The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Bjarne A Foss - One of the best experts on this subject based on the ideXlab platform.
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Modeling, Simulation, and Optimal Control of Oil Production under Gas
2020Co-Authors: Agus Hasan, Svein Sagatun, Bjarne A Foss, Bjørn Peter Tjøstheim, Atle Svandal, Cato HatlandAbstract:Gas Coning is a tendency of the Gas to impel the oil downward in an inverse cone contour toward the well perforations. Once the Gas reaches the well, Gas production will dominate the well flow and the oil production will hence significantly decrease. From an economical and operational standpoint this condition is undesirable since the Gas price is much lower than the oil price, and the Gas handling capacity often is a constraint. Therefore, there is an incentive to maximize oil production up until Gas breakthrough. In this paper, the Gas Coning process in a Gas oil reservoir completed with a single horizontal well is analytically modeled, simulated, and analyzed applying a nonlinear control approach. The model which describes the interaction between the well and the reservoir may be cast into a boundary control problem of the porous media equation with two boundary conditions; a Neumann boundary condition describing no flow at the outer boundary of the reservoir, and a nonlinear boundary condition describing the well production rate. A well rate controller for the boundary control problem is designed using the Lyapunov method. The controller holds some formal performance guarantees and requires information on the Gas oil contact at the well heel only. Further, the controller has a tuning parameter which can be used to maximize a suitable performance measure. The controller is evaluated using a detailed ECLIPSE simulator of a Gas Coning reservoir. Simulation results show significant improvement of production profit of the proposed method compared to a conventional method which usually uses a constant rate up until Gas breakthrough.
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Dantzig-Wolfe decomposition for real-time optimization - applied to the Troll west oil rim
IFAC Proceedings Volumes, 2020Co-Authors: Vidar Gunnerud, Bjarne A Foss, Bjørn Nygreen, Randi Vestbø, Nina C. WalbergAbstract:Abstract Abstract This paper studies different decomposition approaches for real-time optimization of process systems with a decentralized structure where the idea is to improve computational efficiency and transparency of a solution. The contribution lies in the application and assessment of the Dantzig-Wolfe method which allows us to efficiently decompose a real-time optimization problem into parts. Furthermore, the nonlinear system is modeled by piecewise linear models with the added benefit that error bounds on the solution can be computed. The merits of the method are studied by applying it to a semi-realistic model of the Troll west oil rim, a petroleum asset with severe production optimization challenges due to rate dependent Gas-Coning wells. This study indicates that the Dantzig-Wolfe approach offers an interesting and robust option for complex production systems. Moreover, the method compares favourable with earlier results using Lagrangian relaxation which again was favourable compared to a global approach.
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optimization of oil production under Gas Coning conditions
Journal of Petroleum Science and Engineering, 2013Co-Authors: Agus Hasan, Svein Sagatun, Bjarne A FossAbstract:Abstract Typically, a well is produced with a constant oil rate with constant Gas–oil ratio (GOR) during the subcritical phase, i.e. before Gas breakthrough. The presence of Gas Coning in production wells may reduce the oil production. The decline in the oil rate will be followed by an increase in the well head pressure. From an economical and operational point of view, this condition may be undesirable for several reasons; the Gas price is much lower than the oil price, the afflicted well may be abandoned early, and the Gas handling capacity often is a constraint. Therefore, there is an incentive to produce such wells in their subcritical phase for an extended period of time. In this paper, the Gas Coning process in a Gas–oil reservoir completed with a single horizontal well is analytically modeled, simulated, and analyzed applying a nonlinear control approach. The horizontal well model which describes the interaction between the well and the reservoir may be cast into a boundary control problem of the porous media equation with two boundary conditions; a homogeneous Neumann's boundary condition describing no-flow at the outer boundary of the reservoir, and a nonlinear boundary condition describing the well production rate. A well rate controller for the boundary control problem is designed using the backstepping method. The controller holds some formal performance guarantees and requires information on the Gas–oil contact (GOC) at the well heel only. Furthermore, the controller has a tuning parameter which can be used to maximize a suitable performance measure, e.g. the net present value (NPV). The controller is evaluated using a detailed Eclipse simulator of a Gas Coning reservoir. Simulation results show significant improvement of production profit of the proposed method compared to a conventional method which usually uses a constant rate until Gas breakthrough.
