Adjoint Gradient Optimization for Multi-Segmented Well Valve Settings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current control strategies for controllable down-hole devices in reservoirs are often reactive and heuristic, failing to optimize valve settings effectively for maximizing hydrocarbon recovery, as they do not consider the future impact on the entire reservoir, leading to potential breakthroughs and inefficient production.
Innovation Solution
The Adjoint Method calculates gradients of an objective function with respect to valve settings, taking into account pressure drop and fluid flow, to optimize control of wells by determining sensitivities and using them to maximize the objective function through a proactive deterministic constrained optimization method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If reactive control strategies are used for valve settings, then operational simplicity is maintained, but hydrocarbon recovery is not maximized due to lack of consideration for future reservoir impact
Solution Approach 1:
The adjoint method calculates gradients of the objective function with respect to valve settings at each time step, enabling proactive optimization decisions that consider future reservoir impact before breakthrough occurs. This preliminary action allows the system to delay breakthrough and maximize hydrocarbon recovery by making informed control decisions ahead of time rather than reacting after problems arise.
2Productivity
If proactive control strategies are implemented to delay breakthrough, then hydrocarbon recovery is maximized, but computational complexity increases significantly
Solution Approach 1:
The adjoint method provides efficient gradient calculation that feeds back into the optimization algorithm, enabling the system to determine sensitivities of the reservoir to changes in valve settings. This feedback mechanism allows the optimization to converge efficiently by using the calculated gradients to guide subsequent valve setting adjustments, maximizing hydrocarbon recovery without excessive computational time loss.
3Productivity
If adjoint gradient technology is used to optimize valve settings, then optimization efficiency is improved, but modeling complexity of pressure drop and fluid flow increases
Solution Approach 1:
The adjoint system acts as an intermediary that efficiently computes gradients of the objective function with respect to valve settings by incorporating the complex pressure drop and fluid flow models. Rather than directly solving the complex optimization problem with full modeling complexity, the adjoint method provides a computational bridge that enables efficient optimization while accounting for the detailed physics of multi-segmented well models.
Data Source
AI summary
A new adjoint method for calculating and using adjoint gradients in a Reservoir Simulator comprises: calculating adjoint gradients of an objective function with respect to changes in valve settings taking into account the modeling of pressure drop and fluid flow along a wellbore, and using the adjoint gradients to calculate sensitivities of a reservoir to changes in parameterization of downhole devices and using of these sensitivities in optimal control of the wells to optimize some objective function subject to production constraints.