Downhole Casing Pulling Tool for Controlled Stuck-Casing Retrieval
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for removing stuck downhole casing are inefficient and prone to mechanical and hydraulic issues, particularly in high-sea conditions, and lack effective tools for cutting and pulling operations.
Innovation Solution
A downhole casing pulling tool with a tubular housing, packer assembly, slip assembly, and piston assembly that uses fluid pressure modification to actuate the packer and slip assemblies, allowing for controlled cutting and retrieval of casing through a rotary cutter or abrasive device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional mechanical tools are used for removing stuck casing, then the tool structure is simple, but the tool fails during high-sea conditions and requires complex hydraulic operations with inconsistent forces
Solution Approach 1:
The patent replaces traditional hydraulic actuation systems with a mechanically actuated piston system. The piston is directly driven by rotational motion from the work string, converting rotational mechanical energy into linear reciprocating motion. This mechanical direct-drive system eliminates complex hydraulic valves, pumps, and fluid delivery mechanisms, providing reliable operation in high-sea conditions while reducing overall system complexity.
Solution Approach 2:
The piston assembly is designed to automatically actuate the cutter and packer components through its reciprocating motion. As the piston moves back and forth, it directly engages and actuates the cutting elements and packer elements without requiring external hydraulic control systems. The system uses the mechanical energy from the work string rotation to self-actuate all necessary components for casing removal.
2Productivity
If conventional cutting tools are used, then the tool design is simple, but cutting efficiency is low and retrieval time is extended
Solution Approach 1:
The cutting system is divided into multiple independent cutter elements that can be individually actuated by the piston assembly. The cutters are segmented into separate units that can engage the casing at different positions and times, allowing for more efficient cutting through the thick casing wall. This segmentation enables parallel cutting actions and reduces total cutting time compared to a single cutter element.
Solution Approach 2:
The piston assembly creates periodic reciprocating motion that repeatedly engages and disengages the cutter elements with the casing. This periodic action allows the cutters to chip away at the casing in successive strokes, progressively working through the material. The rhythmic engagement and disengagement of cutters during each piston cycle enables efficient material removal while reducing the continuous load on individual cutting elements.
3Ease of operation
If hydraulic actuation is used for packer and slip assemblies, then operation is automated, but different components operate at different hydraulic forces causing inconsistency
Solution Approach 1:
The single piston assembly serves multiple functions by sequentially actuating different components during its reciprocating cycle. The same piston that drives the cutter elements also actuates the packer elements and slip elements through mechanical linkages. This universal actuation mechanism ensures all components receive the same mechanical force and operate in a coordinated, consistent manner, eliminating the variability inherent in multi-system hydraulic actuation.
Solution Approach 2:
The patent merges the actuation of multiple components (cutter, packer, and slip assemblies) into a single mechanically integrated system. Instead of separate hydraulic circuits controlling each component, all actuation forces are derived from the same piston mechanism. This consolidation ensures uniform force application and synchronized operation of all components, improving reliability and operational consistency.
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 efficient and controlled cutting and pulling of downhole casing, even in challenging conditions, by using fluid pressure to actuate the tool's components, ensuring reliable disengagement and retrieval of stuck casing.
Implementation Method 1
a piston assembly disposed in the bore of the tubular housing. The piston assembly is configured to operate an actuator, wherein the actuator is configured to operate at least one of the packer assembly and the slip assembly and modify a fluid pressure in the bore of the tubular housing
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A method and apparatus for cutting and pulling a casing string from a well. A downhole casing pulling tool includes a tubular housing having a bore therethrough, a packer assembly configured to isolate an annulus between a casing and the tool, a slip assembly configured to engage the casing, and a piston assembly disposed in the bore of the tubular housing. The piston assembly is configured to operate an actuator, wherein the actuator is configured to operate at least one of the packer assembly and the slip assembly and modify a fluid pressure in the bore of the tubular housing.