Wireline Logging Tool Zone Isolation
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Solution Overview
Problem
Existing methods for evaluating subterranean formations face challenges in controlling fluid introduction and resistivity measurements due to difficulties in creating uniform salinity changes and mitigating electrical pathways that distort formation resistivity readings.
Innovation Solution
The creation of hydraulically distinct zones using hydraulic isolators and sensors allows for controlled fluid introduction of different conductivity fluids, enabling precise resistivity measurements by isolating zones and positioning sensors on packers to mitigate electrical interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If hydraulic isolators are used to create hydraulically distinct zones, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The borehole is divided into multiple hydraulically distinct zones using packers (hydraulic isolators). Each zone can be independently flooded with fluids of different conductivities, allowing separate resistivity measurements in each zone. This segmentation enables precise control over fluid distribution and eliminates electrical pathway interference between zones, directly improving measurement precision.
2Measurement precision
If sensors are positioned on packers to mitigate electrical interference, then measurement precision is improved, but ease of operation deteriorates
Solution Approach 1:
The electrical sensors are integrated directly onto the packer structure itself, combining the isolation function and measurement function into a single component. This merging eliminates the need for separate sensor deployment operations and simplifies the overall system architecture while maintaining measurement precision by ensuring sensors are positioned exactly where electrical interference mitigation is most effective.
3Measurement precision
If multiple fluids of different conductivity are introduced to create salinity fronts, then measurement precision is improved, but loss of substance increases
Solution Approach 1:
By dividing the borehole into hydraulically distinct zones using packers, the system can introduce different conductivity fluids into specific zones independently. This segmentation allows for more efficient fluid utilization compared to flooding the entire borehole, as fluids are targeted precisely where needed to create salinity fronts for measurement, reducing overall fluid consumption while maintaining measurement precision.
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 approach enhances the accuracy of multiphase flow characterization by creating timely and uniform salinity changes, reducing electrical pathway interference, and improving the sensitivity of measurements for relative permeability and capillary pressure analysis.
Implementation Method 1
hydraulic isolators which create a plurality of hydraulically distinct zones when actuated
Implementation Method 2
a plurality of sensors for obtaining measurements of formation resistivity adjacent to ones of the hydraulically distinct zones
Implementation Method 3
introducing fluids of different conductivity to at least one of the hydraulically distinct zones
Data Source
AI summary
A wireline logging tool and method for fluid monitoring and flow characterization in individual zones of controlled salinity is disclosed. The tool and method advantageously facilitate zone-specific testing. Sets of packers are used to create hydraulically distinct zones proximate to the tool. Coiled tubing and isolation valves are used to selectively introduce and remove an electrically conductive fluid such as brine to and from a selected zone. Individual sensors are disposed near each zone to make zone-specific measurements while fluid properties are changed, e.g., while salinity is changed to cause salinity fronts in the formation.