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Oil production optimization solved by piecewise linearization in a Branch & Price framework
Computers & Operations Research, 2012Co-Authors: Vidar Gunnerud, Bjarne A Foss, K. I. M. Mckinnon, Bjørn NygreenAbstract:This paper presents a method for optimizing oil production on large scale production networks such as the Troll west field in the North Sea. The method is based on piecewise linearization of all nonlinearities, and on decomposition of the full scale problem into smaller subproblems. Column generation in a Branch & Price framework is used to solve the decomposed problem. The method differs from most Branch & Price methods by branching only on continuous quantities and by solving the subproblems using commercial MILP software. The method is applied to a realistic model of an oil field, the Troll oil and Gas field at the Norwegian Continental Shelf, a petroleum asset with severe production optimization challenges due to rate dependent Gas-Coning wells. This study shows that the method is capable of solving instances of practical size to proven optimality.
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CDC - Well rate control design for Gas Coning problems
49th IEEE Conference on Decision and Control (CDC), 2010Co-Authors: Agus Hasan, Svein Sagatun, Bjarne A FossAbstract:This paper presents a method which uses boundary control to increase the oil production in the subcritical phase of a thin oil rim reservoir which is drained via horizontal wells. The problem of finding an optimal well rate is considered using the backstepping method. The feedback control law is constructed explicitly and together with a reservoir-well simulator are used to generate a time varying production plan. The simulation result shows that the performance of the active control law is much better than conventional production strategies using constant oil rates until Gas breakthrough.
A Hill - One of the best experts on this subject based on the ideXlab platform.
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a multi disciplinary approach to horizontal well planning in the prudhoe bay field alaska
AAPG Bulletin, 1993Co-Authors: J S Isby, D B Robertson, R H Mays, S. Anderson, A HillAbstract:A recently drilled horizontal well in the Prudhoe Bay Field, the F-47, was a success due to multi-disciplinary planning. An integrated team effort that incorporated geology, geophysics, petrophysics, reservoir engineering, production engineering and drilling engineering evaluated the target area. planned and drilled the well. This well targeted a thin wedge of oil at the base of the Ivishak Formation, the main Prudhoe Bay reservoir. The objective section is within the deltaic portion of the reservoir and is characterized by a low KV/KH reservoir; fine-grained sandstone through siltstone with numerous shale layers of varying continuity interspersed. The objective section is bound on top by a relatively continuous shale layer that serves as a barrier to Gas Coning from the overlying Gas-oil contact within the fluvial portion of the reservoir. The lower boundary is a layer of heavy oil/tar below which lies the aquifer. The drilling strategy involved placing the well toward the base of the reservoir, to maximize standoff from the overlying Gas and facilitate maximum drainage of the light oil column. The well was deliberately drilled across two faults. The wellbore penetrated the heavy oil/tar layer to define the base of the reservoir section, inverted and flattended out to maximizemore » standoff, and then climbed structure as it crossed the two faults - from hanging wall to foot wall in both cases, to penetrate the best quality reservoir. The completion involved a fully cemented and perforated liner in the horizontal section. Initial flow rate after cleanup was 4300 bbl of oil/day at low Gas/oil ratio and water cut.« less
Vidar Gunnerud - One of the best experts on this subject based on the ideXlab platform.
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Dantzig-Wolfe decomposition for real-time optimization - applied to the Troll west oil rim
IFAC Proceedings Volumes, 2020Co-Authors: Vidar Gunnerud, Bjarne A Foss, Bjørn Nygreen, Randi Vestbø, Nina C. WalbergAbstract:Abstract Abstract This paper studies different decomposition approaches for real-time optimization of process systems with a decentralized structure where the idea is to improve computational efficiency and transparency of a solution. The contribution lies in the application and assessment of the Dantzig-Wolfe method which allows us to efficiently decompose a real-time optimization problem into parts. Furthermore, the nonlinear system is modeled by piecewise linear models with the added benefit that error bounds on the solution can be computed. The merits of the method are studied by applying it to a semi-realistic model of the Troll west oil rim, a petroleum asset with severe production optimization challenges due to rate dependent Gas-Coning wells. This study indicates that the Dantzig-Wolfe approach offers an interesting and robust option for complex production systems. Moreover, the method compares favourable with earlier results using Lagrangian relaxation which again was favourable compared to a global approach.
