Downhole Differential Pressure Mover for Continuous Sampling
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Solution Overview
Problem
Downhole tools face limitations in generating sustained motion due to power supply constraints and operational challenges, particularly in small diameter tools and high-temperature environments, with existing systems often restricted to single actuation and limited by the need for air or formation pressure for piston activation.
Innovation Solution
A downhole tool apparatus with a moveable member and hydraulic circuitry that alternately exposes a first chamber to high and low pressures, using a piston with surfaces defining the chambers to create reciprocating motion, allowing for efficient fluid pumping and sampling by alternating fluid communication between the chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If electrical motors or hydraulic pumps are used to drive downhole tools, then mechanical motion can be achieved, but power supply limitations and device complexity increase
Solution Approach 1:
The patent employs hydraulic principles by using formation fluid pressure differentials to directly drive piston movement. The system utilizes high-pressure and low-pressure chambers connected to the formation, eliminating the need for external electrical power sources or complex hydraulic pump systems while achieving sustained mechanical motion through natural formation pressure variations.
2Ease of operation
If air chambers are used for single actuation, then piston activation is achieved, but sustained motion and continuous sampling are limited
Solution Approach 1:
The system implements periodic action by alternatingly exposing the piston to high-pressure and low-pressure formation fluid chambers in a cyclic manner. This periodic pressure differential application enables sustained reciprocating piston motion, allowing continuous fluid sampling and pumping operations rather than single actuation events.
Solution Approach 2:
The invention achieves continuous useful action by maintaining constant connection to formation fluid pressure sources through multiple chambers. The piston continuously alternates between high-pressure and low-pressure chambers, ensuring uninterrupted reciprocating motion and continuous sampling capability without requiring re-pressurization or resetting between cycles.
3Volume of moving object
If small diameter tools are used, then wellbore compatibility is improved, but power supply and operational capabilities are reduced
Solution Approach 1:
The system employs self-service by utilizing the formation fluid pressure itself as the power source, eliminating the need for external power supply systems. The formation pressure differential directly drives the piston mechanism, allowing small diameter tools to achieve adequate power for sampling operations without requiring large power supply components that would increase tool diameter.
4Duration of action of moving object
If formation pressure is continuously required for piston activation, then sustained motion is achieved, but operational flexibility and efficiency decrease
Solution Approach 1:
The system segments the formation pressure source into separate high-pressure and low-pressure chambers. This segmentation allows the piston to alternately access different pressure zones, achieving sustained reciprocating motion while improving operational efficiency by eliminating the need for continuous high-pressure formation fluid exposure throughout the entire sampling cycle.
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
Enables prolonged operation by effectively transferring fluid between high and low-pressure chambers, facilitating continuous fluid sampling and pumping without the need for constant high formation pressure, thus overcoming power supply and operational limitations.
Implementation Method 1
a first surface, defining a moveable boundary of a first chamber, and a second surface, defining a moveable boundary of a second chamber... exposing the first chamber to an alternating one of a first pressure and a second pressure that is substantially less than the first pressure
Data Source
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AI summary
A downhole tool for conveyance within a wellbore extending into a subterranean formation. The downhole tool comprises a moveable member comprising a first surface defining a moveable boundary of a first chamber, and a second surface defining a moveable boundary of a second chamber. The downhole tool further comprises hydraulic circuitry selectively operable to establish reciprocating motion of the moveable member by exposing the first chamber to an alternating one of a first pressure and a second pressure that is substantially less than the first pressure.