Downhole Casing Pulling Tool Hydraulic Anchor
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Solution Overview
Problem
Traditional methods for removing stuck casing in wells are time-consuming, labor-intensive, and often damage the casing or other well components, especially when using pilot milling or jarring techniques, which are ineffective for stuck casing in mud.
Innovation Solution
A downhole casing pulling tool with an anchor and puller system, featuring a mandrel, carrier, and inserts that engage the internal surface of the tubular, allowing for controlled anchoring and retrieval of stuck casing without damaging it, using hydraulic pressure to set and unset the anchor and puller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pilot milling is used to remove stuck casing, then the casing can be retrieved, but the process becomes very time-consuming and labor-intensive
Solution Approach 1:
The patent replaces the mechanical milling process with a hydraulic pulling system. A downhole pulling tool uses hydraulic pressure to expand anchors that grip the casing internally, allowing the stuck casing to be pulled out directly without milling. This substitution of hydraulic expansion and mechanical gripping for rotational milling dramatically reduces retrieval time and labor requirements.
Solution Approach 2:
The invention extracts the casing retrieval function from the milling process entirely. Instead of removing material to free the casing, the system directly grips and extracts the stuck casing using the pulling tool's anchor mechanism, eliminating the time-consuming milling step while achieving reliable retrieval.
2Force
If jarring action is used to pull casing free, then retrieval force can be applied, but the technique is ineffective for stuck casing in mud
Solution Approach 1:
The patent employs hydraulic pressure to actuate the pulling tool's components. Hydraulic fluid is pumped downhole to expand the anchors and engage them with the casing's internal surface. This hydraulic mechanism provides controlled, sustained pulling force that is effective for retrieving stuck casing in mud, overcoming the limitations of mechanical jarring action.
Solution Approach 2:
The patent introduces hydraulic fluid as an intermediary between the surface equipment and the stuck casing. The hydraulic system transmits force through the fluid medium to the downhole pulling tool, which then transfers this force to the casing via the anchor mechanism, providing reliable retrieval capability in muddy conditions where direct mechanical jarring fails.
3Reliability
If traditional pulling methods are used, then casing can be retrieved, but the casing or other well components may be damaged
Solution Approach 1:
The patent uses a flexible gripping mechanism where the anchor elements can conform to the internal surface of the casing. The anchor segments are designed to flex and adapt to the casing's geometry, distributing the pulling force evenly across the engagement surface. This prevents stress concentration and potential damage to the casing, while still providing sufficient grip for retrieval.
Solution Approach 2:
The pulling tool incorporates dynamic elements that allow the anchor mechanism to adjust to the casing's position and orientation. The movable anchor segments can shift and reposition themselves to maintain optimal engagement, preventing sudden force spikes that could damage the casing or other well components during the retrieval process.
4Reliability
If milling is used to remove stuck components, then retrieval is achieved, but equipment wear increases and metallic waste is generated
Solution Approach 1:
The patent replaces the material-removing milling process with a mechanical gripping and pulling system. Instead of cutting away metal to free the stuck component, the hydraulic anchor mechanism grips the component intact and pulls it out. This eliminates metallic waste generation and reduces wear on milling equipment while achieving reliable retrieval.
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 effective retrieval of stuck casing without the need for milling, reducing rig time and equipment wear, and eliminating metallic waste, while allowing for larger pulling forces and torque transmission through the tool's design.
Implementation Method 1
slips which utilize slip members and cones to frictionally affix the new string of liner in the wellbore
Implementation Method 2
using hydraulic pressure to set and unset the anchor and puller
Data Source
AI summary
A method and apparatus for removal of tools, tubulars, casing, or other components that become stuck in a well. An anchor includes a mandrel, a carrier disposed on the mandrel and movable relative to the mandrel between an extended position and a retracted position, and an insert configured to engage an internal surface of a tubular, the insert movably disposed in the carrier as the carrier moves between the extended position and the retracted position. A method for anchoring a tool in a wellbore includes deploying the tool into the wellbore through a tubular to a first position, the tool comprising an anchor having a carrier and an insert disposed in the carrier, extending the carrier towards the tubular, and moving the insert relative to the carrier while engaging the inserts with the tubular, thereby anchoring the tool in the wellbore.