Pressure Compensated Actuator for Downhole Tools
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current downhole actuator systems in the drilling and completion industry face challenges in overcoming tubing pressure, which requires high activation energy and results in increased costs and reduced longevity due to dynamic friction at seals.
Innovation Solution
A tubing pressure insensitive, pressure compensated actuator system is designed with a housing and a force transmitter having fluid chambers, sealed with bearings and compensation piston to isolate ends from tubing pressure, allowing the activator to generate force sufficient for tool activation without overcoming tubing pressure, thus reducing friction and wear on seals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the actuator is configured to overcome tubing pressure, then the tool can be actuated, but the activation energy required increases
Solution Approach 1:
The actuator system is segmented into separate functional components: a compensating piston that handles tubing pressure independently, and an activator that only needs to generate force for tool actuation. This segmentation allows the activator to operate without overcoming tubing pressure, reducing activation energy requirements while maintaining reliable actuation capability.
Solution Approach 2:
A compensating piston is introduced as an intermediary element between the tubing pressure environment and the activator. This compensating piston absorbs and compensates for tubing pressure effects, allowing the activator to operate in a pressure-compensated environment where it only needs to generate force for pure actuation motion, not for overcoming external pressure.
2Reliability
If the actuator operates against tubing pressure, then actuation can be achieved, but dynamic friction at seals increases causing reduced longevity
Solution Approach 1:
The system segments the force generation and force application functions. The compensating piston handles the high-force requirement of overcoming tubing pressure separately, while the activator only applies force for actuation. This reduces the total force that seals must withstand, minimizing dynamic friction and extending seal longevity.
Solution Approach 2:
The compensating piston acts as an intermediary that absorbs the harmful effect of tubing pressure on the seals. By placing the compensating piston between the tubing pressure source and the activator seals, it compensates for pressure differential effects, reducing seal friction and wear while maintaining actuation functionality.
3Reliability
If high activation energy is used to overcome tubing pressure, then tool actuation is achieved, but operational costs increase
Solution Approach 1:
The actuator system segments the energy requirements: the compensating piston handles the energy-intensive pressure compensation function, while the activator only requires minimal energy for actuation. This segmentation reduces overall activation energy requirements, leading to lower operational costs while maintaining reliable actuation through the compensating mechanism.
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 solution reduces the force requirements for actuation, enhances reliability, and extends the lifespan of downhole tools by minimizing the impact of tubing pressure on the actuator system, leading to lower operational costs and improved performance.
Implementation Method 1
a separate compensation piston disposed in the housing so as to expose one end of the compensation piston to tubing pressure and to expose the other end of the compensation piston to a fluid volume including the fluid chambers
Implementation Method 2
initiating an activator to urge the force transmitter in a direction commensurate with activating a downhole tool, the activator generating enough force to activate the downhole tool other than to overcome tubing pressure
Implementation Method 3
at least two seals sealingly positioned between the housing and the force transmitter, one of the seals disposed near one end of the force transmitter and another of the seals disposed near another end of the force transmitter
Data Source
AI summary
A tubing pressure insensitive, pressure compensated actuator system includes a housing having a bore therein. A force transmitter sealingly moveable within the bore. The force transmitter defining with the bore two fluid chambers. The two fluid chambers being in fluid communication with each other, one at each longitudinal end of the force transmitter. An activator in one or both of the two fluid chambers and operatively connected to the force transmitter. At least two seals sealingly positioned between the housing and the force transmitter. One of the seals disposed near one end of the force transmitter and another of the seals disposed near another end of the force transmitter. A separate compensation piston disposed in the housing so as to expose one end of the compensation piston to tubing pressure and to expose the other end of the compensation piston to a fluid volume including the fluid chambers. Also included is a method for reducing force requirements of an actuator.