Rotational Spear Packer Assembly for Single-Run Casing Retrieval
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Solution Overview
Problem
Existing well operations require multiple runs to cut and free stuck tubulars, increasing rig time and reducing operational efficiency, and there is a need for tools and methods that can address various well challenges with fewer trips.
Innovation Solution
A spear and packer tool that allows for simultaneous casing engagement and pressure sealing, enabling rotation of a workstring with a rotational-set retrievable packer, and includes a mechanism for differential pressure anchoring and mechanical setting of slips to grip and seal the casing, allowing for combined operations like cutting and pressure testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple runs are used to cut and free stuck tubulars, then operational reliability is improved, but rig time and productivity deteriorate
Solution Approach 1:
The patent combines multiple downhole operations (casing cutting, pressure sealing, and tubular retrieval) into a single integrated tool assembly that can perform all functions during one run. The spear tool engages the casing, the packer seals the annulus, and the cutting mechanism severes the casing, all while maintaining pressure control, eliminating the need for multiple separate trips.
Solution Approach 2:
The downhole tool assembly is designed with multi-functionality, serving as both a spear tool for casing engagement, a packer for pressure sealing, and a cutting tool for severing the casing. This universal tool can handle various well challenges (cutting, sealing, retrieving) in a single deployment, improving productivity without sacrificing operational reliability.
2Adaptability or versatility
If multiple runs are used to address well challenges, then operational completeness is improved, but device complexity and time consumption worsen
Solution Approach 1:
Rather than deploying multiple specialized tools in separate runs, the patent merges cutting mechanisms, packing elements, spear anchoring systems, and pressure control valves into a single integrated toolstring. This consolidated design maintains operational completeness by providing all necessary functions in one assembly, reducing the need for multiple trips while managing complexity through integration.
Solution Approach 2:
The toolstring is designed as a universal assembly that can adapt to different well conditions and perform multiple operations (cutting various casing sizes, sealing annuli, retrieving tubulars) without requiring更换 tools or multiple runs, thereby achieving operational completeness through a single versatile device.
3Reliability
If traditional spear tools are used without rotational capability, then anchoring reliability is improved, but operational versatility deteriorates
Solution Approach 1:
The spear anchor mechanism is designed to maintain reliable engagement with the casing while allowing the workstring and mandrel to rotate. The slips and anchor elements are configured to grip the casing firmly during rotation, enabling both reliable anchoring and rotational movement for operations like cutting and pressure testing without compromising anchor integrity.
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
Facilitates single-run operations for cutting and retrieving casing by providing a tool that can grip, seal, and rotate, reducing rig time and enhancing operational efficiency by combining multiple functions in a single trip.
Implementation Method 1
said spear anchor mechanism is arranged to be set by differential pressure
Implementation Method 2
said packer assembly is arranged to be set by applying left hand rotation to the mandrel while the slips segments are engaged with the casing
Data Source
AI summary
A spear and packer tool is arranged for being conveyed on a drill pipe string. The tool has a mandrel having a through bore, a spear anchor mechanism configured to grip a section of casing in a wellbore for removal therefrom, the spear anchor mechanism being arranged to be set by differential pressure, said spear anchor mechanism being rotational relative to the mandrel, and a packer assembly being a mechanical rotational-set retrievable packer configured to seal an annulus between the spear and packer tool and the casing. The packer assembly is arranged to be set by applying left hand rotation to the mandrel while the slips segments are engaging the casing, the packer assembly being arranged below the spear anchor mechanism. A downhole casing cutting and retrieval assembly including the spear and packer tool and a method for operating the tool and assembly are disclosed.