Spear Type Blowout Preventer Seal Backup
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Solution Overview
Problem
In oilfield operations, existing tubular gripping tools face challenges in well control during incidents when both the draw works and passive seals fail, making it difficult to shut in the well and maintain fluid pressure.
Innovation Solution
A blowout preventer assembly with an expandable seal on the tubular gripping tool's spear, which can be selectively expanded using a drive system to create a backup seal between the spear and the tubular's inner wall, ensuring well control during failures of primary seals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a passive seal is used about the spear to create a seal against the tubular's inner diameter, then the seal operates reliably under normal pressure differentials, but the seal fails to provide adequate well control when both the draw works and passive seal fail during a well control incident
Solution Approach 1:
The patent applies beforehand cushioning by providing an expandable seal as a pre-positioned backup system that remains dormant during normal operations but can be activated to provide well control when the primary passive seal fails during a well control incident. This ensures reliability without requiring complex active systems under normal conditions.
Solution Approach 2:
The seal system is segmented into two independent components: a passive seal for normal operations and an expandable seal for emergency well control. This segmentation allows each component to be optimized for its specific function while maintaining overall system reliability.
2Reliability
If an expandable seal is added as a backup to the primary seal, then well control capability is improved during failures, but the device complexity and number of components increase
Solution Approach 1:
The patent merges the passive seal and expandable seal into a single integrated seal system about the spear, where both sealing mechanisms work together to provide comprehensive well control capability. The expandable seal is positioned to engage the same tubular inner diameter as the passive seal, creating a unified backup system.
Solution Approach 2:
The seal system is designed with multi-functionality, where the same spear and seal assembly can operate in two modes: passive sealing during normal operations and active expandable sealing during well control incidents. This universal design reduces the need for separate systems while maintaining reliability.
3Reliability
If the expandable seal is selectively operable using a drive system, then the seal can be activated on demand for well control, but the ease of operation and response time may be affected
Solution Approach 1:
The expandable seal system is designed to be self-activating through a drive mechanism that responds to pressure differential or operational signals, reducing the need for complex external control systems. The seal can be activated on-demand through the drive system while maintaining ease of operation through automatic or semi-automatic triggering mechanisms.
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 expandable seal effectively shuts in the well by creating a reliable seal between the spear and the tubular's inner wall, even when primary seals fail, thereby maintaining well control and fluid pressure.
Implementation Method 1
a primary seal about the spear to create a seal between the spear and the inner wall of the tubular, the primary seal being expandable in response to at least operationally generated fluid pressure differential in the tubular
Implementation Method 2
an expandable seal carried on the spear and expandable to seal between the spear and the tubular's inner wall
Data Source
AI summary
A blow out preventer for operating between a spear of a tubular gripping tool and a tubular gripped by the tool includes: an expandable seal carried on the spear and expandable to seal between the spear and the tubular's inner wall, the expandable seal being operable as a back up to a primary seal operable between the spear and the tubular's inner wall. A tubular gripping tool and a method may include the blow out preventer.