Downhole Plug Injection Tool for Lost Circulation Zones
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Solution Overview
Problem
Lost circulation during drilling operations leads to significant time and financial losses due to the inability of existing methods to effectively plug lost circulation zones, as chemicals and cement activation times often exceed the time it takes for them to reach the desired location, resulting in fluid loss into fractures.
Innovation Solution
The use of downhole plug injection tools with axial sealing elements and a fabric strip to hold plugging materials, such as chemicals or cement, in place until they solidify, effectively sealing lost circulation zones by positioning seals above and below the affected area and using flexible ties and fabric to maintain the plugging material within the wellbore.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemicals or cement are sent to plug lost circulation zone, then plugging material reaches the fracture zone, but activation or solidification occurs after the material has already been lost into fractures away from wellbore
Solution Approach 1:
The patent applies preliminary action by pre-positioning sealing elements (packers or bridge plugs) at the lost circulation zone before injecting the plugging material. This ensures that when the material is injected, it is immediately contained and can activate or solidify in place without being lost into fractures. The sealing elements are installed in advance to create a containment environment for the subsequent plugging material injection.
Solution Approach 2:
The patent uses an intermediary containment mechanism (sealing elements and fabric strip) between the wellbore and the fracture zone. This intermediary structure prevents direct loss of plugging material into fractures while allowing the material to activate or solidify in the controlled space between the seals, thereby resolving the timing mismatch between material delivery and activation.
2Quantity of substance
If conventional methods are used to send chemicals or cement, then material is delivered to lost circulation zone, but material is lost inside fractures away from wellbore before solidification
Solution Approach 1:
Sealing elements are installed in advance at the lost circulation zone to create a containment barrier before plugging material injection. This preliminary containment prevents material loss into fractures during the injection and activation process, ensuring maximum material retention at the intended plugging location.
Solution Approach 2:
The patent employs a fabric strip as a flexible containment barrier between the sealing elements. This fabric strip acts as a flexible shell that prevents plugging material from escaping into fractures while allowing for some deformation and adaptation to the wellbore geometry, thereby improving material retention without compromising containment effectiveness.
3Duration of action of stationary object
If activation time is extended to ensure proper solidification, then material solidifies completely, but material reaches fracture zone and is lost before activation completes
Solution Approach 1:
Sealing elements are pre-installed at the lost circulation zone to create a containment environment before material injection. This preliminary containment allows the material to remain in place during transport and activation, preventing loss into fractures even during the extended solidification period, thereby decoupling the solidification duration from material loss risks.
Solution Approach 2:
The sealing elements and fabric strip serve as an intermediary containment system that isolates the plugging material from the fracture zone during the entire activation process. This intermediary barrier allows extended solidification times without material loss, as the containment system prevents transport of material into fractures regardless of activation duration.
4Adaptability or versatility
If temperature-triggered reactions are used for chemical activation, then activation can be controlled, but activation may be off and occur at incorrect timing
Solution Approach 1:
The containment system provides feedback control for activation timing by ensuring material remains in place until activation is complete. The sealing elements and fabric strip create a closed system where temperature-triggered reactions can proceed without material loss, allowing for more precise control and monitoring of activation timing based on actual downhole conditions rather than predicted timing alone.
Data Source
AI summary
A method of plugging a section of a wellbore wall includes sending a plug injection tool to a downhole location proximate the section of the wellbore wall, setting a first seal below the section of the wellbore wall using the plug injection tool, and setting a second seal above the section of the wellbore wall using the plug injection tool. A plugging material is pumped between the first and second seals and held there until it solidifies.