Tandem Bridge Plug Locking Mechanism for Single-Run Setting
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Solution Overview
Problem
Current methods for setting tandem retrievable bridge plugs in the well service industry require separate runs for each plug, making it inefficient and impractical to set two plugs simultaneously, especially in emergency situations, and hinder single-run pressure testing for leak location in casing strings.
Innovation Solution
A tandem releasable bridge plug system where the upper and lower plugs are initially disabled by a lock that can be unlocked from the surface, allowing sequential setting and testing of both plugs on a single drill pipe string, with the lower plug set first and the upper plug enabled after the lower is secured, enabling simultaneous operational control without affecting the lower plug.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate runs are used to set each bridge plug, then each plug can be properly set and controlled, but the time required to set two plugs doubles and operational efficiency decreases
Solution Approach 1:
The patent combines two separate plug-setting operations into a single run by connecting two bridge plugs (upper plug 1U and lower plug 1L) to the same drill pipe string. The drill pipe string serves both plugs simultaneously, allowing both to be set, tested, and controlled in one continuous operation rather than requiring two separate runs.
Solution Approach 2:
The system segments the control of each plug independently through a disconnectable connector (2L, 2U) positioned between the upper and lower plugs. This connector can be selectively disconnected to isolate either the upper or lower plug, allowing independent operation and testing of each plug while maintaining the ability to control both from the surface during a single run.
2Productivity
If both upper and lower plugs are made operable on a single drill pipe string, then setting time is reduced, but interference between the two plugs during setting operations occurs
Solution Approach 1:
The disconnectable connector (2L, 2U) acts as an intermediary element between the upper plug (1U) and lower plug (1L). This connector can be selectively disconnected to prevent mechanical interference between the two plugs during setting operations. When the connector is disconnected, rotational and axial movements applied to the drill pipe string affect only one plug at a time, eliminating the interference problem while maintaining the ability to operate both plugs from a single drill pipe string.
3Ease of operation
If the upper plug is initially disabled by a lock, then the lower plug can be set without interference, but an additional unlocking step is required
Solution Approach 1:
The upper plug (1U) and its disconnectable connector (2U) are preliminarily disabled by a lock (5) before the setting operation begins. This preliminary locking prevents any accidental or premature operation of the upper plug during the lower plug setting process. The lock is designed to be released by a simple ball drop mechanism, which is a straightforward operation that does not significantly add to the overall procedure complexity.
Solution Approach 2:
The lock (5) uses a ball (51) and ball seat axial sleeve (52) mechanism that is simple, reliable, and easy to operate. The ball drop unlocking mechanism is a classic, proven design that requires minimal complexity while providing effective temporary disabling of the upper plug. The simplicity of this locking mechanism means it adds minimal operational steps while providing robust protection against interference.
Data Source
AI summary
A method of setting a tandem releasable bridge plug system in a casing includes assembling a tandem bridge plug string including a lower bridge plug on a lower, disconnectable connector, an upper bridge plug on an upper, disconnectable connector which both are initially disabled by a lock and unlockable from topsides, and running in the tandem plug string on a drill pipe string until the lower plug is at its setting target depth; setting and shutting the lower plug; disconnecting the upper plug from the lower plug; pulling up the upper plug to its upper setting target depth; enabling the upper plug by releasing the lock; setting and shutting the upper plug; disconnecting the drill pipe string from the upper plug.