Abstract: A method for deriving VOI for a hydrocarbon-bearing reservoir fluid model based on DFA data (“true fluid model”) versus an “incorrect fluid model” includes calculating first, second and third objective functions that are based on NPV(s) of simulated production by a reservoir simulator with different configurations. For the first objective function, the simulator is configured with the incorrect fluid model and control variables that are optimized to derive a first group of control variable values. For the second objective function, the simulator is configured with the true fluid model and the first group of control variable values. For the third objective function, the simulator is configured with the true fluid model and control variables that are optimized to identify a second group of control variable values. The objective functions can be deterministic, or can include statistics that account for uncertainty. A visualization of such results with uncertainty is also described.

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: Methods and systems are provided for modeling an aspect of a hydrocarbon-containing reservoir by constructing a first factor graph having variables and factors that describe the aspect of the hydrocarbon-containing reservoir. The first factor graph is converted to a tree-structured graph that does not have any cycle or loops. The tree-structured graph is converted to a second factor graph that does not contain any cycles or loops, wherein the second factor graph has variables and factors that describe the aspect of the hydrocarbon-containing reservoir. A query on the second factor graph is carried out involving message passing operations that perform probabilistic inference on the second factor graph with regard to the aspect of the hydrocarbon-containing reservoir that is modeled by the second factor graph.

Abstract: Oilfield management includes obtaining a binary variable array describing configurable elements of an oilfield design, partitioning the binary variable array into subgroups, and applying a transformation function to each subgroup to obtain an integer variable for each subgroup. An optimization problem is solved on the binary variable array by treating the integer variable as a continuous variable to obtain a solution, and the transformation function of each subgroup is applied to the solution to obtain a design pattern. Based on the design pattern, the oilfield design is generated.

Abstract: Methods are disclosed for assigning a value to a geological asset or information relating thereto in the presence of private and public sources of uncertainties. The private and public uncertainties associated with a geological asset or information associated therewith are defined, and private uncertainties are assigned a subjective probability representing the best state of knowledge currently available. A multi-dimensional valuation-time lattice is constructed using the subjective probabilities for the private uncertainties and using risk-neutral probabilities for the public uncertainties. A backward recursion through the multi-dimensional lattice is performed in order to generate a present value for the asset given the present information available. During the backward recursion, a tally of delta hedging coefficients is generated and stored in order to provide an operational “map” or “decision pathway” should the project move forward.

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: Oilfield management includes obtaining a binary variable array describing configurable elements of an oilfield design, partitioning the binary variable array into subgroups, and applying a transformation function to each subgroup to obtain an integer variable for each subgroup. An optimization problem is solved on the binary variable array by treating the integer variable as a continuous variable to obtain a solution, and the transformation function of each subgroup is applied to the solution to obtain a design pattern. Based on the design pattern, the oilfield design is generated.

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: Methods and systems are provided for modeling an aspect of a hydrocarbon-containing reservoir by constructing a first factor graph having variables and factors that describe the aspect of the hydrocarbon-containing reservoir. The first factor graph is converted to a tree-structured graph that does not have any cycle or loops. The tree-structured graph is converted to a second factor graph that does not contain any cycles or loops, wherein the second factor graph has variables and factors that describe the aspect of the hydrocarbon-containing reservoir. A query on the second factor graph is carried out involving message passing operations that perform probabilistic inference on the second factor graph with regard to the aspect of the hydrocarbon-containing reservoir that is modeled by the second factor graph.

Abstract: A method for deriving VOI for a hydrocarbon-bearing reservoir fluid model based on DFA data (“true fluid model”) versus an “incorrect fluid model” includes calculating first, second and third objective functions that are based on NPV(s) of simulated production by a reservoir simulator with different configurations. For the first objective function, the simulator is configured with the incorrect fluid model and control variables that are optimized to derive a first group of control variable values. For the second objective function, the simulator is configured with the true fluid model and the first group of control variable values. For the third objective function, the simulator is configured with the true fluid model and control variables that are optimized to identify a second group of control variable values. The objective functions can be deterministic, or can include statistics that account for uncertainty. A visualization of such results with uncertainty is also described.

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 system for automatically optimizing a Field Development Plan (FDP) for an oil or gas field uses a fast analytic reservoir simulator to dynamically model oil or gas production from the entire reservoir over time in an accurate and rapid manner. An objective function defining a Figure of Merit (FoM) for candidate FDPs is maximized, using an optimization algorithm, to determine an optimized FDP in light of physical, engineering, operational, legal and engineering constraints. The objective function for the Figure of Merit, e.g., net present value (NPV) or total production for a given period of time, relies on a production forecast from the fast analytic reservoir simulator for the entire FDP.

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 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 determining a selection of well measurements and/or their respective control parameters is described based on a global target having predetermined sensitivities to a multitude of uncertainties associated with input variables to a model including the step of ranking measurements and control parameters in accordance with their capability to reduce the uncertainties of input variables identified as most sensitive input variables through simulations using the model or a reduced variant of the model.

Abstract: A statistical methodology is disclosed to provide time-to-event estimates for oilfield equipment. A method according to the present invention extracts unbiased information from equipment performance data and considers parameters interactions without recourse to data thinning. The analysis explicitly accounts for items of equipment that are still operational at the time of analysis. A method according to the present invention may also be utilized to apply survival analysis to any oilfield equipment components where time-to-event information has been recorded. The method of the present invention allows comparative reckoning between different components present in the system comprising several or many individual components and allows analysis of these components either individually or simultaneously, i.e., in the presence of other components.