Density-Based Inflow Control Valve for Water and Gas Discrimination
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Solution Overview
Problem
Current Autonomous Inflow Control Devices (AICDs) in petroleum wells struggle to accurately distinguish between desired and undesired fluids based on viscosity differences, especially when dealing with fluids like water and gas, which have similar viscosities, and fail to effectively block undesired fluids at high volume fractions due to insensitive effective viscosity changes.
Innovation Solution
A valve with a piston arrangement and separate flow paths, utilizing inflow control elements of different densities to respond to fluid density changes, ensuring the valve closes when undesired fluids exceed a predetermined level, independent of viscosity, velocity, and Reynolds number, with a pressure differential mechanism to move the piston and control fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If AICDs distinguish between unwanted fluids and wanted fluids based on viscosity differences, then fluid discrimination is achieved, but the system fails when fluids have similar viscosities (e.g., water and gas) or when effective viscosity changes are insensitive at high volume fractions
Solution Approach 1:
The patent changes the discrimination parameter from viscosity to density. The inflow control element uses density differences between fluids (oil, water, gas) to activate the valve, which is more reliable at high volume fractions where effective viscosity changes are insensitive. The density-based mechanism remains effective regardless of fluid mixing ratios.
2Adaptability or versatility
If AICDs rely on Reynolds number differences to control opening and closing, then flow characteristic discrimination is achieved, but the system becomes challenging in heterogeneous reservoirs with large variations in permeabilities and local inflow rates
Solution Approach 1:
The patent extracts the density measurement function from the complex Reynolds number-based flow characteristic analysis. By using a simple density-based inflow control element, the system removes sensitivity to velocity variations and Reynolds number changes, providing consistent performance across heterogeneous reservoirs with varying permeabilities and inflow rates.
3Measurement precision
If the effective viscosity of a two-phase mixture is used for control, then viscosity-based discrimination works at low volume fractions, but the control becomes insensitive when the unwanted fluid volume fraction approaches high values (close to 100%)
Solution Approach 1:
The patent changes the control parameter from effective viscosity to density. Density provides consistent discrimination capability across the entire range of volume fractions, including high values close to 100%, where effective viscosity becomes insensitive. The density-based inflow control element responds reliably regardless of the proportion of unwanted fluid in the mixture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The valve reliably blocks or restricts both water and gas inflows when their volume fraction exceeds a set limit, maintaining effective operation across various flow rates and fluid compositions, ensuring efficient oil production by minimizing unwanted fluid ingress.
Implementation Method 1
an inflow control element exposed to the fluid flow upstream of the flow barrier and having a density between a density of the desired fluid and a density of an undesired fluid, and being movable within a path between a first position and a second position in response to a density of fluid
Implementation Method 2
a piston arrangement movable within the valve between an inactive position allowing fluid flow through the primary flow channel and an active position preventing fluid flow through the primary flow channel
Implementation Method 3
The fluid discriminator section comprises a plurality of free floating balls, each ball operable to autonomously restrict a hole and thereby at least a portion of an undesired fluid type
Data Source
AI summary
A valve is for closing fluid communication between a horizontal or deviated well and a production string when a content of a first or a second undesired fluid in the fluid flow exceeds a predetermined level. The valve has a primary flow channel, and a piston arrangement movable within the valve between an inactive position allowing fluid flow through the primary channel and an active position preventing fluid flow through the primary channel. The piston arrangement further has a secondary flow channel and a bypass flow channel and inflow control elements exposed to the fluid flow upstream of the flow barrier and having different density and movable within independent paths in response to a density of fluid.