Untethered Downhole Logging Using Buoyancy and Drag Control
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Solution Overview
Problem
Conventional tethered logging tools for measuring downhole properties in subterranean wells are bulky, require specialized equipment and crews, and often necessitate stopping well operations, which is costly and time-consuming.
Innovation Solution
An untethered, buoyancy-controlled and/or drag-controlled device that uses fluid forces to navigate along the wellbore, allowing for deployment and retrieval by a single technician without the need for specialized equipment, enabling continuous data collection without disrupting well operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tethered logging tools are used to measure downhole properties, then measurement capability is provided, but device complexity and operational cost increase due to required specialized equipment and crews
Solution Approach 1:
The patent removes the tether (cable, wireline, or coiled tubing) that connects the logging tool to the surface, extracting the constraint that causes complexity. The untethered device floats freely in the wellbore fluid, eliminating the need for specialized deployment equipment and crews while maintaining measurement capability through wireless or stored-data retrieval methods.
Solution Approach 2:
The logging device serves itself by using the wellbore fluid's buoyancy and drag forces for positioning and movement. The device autonomously navigates the wellbore without external mechanical assistance, reducing operational complexity. Data is stored locally and retrieved when the device is recovered, eliminating the need for continuous tethered communication.
2Reliability
If tethered logging tools are deployed, then downhole measurements can be obtained, but productivity decreases due to stopping well operations
Solution Approach 1:
The untethered logging device enables continuous well operations by being deployed without stopping production. The device floats into position alongside the flowing wellbore fluid and collects measurements during normal operation. Data is stored in the device's memory and retrieved after recovery, allowing the well to remain productive throughout the measurement process.
3Reliability
If conventional tethered tools are used, then measurements are obtained, but loss of time occurs due to deployment and retrieval operations
Solution Approach 1:
The patent replaces the mechanical tether-based deployment system with a fluid-dynamics-based system. The untethered device uses buoyancy and drag forces from the wellbore fluid to position and move the device, eliminating time-consuming mechanical deployment and retrieval operations. The device can be introduced into the wellbore more quickly and efficiently.
4Ease of operation
If untethered buoyancy-controlled device is used, then ease of operation improves with single technician deployment, but control precision may be affected by fluid dynamics
Solution Approach 1:
The device incorporates sensors and control systems that monitor its position and motion in real-time. Based on feedback from these sensors, the control system adjusts buoyancy (by changing device volume or mass) and drag (by adjusting device orientation or surface area) to maintain precise positioning despite fluid dynamics variations, ensuring measurement accuracy while maintaining ease of operation.
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 untethered device reduces logistical and operational delays, lowers costs, and allows for comprehensive measurement of physical, chemical, and structural properties along the wellbore without the need for cables or wired networks, facilitating more efficient and cost-effective well management.
Implementation Method 1
a controller to control a buoyancy of the untethered device for controlling a position of the untethered device in the subterranean well
Implementation Method 2
a controller to control at least one of a buoyancy and a drag of the untethered device to control a position of the untethered device in the subterranean well
Data Source
AI summary
Embodiments of the invention provide an untethered apparatus for measuring properties along a subterranean well. According to at least one embodiment, the untethered apparatus includes a housing, and one or more sensors configured to measure data along the subterranean well. The data includes one or more physical, chemical, geological or structural properties in the subterranean well. The untethered apparatus further includes a processor configured to control the one or more sensors measuring the data and to store the measured data, and a transmitter configured to transmit the measured data to a receiver arranged external to the subterranean well. Further, the untethered apparatus includes a controller configured to control the buoyancy or the drag of the untethered apparatus to control a position of the untethered apparatus in the subterranean well. The processor includes instructions defining measurement parameters for the one or more sensors of the untethered apparatus within the subterranean well.