Multi-Position Lockable Sliding Sleeve for Fracturing Tools
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gravel packing and fracturing tools often experience well swabbing issues when picking up the inner string, leading to a drop in formation pressure due to fluid loss and design flaws in valve mechanisms, such as flapper valves and shear pins, which can inadvertently close, causing significant pressure reduction.
Innovation Solution
A multi-acting circulation valve system that allows switching between squeeze and circulation modes without engaging the wash pipe valve, with a metering device to ensure the wash pipe valve is only closed after a predetermined force is held for a finite time, and a lockable sleeve to prevent gravel return and ensure production flow through the screens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a flapper valve is used in the wash pipe to prevent fluid loss, then fluid loss into the formation is prevented, but the valve inadvertently closes when the inner string is picked up, causing well swabbing and formation pressure drop
Solution Approach 1:
The valve mechanism is divided into separate functional components: a flapper valve for fluid loss prevention, a retaining sleeve to hold the flapper open, and a shear pin to release the retaining sleeve. This segmentation allows each component to perform its specific function independently, preventing the valve from inadvertently closing during string pickup while maintaining fluid loss prevention capability.
Solution Approach 2:
The retaining sleeve acts as an intermediary mechanism between the flapper valve and the string pickup operation. It holds the flapper valve in the open position during normal operations and only releases it when a deliberate shear pin failure occurs, preventing direct coupling between string pickup and valve closure that would cause swabbing.
2Ease of operation
If the shear pin is set at a low value to ensure the sleeve moves when needed, then the flapper valve can be released, but the sleeve is often inadvertently sheared to release the flapper, causing swabbing
Solution Approach 1:
The shear pin is designed with a specific break strength parameter that is deliberately set higher than normal operational forces but lower than the force required to deliberately release the valve. This parameter change ensures the valve remains stable during normal operations while allowing intentional release when needed, preventing inadvertent shearing during string pickup.
3Ease of operation
If the inner string is picked up while sealed in the packer bore, then the tool can be retrieved, but the formation experiences a drop in pressure due to swabbing
Solution Approach 1:
The retaining sleeve is designed to remain engaged with the flapper valve during the entire string pickup operation, preventing valve closure before the string is fully retrieved. This preliminary action of maintaining valve openness throughout the pickup process prevents formation pressure drop and swabbing while still allowing tool retrieval.
Data Source
AI summary
A fracturing and gravel packing tool has features that prevent well swabbing when the tool is picked up with respect to a set isolation packer. An upper or jet valve allows switching between the squeeze and circulation positions without risk of closing the wash pipe valve. The wash pipe valve can only be closed with multiple movements in opposed direction that occur after a predetermined force is held for a finite time to allow movement that arms the wash pipe valve. The jet valve can prevent fluid loss to the formation when being set down whether the crossover tool is supported on the packer or on the smart collet.