Fracturing Tool Anchor Prevents Coiled Tubing Buckling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Coiled tubing used in horizontal wells is prone to buckling due to compressive forces when the bottom sealing elements of selective frac packers fail, especially in larger casing sizes where hydraulic forces exceed 200,000 psi, as it cannot effectively transmit upward forces away from the tubing.
Innovation Solution
A fracturing tool anchor with radially extending engagement members, such as pistons or slips, that engage the wellbore or casing wall to redirect compressive forces, preventing buckling by transmitting them to the earth rather than the coiled tubing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If coiled tubing is used in horizontal wells, then flexibility and speed of deployment are improved, but the tubing is prone to buckling under compressive forces when seal failure occurs
Solution Approach 1:
The anchor device acts as an intermediary between the coiled tubing and the wellbore wall. It transfers compressive forces from the tubing to the wellbore through engagement members (pistons or slips) that radially engage the casing or wellbore wall, preventing direct transmission of buckling forces to the tubing
Solution Approach 2:
The harmful compressive force is extracted from the coiled tubing system by introducing the anchor device. The anchor intercepts the upward force generated by seal failure and redirects it to the wellbore wall, removing the buckling risk from the tubing
2Reliability
If the bottom sealing elements fail, then pressure containment is maintained, but a net upward force is generated that causes coiled tubing buckling
Solution Approach 1:
The upward force generated by seal failure, which is harmful to the coiled tubing, is converted into a useful function by the anchor device. The engagement members are designed to be set by this very upward force, transforming the harmful hydraulic pressure into the mechanism that secures the anchor against the wellbore wall
3Force
If engagement members extend radially outwards to engage the casing wall, then force transmission to the earth is improved, but device complexity increases
Solution Approach 1:
The engagement members transition from a retracted state during deployment to an extended engaged state when force is applied. Pistons extend radially outward when hydraulic pressure is applied, while slips are forced outward by upward movement, allowing the device to adapt its configuration based on operational conditions
Solution Approach 2:
The anchor device is segmented into multiple independent engagement members distributed around the housing circumference. This segmentation allows the force transmission function to be distributed across multiple contact points with the wellbore wall, improving reliability while keeping each individual engagement member relatively simple
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 anchor effectively prevents buckling of coiled tubing by securely engaging the wellbore or casing wall, ensuring that upward forces are transmitted to the earth, thereby reducing the load on the tubing and maintaining its structural integrity.
Implementation Method 1
the hydraulic forces can easily exceed 200,000 psi
Implementation Method 2
engage the casing or wellbore wall
Data Source
AI summary
The present invention is directed to a fracturing tool anchor adapted for use with a work string in a wellbore. In one embodiment, the anchor has a housing with a central passage and an uphole and downhole end. The housing has a plurality of ports positioned circumferentially around the housing and along the length of the housing. The ports each contain an engagement member, such as a piston, and a return spring. The engagement member is adapted to extend radially outward when the anchor is pressure activated, to engage the wall of the casing or wellbore. The present application is also directed to a fracturing tool anchor that does not need to be pressure activated and utilizes slips as the engagement members.