Abstract: Managing oilfield operations include obtaining a subsurface model including a fracture design model having an fracture property with an uncertain value. A set of representative values that represent uncertainty in the fracture property is obtained and used to solve an oilfield optimization problem with a control variable to obtain a solution. The solution includes an optimal value for the control variable. Based on the solution, an oilfield design is generated and stored.

Abstract: A method, apparatus, and computer readable storage medium perform oilfield-wide optimization in a field with a plurality of wells, with each well including a well flow rate management mechanism controlled by an associated well controller. In a central controller, a network simulation model functioning as a proxy of the field is accessed to determine an optimal allocation solution for the field, and a well-specific control signal is generated for each of the plurality of wells based upon the determined optimal allocation solution. The well-specific control signal for each of the plurality of wells is communicated to cause the associated well controller to control a flow rate management parameter associated with the well flow rate management mechanism for the well.

Abstract: A method, apparatus, and program product perform lift optimization in a field with a plurality of wells, with each well including an artificial lift mechanism controlled by an associated well controller. In a central controller, a network simulation model functioning as a proxy of the field is accessed to determine an optimal allocation solution for the field, and a well-specific control signal is generated for each of the plurality of wells based upon the determined optimal allocation solution. The well-specific control signal for each of the plurality of wells is communicated to the associated well controller to cause the associated well controller to control a lift parameter associated with the artificial lift mechanism for the well.

Abstract: A method, apparatus, and program product automatically generate a surface network for an oilfield production system, e.g., as a new surface network or as an addition to an existing surface network. Candidate surface networks are generated from control vectors proposed by an optimization engine to optimize based upon an objective function that is based at least upon one or more geographical cost functions and one or more boundary conditions.

Abstract: A method of optimizing production of wells using choke control includes generating, for each well, an intermediate solution to optimize the production of each well. The generating includes using an offline model that includes a mixed-integer nonlinear program solver and includes using production curves based on a choke state and a given wellhead pressure. The method further includes calculating, using a network model and the intermediate solution of each well, a current online wellhead pressure for each well. The method further includes setting the intermediate solution as a final solution based on determining that a difference between the current online wellhead pressure of each well and a prior online wellhead pressure of each well is less than a tolerance amount. The method further includes adjusting, using the final solution of each well, at least one operating parameter of the wells.

Abstract: A method of optimizing production of wells using choke control includes generating, for each well, an intermediate solution to optimize the production of each well. The generating includes using an offline model that includes a mixed-integer nonlinear program solver and includes using production curves based on a choke state and a given wellhead pressure. The method further includes calculating, using a network model and the intermediate solution of each well, a current online wellhead pressure for each well. The method further includes setting the intermediate solution as a final solution based on determining that a difference between the current online wellhead pressure of each well and a prior online wellhead pressure of each well is less than a tolerance amount. The method further includes adjusting, using the final solution of each well, at least one operating parameter of the wells.

Abstract: A method and an apparatus for managing a subterranean formation including collecting information about a flow control valve in a wellbore traversing the formation, adjusting the valve in response to the information wherein the adjusting includes a Newton method, a pattern search method, or a proxy-optimization method. In some embodiments, adjusting comprises changing the effective cross sectional area of the valve. A method and an apparatus for managing a subterranean formation including collecting information about an inflow control valve in a wellbore traversing the reservoir and controlling the valve, wherein the control includes a direct-continuous approach or a pseudo-index approach.

Abstract: A method of optimizing production of wells using choke control includes generating, for each well, an intermediate solution to optimize the production of each well. The generating includes using an offline model that includes a mixed-integer nonlinear program solver and includes using production curves based on a choke state and a given wellhead pressure. The method further includes calculating, using a network model and the intermediate solution of each well, a current online wellhead pressure for each well. The method further includes setting the intermediate solution as a final solution based on determining that a difference between the current online wellhead pressure of each well and a prior online wellhead pressure of each well is less than a tolerance amount. The method further includes adjusting, using the final solution of each well, at least one operating parameter of the wells.

Abstract: A method can include selecting two control variables for a fluid production network; providing data acquired from the production network, the data associated with values for the two control variables; providing an interpolation model for interpolating the data over a domain defined by operational bounds for each of the two control variables; and solving a programming problem based at least in part on the interpolation model to provide values for at least one of the two control variables. Various other apparatuses, systems, methods, etc., are also disclosed.

Abstract: Methods and systems for performing well network production optimizations are described. For example, in one embodiment, a method of allocating an applied resource throughout a well network includes receiving topological data into an analytical model of a well network having one or more wells. The topological data includes a plurality of performance curves that relate well performance to one or more levels of an applied resource. The method also includes determining an optimum allocation of the applied resource using the analytical model to maximize an operating parameter of the well network, including converting a portion the analytical model having one or more wells and a linear inequality relationship to a modified portion having a single variable and a linear equality constraint.

