Exothermic Cast-In-Place Well Plugging to Prevent Channeling
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Solution Overview
Problem
Conventional plug and abandonment (P&A) operations face challenges such as contamination from drilling fluids, channeling issues with cement plugs, and the need for large blowout preventers, which increase costs and complexity.
Innovation Solution
A method involving a downhole tool to remove casing sections, deploying a blocking device, and using an exothermic fluid to liquefy and solidify a plugging material, forming a cast-in-place plug that expands to create a secure seal, eliminating the need for cement and reducing the requirement for large blowout preventers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cement is used to form plugs in conventional P&A operations, then the well can be sealed, but channeling occurs due to contamination from drilling fluids
Solution Approach 1:
The invention extracts and removes drilling fluid from the annulus before placing the plug, using a displacement fluid to push the drilling fluid out of the way. This eliminates the contamination issue that causes channeling in conventional cement plugs, allowing the plug material to set uniformly without channels forming through it.
Solution Approach 2:
The invention introduces a displacement fluid as an intermediary substance between the drilling fluid and the plug material. This displacement fluid serves as a mediator that separates the drilling fluid from the plug placement zone, preventing direct contact and contamination that would otherwise cause channeling.
2Reliability
If large blowout preventers are used in conventional P&A operations, then well control is ensured, but operational costs and complexity increase
Solution Approach 1:
The invention replaces the mechanical blowout preventer system with a chemically-activated plug placement system. Instead of using large mechanical devices to control the well, the method uses exothermic materials that generate heat to melt and inject plug material, substituting a complex mechanical well control system with a simpler chemical process.
Solution Approach 2:
The invention changes the state parameters of the plug material by using exothermic heat generation to melt solid plug material into a liquid state for injection, then allowing it to solidify in place. This parameter change (solid-liquid-solid) enables plug placement without requiring large mechanical blowout preventers, reducing device complexity while maintaining well control.
3Ease of manufacture
If conventional cementing procedures are used, then plugs can be set across zones, but poor mud removal creates channels through the plug
Solution Approach 1:
The invention performs preliminary action by displacing drilling fluid from the annulus before plug placement. A displacement fluid is pumped downhole to push the drilling fluid out of the target zone in advance, ensuring the area is clean and ready for uniform plug material placement without subsequent channeling issues.
Solution Approach 2:
The displacement fluid acts as an intermediary that temporarily occupies the space between the drilling fluid and the plug material. This intermediary substance ensures complete separation, allowing the plug material to set uniformly without channels, thereby improving manufacturing precision of the plug.
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
This approach ensures a reliable, cost-effective, and efficient plug formation that avoids channeling and reduces operational costs by eliminating the need for large blowout preventers, allowing for secure well abandonment with improved sealing efficiency.
Implementation Method 1
deploying an exothermic fluid downhole, wherein activation of the exothermic material liquefies the plugging material
Implementation Method 2
allowing the plugging material and the exothermic fluid to solidify form a cast-in-place plug
Data Source
AI summary
A method of plugging a hydrocarbon well includes deploying a downhole tool to remove at least a portion of a casing at a section of well to be plugged. Then a plugging material is put downhole onto a blocking device to fill an area to be plugged. An exothermic fluid is added, wherein activation of the exothermic material liquefies the plugging material. Allowing the plugging material and the exothermic fluid to solidify form a cast-in-place plug that fills the section of well to be plugged.