Magnetic Perturbation Flow Rate Estimation in Wellbores
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Solution Overview
Problem
Existing methods for estimating flowback or reservoir fluid production rate in wellbores are inaccurate due to limited access and complexity in measuring fluid velocity, especially when multiple inlets are involved, as they rely on indirect methods like temperature and pressure sensors or complex flow scanner tools that interfere with the flow.
Innovation Solution
A method using magnetic irregularity elements, such as ferromagnetic collars, distributed along the wellbore casing to generate perturbations, combined with sensor elements that record these perturbations as they are dragged by the fluid, allowing for precise estimation of fluid velocity and flow rate by calculating the travel time between known locations of the magnetic irregularity elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature and pressure sensors are installed in the casing to measure flow parameters, then measurement capability is provided, but measurement precision is poor due to indirect estimation methods
Solution Approach 1:
The patent replaces mechanical/thermal sensing methods (temperature and pressure sensors) with a magnetic field-based measurement system. Magnetic irregularity elements (such as ferromagnetic collars) are attached to the casing at known locations, and a magnetic sensor mounted on a flow scanner tool measures magnetic field perturbations as it moves with the fluid flow. This substitution enables direct velocity measurement through travel time calculation, significantly improving measurement precision while avoiding the indirect estimation limitations of thermal and pressure-based methods.
2Measurement precision
If flow scanner tools with helical turbines are used to measure flow velocity, then velocity measurement capability is provided, but device complexity increases and flow interference occurs
Solution Approach 1:
The patent extracts the measurement function from intrusive mechanical devices (helical turbines) and implements it through a passive magnetic field interaction system. The flow scanner tool contains no moving parts or flow-obstructing elements; instead, it uses magnetic sensors to detect perturbations caused by ferromagnetic collars attached to the casing. This extraction eliminates flow interference while maintaining measurement capability, as the magnetic field interaction does not physically obstruct or disturb the fluid flow.
Solution Approach 2:
The patent introduces magnetic field interaction as an intermediary mechanism between the measurement system and the fluid flow. Rather than directly measuring flow properties with intrusive sensors, the system uses magnetic irregularity elements as intermediaries that perturb the magnetic field in a predictable manner as the flow passes them. The sensor detects these perturbations to infer velocity, creating a non-intrusive measurement pathway that avoids direct contact with the flowing fluid.
3Reliability
If indirect methods using temperature and pressure correlations are used to estimate flow rate, then measurement capability is provided, but reliability is low especially with complex fluid compositions
Solution Approach 1:
The patent replaces complex numerical models and indirect thermal/pressure correlations with a direct mechanical measurement approach based on travel time. By mounting a sensor on a flow scanner tool that moves with the fluid and timing its passage between known magnetic irregularity elements, the system directly measures velocity without requiring assumptions about fluid composition, temperature, or pressure relationships. This substitution dramatically improves reliability for complex multi-phase flows where indirect methods fail.
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
This method provides a reliable and simple means to estimate flowback or reservoir fluid production rate from individual or multiple inlets, overcoming the limitations of previous technologies by accurately determining fluid velocity and flow rate without interfering with the flow, even in complex fluid compositions with multiple phases.
Implementation Method 1
These magnetic irregularity elements generate magnetic perturbations within the casing
Implementation Method 2
the sensor elements record in time the magnetic perturbations generated by the magnetic irregularity elements
Implementation Method 3
the flow drags them while the sensor elements record in time the magnetic perturbations
Data Source
AI summary
A method is described for estimating either flowback or the reservoir fluids production rate from either one individual inlet or the contribution from several inlets separated by intervals in a wellbore located in an oil and/or gas reservoir. The wellbore may include a casing with a plurality of magnetic irregularity elements, such as casing collars, to generate magnetic perturbations within the casing. In the method, one or more sensor elements are delivered in such a way that the flow drags them while the sensor elements record in time the magnetic perturbations generated by the magnetic irregularity elements. The known location of the magnetic irregularity elements and the reading of perturbations enables estimating the velocity of the sensor element(s) along the path direction of the casing, to determine the velocity of the fluid.