Abstract: A method for optimizing expensive functions with expensive nonlinear constraints. The method includes selecting sample data for evaluating an expensive function of a simulation, generating a function proxy model for the expensive function and a constraint proxy model for an expensive nonlinear constraint of the expensive function using an approximation scheme, calculating a first solution point for the simulation using the proxy models, and evaluating the expensive function at the first solution point using the sample data. When the expensive function and the proxy models do not converge at the first solution point, the method further includes adding the first solution point to the sample data for updating the proxy models. The method further includes repeating the calculation and evaluation of solution points until the expensive function and the proxy models converge and, following convergence, identifying an optimal solution of the function proxy model and the constraint proxy model.

Abstract: A system performs production optimization for oilfields using a mixed-integer nonlinear programming (MINLP) model. The system uses an offline-online approach to model a network of interdependent wells in an online network simulator while modeling multiple interdependent variables that control performance as an offline MINLP problem. The offline model is based on production profiles established by assuming decoupled wells in the actual network of wells. In one example, an amount of lift-gas to inject and settings for subsurface chokes are optimized. An offline solver optimizes variables through the MINLP model. Offline results are used to prime the online network simulator. Iteration between the offline and online models results in a convergence, at which point values for the interdependent variables are communicated to the real-world oilfield to optimize hydrocarbon production.

Abstract: A method of optimizing production of wells using choke control includes generating, for each well, an intermediate solution to optimize the production of each well. The generating includes using an offline model that includes a mixed-integer nonlinear program solver and includes using production curves based on a choke state and a given wellhead pressure. The method further includes calculating, using a network model and the intermediate solution of each well, a current online wellhead pressure for each well. The method further includes setting the intermediate solution as a final solution based on determining that a difference between the current online wellhead pressure of each well and a prior online wellhead pressure of each well is less than a tolerance amount. The method further includes adjusting, using the final solution of each well, at least one operating parameter of the wells.

Abstract: A method is disclosed for optimal lift resource allocation, which includes optimally allocating lift resource under a total lift resource constraint or a total production constraint, the allocating step including distributing lift resource among all lifted wells in a network so as to maximize a liquid/oil rate at a sink.

Abstract: A method for optimizing expensive functions with expensive nonlinear constraints. The method includes selecting sample data for evaluating an expensive function of a simulation, generating a function proxy model for the expensive function and a constraint proxy model for an expensive nonlinear constraint of the expensive function using an approximation scheme, calculating a first solution point for the simulation using the proxy models, and evaluating the expensive function at the first solution point using the sample data. When the expensive function and the proxy models do not converge at the first solution point, the method further includes adding the first solution point to the sample data for updating the proxy models. The method further includes repeating the calculation and evaluation of solution points until the expensive function and the proxy models converge and, following convergence, identifying an optimal solution of the function proxy model and the constraint proxy model.

Abstract: A method is disclosed for optimal lift gas allocation, comprising: optimally allocating lift gas under a total lift gas constraint or a total produced gas constraint, the allocating step including distributing lift gas among all gas lifted wells in a network so as to maximize a liquid or oil rate at a sink.

Abstract: A system performs production optimization for oilfields using a mixed-integer nonlinear programming (MINLP) model. The system uses an offline-online approach to model a network of interdependent wells in an online network simulator while modeling multiple interdependent variables that control performance as an offline MINLP problem. The offline model is based on production profiles established by assuming decoupled wells in the actual network of wells. In one example, an amount of lift-gas to inject and settings for subsurface chokes are optimized. An offline solver optimizes variables through the MINLP model. Offline results are used to prime the online network simulator. Iteration between the offline and online models results in a convergence, at which point values for the interdependent variables are communicated to the real-world oilfield to optimize hydrocarbon production. Priming the online model with results from the offline model drastically reduces computational load over conventional techniques.

Abstract: One aspect of the invention relates to a method (10) for characterizing a well (700) using distributed temperature sensor (DTS) data to optimise a well model (12). The method comprises providing a well model of flow and thermal properties (12a, 12b) of the well (700), where the well model (12) has a plurality of adjustable physical parameters, providing a data set made up of a plurality of DTS temperature profiles of the well (700) taken at different times during operation of the well (700), and running the well model (12) with different combinations of the plurality of adjustable physical parameters to match to the plurality of DTS temperature profiles. The DTS temperature profiles may also be pre-processed to make them consistent with one another.

Abstract: Methods and systems for performing well network production optimizations are described. For example, in one embodiment, a method of allocating an applied resource throughout a well network includes receiving topological data into an analytical model of a well network having one or more wells. The topological data includes a plurality of performance curves that relate well performance to one or more levels of an applied resource. The method also includes determining an optimum allocation of the applied resource using the analytical model to maximize an operating parameter of the well network, including converting a portion the analytical model having one or more wells and a linear inequality relationship to a modified portion having a single variable and a linear equality constraint.

Abstract: A method is disclosed for optimal lift gas allocation, comprising: optimally allocating lift gas under a total lift gas constraint or a total produced gas constraint, the allocating step including distributing lift gas among all gas lifted wells in a network so as to maximize a liquid or oil rate at a sink.