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Integrated production optimization of oil fields with pressure and routing constraints: The Urucu field
Computers & Chemical Engineering, 2012Co-Authors: Andrés Codas, Vidar Gunnerud, Sthener R.v. Campos, Eduardo Camponogara, Snjezana SunjergaAbstract:Abstract This paper develops a framework for integrated production optimization of complex oil fields such as Urucu, which has a gathering system with complex routing degree of freedom, limited processing capacity, pressure constraints, and wells with Gas-Coning behavior. The optimization model integrates simplified well deliverability models, vertical lift performance relations, and the flowing pressure behavior of the surface gathering system. The framework relies on analytical models history matched to field data and simulators tuned to reflect operating conditions. A mixed-integer linear programming (MILP) problem is obtained by approximating these models with piecewise-linear functions. Procedures were developed to obtain simplified piecewise-linear approximations that ensure a given accuracy with respect to complex and precise models. Computational experiments showed that the integrated production optimization problem can be solved sufficiently fast for real-time applications. Further, the operational conditions calculated with the simplified models during the optimization process match the precise models.
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Oil production optimization solved by piecewise linearization in a Branch & Price framework
Computers & Operations Research, 2012Co-Authors: Vidar Gunnerud, Bjarne A Foss, K. I. M. Mckinnon, Bjørn NygreenAbstract:This paper presents a method for optimizing oil production on large scale production networks such as the Troll west field in the North Sea. The method is based on piecewise linearization of all nonlinearities, and on decomposition of the full scale problem into smaller subproblems. Column generation in a Branch & Price framework is used to solve the decomposed problem. The method differs from most Branch & Price methods by branching only on continuous quantities and by solving the subproblems using commercial MILP software. The method is applied to a realistic model of an oil field, the Troll oil and Gas field at the Norwegian Continental Shelf, a petroleum asset with severe production optimization challenges due to rate dependent Gas-Coning wells. This study shows that the method is capable of solving instances of practical size to proven optimality.
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Oil production optimization—A piecewise linear model, solved with two decomposition strategies
Computers & Chemical Engineering, 2010Co-Authors: Vidar Gunnerud, Bjarne A FossAbstract:This paper presents a new method for real-time optimization of process systems with a decentralized structure where the idea is to improve computational efficiency and transparency of a solution. The contribution lies in the application and assessment of the Lagrange relaxation and the Dantzig–Wolfe methods, which allows us to efficiently decompose a real-time optimization problem. Furthermore, all nonlinearities are modeled by piecewise linear models, resulting in a mixed integer linear program, with the added benefit that error bounds on the solution can be computed. The merits of the method are studied by applying it to a semi-realistic model of the Troll west oil rim, a petroleum asset with severe production optimization challenges due to rate dependent Gas-Coning wells. This study indicates that both the Lagrange relaxation and in particular the Dantzig–Wolfe approach offers an interesting option for complex production systems. Moreover, the method compares favorably with the non-decomposed method.
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Parallel Dantzig–Wolfe decomposition for real-time optimization—Applied to a complex oil field
Journal of Process Control, 2010Co-Authors: Vidar Gunnerud, Bjarne A Foss, Erlend TorgnesAbstract:Abstract This paper studies Dantzig–Wolfe decomposition for real-time optimization of process systems with a decentralized structure. The idea is to improve computational efficiency and transparency of a solution. The contribution lies in the application of the Dantzig–Wolfe method which allows us to efficiently decompose an optimization problem into parts. Moreover, we show how the algorithm can be parallelized for even higher efficiency. The nonlinear system is modeled by piecewise linear models with the added benefit that error bounds can be computed. In this context alternative parameterizations are discussed. The properties of the method are studied by applying it to a model of a complex petroleum field with severe production optimization challenges due to rate dependent Gas-Coning wells. The model resembles the Troll west oil rim, a huge Gas and oil field on the Norwegian Continental shelf. Finally, the paper discusses workflows in production optimization as a means to explain how the proposed methodology can be applied in practice.
James J Hickey - One of the best experts on this subject based on the ideXlab platform.
