Thermite Heater for Metal Plugging in Well Casings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for plugging and sealing subterranean wells, particularly using metal plugs, face inefficiencies due to limited capacity for lateral filling of perforations and the inability to reuse heater tools effectively, leading to increased operation costs and time.
Innovation Solution
A plugging device featuring a cylindrical sleeve with a thermite heater and ignition mechanism, allowing for customizable and efficient lateral filling of metal plugging material into perforations, with the ability to retrieve and recondition the heater for reuse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cement is used for plugging wells or sealing casing, then the sealing function is achieved, but cement mixes with drilling mud or downhole fluids causing early failure due to channeling
Solution Approach 1:
The invention changes the material parameter from cement to molten metal, which has fundamentally different physical and chemical properties. The molten metal maintains its composition stability in downhole environments, does not mix with drilling mud or fluids, and eliminates channeling issues that plague cement plugs.
2Ease of operation
If cement is used for plugging, then sealing is achieved, but cement is difficult to pump through perforations in joints
Solution Approach 1:
The invention changes the physical state parameter from solid cement to liquid molten metal. The molten metal flows easily through perforations due to its liquid state and appropriate viscosity, eliminating the pumping difficulties associated with cement while requiring less material to achieve effective sealing.
3Ease of operation
If metal plugs are used instead of cement, then pumping through perforations is easier, but the heater tool cannot be retrieved and reused
Solution Approach 1:
The invention divides the tool into separable components: the heater assembly and the running string. The heater is detached from the running string after use, allowing the running string to be retrieved and reused while the heater remains downhole. This segmentation enables tool reusability and reduces operation time for subsequent jobs.
Solution Approach 2:
The invention implements a strategy where the heater is discarded (left downhole) and the running string is recovered (retrieved and reused). This approach recovers the expensive, reusable components while leaving the consumable heater in place, optimizing cost-effectiveness and reducing operation time for repeat treatments.
4Reliability
If metal plugs are used for sealing, then sealing effectiveness is improved, but material usage and operation costs increase
Solution Approach 1:
The invention changes the material from cement to molten metal, which provides superior sealing effectiveness. The molten metal fills and seals perforations more effectively due to its流动性 and bonding characteristics, while the detachable heater system reduces overall material usage by enabling precise, controlled application.
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
The solution significantly reduces operation time and material usage by enabling larger-scale sealing with less material, allowing for efficient lateral filling and reusability of the heater, thus enhancing the efficiency and cost-effectiveness of well plugging operations.
Implementation Method 1
a heater that comprises thermite... an ignition mechanism that ignites the thermite
Implementation Method 2
melting the meltable plugging material by igniting the thermite... forcing the plugging material against the well casing
Data Source
AI summary
This disclosure describes a device and method of sealing perforations on a well casing inside a subterranean well. The device comprises a generally cylindrical sleeve having an open top and a closed bottom; a heater located inside the sleeve, the heater comprising a thermite mixture; an ignition mechanism that ignites the thermite mixture upon actuation; and a string connected to the heater ignition and detachably engages the sleeve. The method comprises lowering a body of meltable plugging material into the well casing near the perforations; lowering the plugging device into the well casing immediately on top of the body of meltable plugging material; melting the meltable plugging material by igniting the thermite thereby transferring heat to the body of meltable plugging material; forcing the molten plugging material into the perforations by pushing the plugging tool further downhole; cooling the plugging tool and the plugging material until the plugging material solidifies; disengaging the tubing string from the sleeve and retrieving the tubing string with the heater; and removing the sleeve and bismuth remaining in the well casing, but not in the perforations.