volume distributed multi-point flux approximation coupled with a lower-dimensional surface fracture model$

Journal of Computational Physics, 2015

International Journal for Numerical Methods in Fluids, 2014

Subsurface reservoirs generally have a complex description in terms of both geometry and geology.... more Subsurface reservoirs generally have a complex description in terms of both geometry and geology. This poses a continuing challenge in modeling and simulation of petroleum reservoirs due to variations of static and dynamic properties at different length scales. Multiscale methods constitute a promising approach that enables efficient simulation of geological models while retaining a level of detail in heterogeneity that would not be possible via conventional upscaling methods. Multiscale methods developed to solve coupled flow equations for reservoir simulation are based on a hierarchical strategy in which the pressure equation is solved on a coarsened grid and the transport equation is solved on the fine grid, and the two equations are treated as a decoupled system. In particular, the multiscale mixed finite-element (MsMFE) method attempts to capture sub-grid geological heterogeneity directly into the coarse-scale equations via a set of numerically computed basis functions. These basis functions are able to capture the predominant multiscale information and are coupled through a global formulation to provide good approximation of the subsurface flow solution. In the literature, the general formulation of the MsMFE method for incompressible two-phase and compressible three-phase flow has mainly addressed problems with idealized flow physics. In this paper, we first outline a recent formulation that accounts for compressibility, gravity, and spatially-dependent rockfluid parameters. Then, we validate the method by evaluating its computational efficiency and accuracy on a series of representative benchmark tests that have a high degree of realism with respect to flow physics, heterogeneity in the petrophysical models, and geometry/topology of the corner-point grids. In particular, the MsMFE method is validated and compared against an industry-standard fine-scale solver. The fine-scale flux, pressure, and saturation fields computed by the multiscale simulation show a noteworthy improvement in resolution and accuracy compared with coarse-scale models.

ECMOR XIV - 14th European conference on the mathematics of oil recovery, 2014