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permeability characterization of distributary mouth bar sandstones in prudhoe bay field alaska how horizontal cores reduce risk in developing deltaic reservoirs
AAPG Bulletin, 2001Co-Authors: James J HickeyAbstract:Oil production from upstructure drill sites at Prudhoe Bay field, Alaska, is almost exclusively from fine-grained deltaic sandstones. Distributary channel and distributary mouth bar facies associations in the Triassic Ivishak Formation comprise the pay zones, but wells are preferentially completed in the lower-permeability distributary mouth bar deposits in an attempt to avoid high Gas/oil ratio wells. Thin light-oil columns combined with complex stratigraphy and an overlying, highly mobile Gas cap make planning, drilling, and completing economic wells challenging. To accurately assess lateral trends in permeability within distributary mouth bar sandstones, three conventional cores were cut (approximately 120 ft [36 m]) along the 1000 ft (304 m) horizontal reach of a recent development well. The cored interval consists of seven lithofacies, all composed of fine-grained sandstone. Comparison of permeability values to lithofacies demonstrates a striking and consistent trend. Six lithofacies possess average horizontal permeabilities ranging from 12 to 40 md. Average horizontal permeability for the seventh lithofacies (lithofacies 7) is 129 md. Porosity and vertical permeability follow similar patterns. Distributary mouth bars in Prudhoe Bay field were deposited in fluvially dominated delta lobes in which sediment distribution at river mouths was controlled by friction between the sediment plume and basin bottom. During flood stage, the best sorted and most permeable sediments (i.e., lithofacies 7) were deposited on the apex or most proximal part of the distributary mouth bars between distributary channels. Sedimentologic and petrographic data corroborate a strong link between lithofacies and permeability. Sandstones deposited by unsteady flow conditions (e.g., turbulent (Begin page 460) scour, intermittent ripple migration) are likely to be less well sorted, and contain more clay and lignitic organic material (commonly as drapes and wisps), than lithofacies 7 sandstones deposited under more uniform high-energy transport conditions. Small amounts of argillaceous and lignitic laminae serve as nucleation sites for siderite cement precipitation and as catalysts for pressure solution of quartz grains, significantly degrading permeability in lithofacies 1 through 6. Insights gained from analyzing these cores can reduce the risks associated with well completions in distributary mouth bar sandstones. Locations targeting distributary mouth bar deposits can be optimized by (1) using existing well data to map time-equivalent deltaic facies associations; (2) identifying transition zones between distributary channels and distributary mouth bars; (3) extrapolating trends of high-permeability lithofacies within distributary mouth bars; and (4) calculating the well trajectory and length, to optimally contact high-permeability rock (or moderate-permeability rock to inhibit Gas Coning).
J S Isby - One of the best experts on this subject based on the ideXlab platform.
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a multi disciplinary approach to horizontal well planning in the prudhoe bay field alaska
AAPG Bulletin, 1993Co-Authors: J S Isby, D B Robertson, R H Mays, S. Anderson, A HillAbstract:A recently drilled horizontal well in the Prudhoe Bay Field, the F-47, was a success due to multi-disciplinary planning. An integrated team effort that incorporated geology, geophysics, petrophysics, reservoir engineering, production engineering and drilling engineering evaluated the target area. planned and drilled the well. This well targeted a thin wedge of oil at the base of the Ivishak Formation, the main Prudhoe Bay reservoir. The objective section is within the deltaic portion of the reservoir and is characterized by a low KV/KH reservoir; fine-grained sandstone through siltstone with numerous shale layers of varying continuity interspersed. The objective section is bound on top by a relatively continuous shale layer that serves as a barrier to Gas Coning from the overlying Gas-oil contact within the fluvial portion of the reservoir. The lower boundary is a layer of heavy oil/tar below which lies the aquifer. The drilling strategy involved placing the well toward the base of the reservoir, to maximize standoff from the overlying Gas and facilitate maximum drainage of the light oil column. The well was deliberately drilled across two faults. The wellbore penetrated the heavy oil/tar layer to define the base of the reservoir section, inverted and flattended out to maximizemore » standoff, and then climbed structure as it crossed the two faults - from hanging wall to foot wall in both cases, to penetrate the best quality reservoir. The completion involved a fully cemented and perforated liner in the horizontal section. Initial flow rate after cleanup was 4300 bbl of oil/day at low Gas/oil ratio and water cut.« less
