Downhole Casing Cutting Assembly with Multiple Anchors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for well abandonment and casing removal require multiple trips into the well, leading to significant time and cost inefficiencies due to the need for repositioning anchor mechanisms to check and recover casing sections, especially when debris obstructs the cutting process.
Innovation Solution
A method and assembly that utilize multiple anchor mechanisms spaced along a work string to perform casing cutting and removal in a single trip, allowing for efficient testing and retrieval of cut sections without requiring repeated repositioning of the anchor mechanisms, using a combination of cutting and anchor mechanisms to grip and pull the casing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single anchor mechanism is used in combined cutting and pulling tools, then the tool structure is simplified, but multiple trips are required to reposition the anchor for checking and recovering casing sections
Solution Approach 1:
The single anchor mechanism is segmented into multiple anchor mechanisms (first anchor, second anchor, and third anchor) spaced at different positions along the work string. This allows different sections of casing to be anchored and recovered simultaneously during a single trip, eliminating the need to reposition anchors multiple times and significantly improving productivity while maintaining manageable tool structure through modular segmentation.
2Reliability
If the anchor is repositioned to check that the cut section of casing is free, then casing recovery can be verified, but significant time is lost in breaking-out and making-up the work string
Solution Approach 1:
The multiple anchors are pre-positioned along the work string at predetermined intervals before entering the wellbore. When casing is cut, the appropriate anchor is already in position to immediately engage and verify whether the cut section is free, eliminating the time-consuming process of repositioning anchors during the trip. The verification action is performed preliminarily as part of the continuous operation.
3Ease of operation
If multiple trips are made into the well, then casing can be recovered section by section, but substantial time and costs are incurred in making-up and breaking-out the work string
Solution Approach 1:
Multiple anchor mechanisms are merged into a single work string assembly, allowing the combined function of multiple separate operations (cutting, anchoring, verifying, and recovering different casing sections) to be performed in one integrated trip. This merging eliminates the need for multiple separate trips and the associated making-up and breaking-out operations, dramatically reducing total operation time while maintaining ease of operation through a unified tool design.
Data Source
AI summary
A downhole casing cutting and removal assembly (10) and method of use thereof, the assembly comprising a work string (23) with a cutting mechanism (18) and plurality of resettable anchor mechanisms (20B-20D). The arrangement allows a test pull to be made following the cut by an anchor mechanism closer to the upper end of the cut casing section than an anchor mechanism (20B-20D) located close to the cutting mechanism. Time is thus saved by not having to raise and lower a single anchor mechanism (20B-20D) between the cutting position and the upper end of the cut casing section to undertake a test pull.