Pressure-Actuated Recirculation Valve for Continuous Wax Prevention
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Solution Overview
Problem
Existing chemical injection methods for reducing wax buildup in production tubing require stopping well production and using service equipment for circulating treatment fluids, which is costly and time-consuming.
Innovation Solution
A recirculation valve with a flow mandrel, concentric sleeve, and actuation chamber that opens and closes based on fluid pressure, allowing forward circulation of treatment fluids without unseating a downhole pump, using a collet lock and return spring to control the sleeve's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If service equipment is used to circulate treatment fluid through production tubing, then wax buildup is reduced, but well production must be stopped and operational costs increase
Solution Approach 1:
The recirculation valve enables the well system to circulate treatment fluid through itself without external service equipment. The valve automatically directs fluid from the tubing through the pump and back up the annulus, allowing the system to service itself continuously during production without requiring external intervention or shutdowns.
Solution Approach 2:
The valve dynamically changes flow direction based on operational needs. It can switch between allowing normal production flow and enabling recirculation mode, adapting the system's behavior to maintain both production continuity and wax prevention without manual intervention.
2Reliability
If service equipment is deployed for chemical injection, then treatment fluid circulation is achieved, but the process becomes time-consuming and costly
Solution Approach 1:
The valve eliminates the need for external service equipment by enabling the well's own pumping system to circulate treatment fluid. This self-service mechanism allows continuous circulation during normal production operations, eliminating time losses associated with deploying and operating external service equipment.
Solution Approach 2:
The valve enables continuous circulation of treatment fluid throughout the production process rather than requiring intermittent service interventions. The recirculation can occur continuously or on a regular basis without stopping production, maintaining constant protection against wax buildup.
3Ease of operation
If downhole pump is unseated for treatment fluid circulation, then fluid can be injected, but production must be stopped
Solution Approach 1:
The system uses the existing downhole pump to provide both production and treatment fluid circulation functions. The recirculation valve directs fluid through the pump without requiring the pump to be unseated or removed, allowing the pump to continuously provide both production lift and treatment fluid circulation during normal production operations.
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
Enables continuous and efficient circulation of treatment fluids to prevent wax buildup without stopping production, reducing operational costs and time, and allowing for multiple cycles of operation.
Implementation Method 1
a return spring for biasing the sleeve into its closed position
Implementation Method 2
the opening force is provided by greater than about 200 psi, and preferably about 800 to about 1000 psi
Data Source
AI summary
A downhole recirculation valve includes a flow mandrel and a pressure actuated concentric sliding sleeve which opens and closes a fluid recirculation port. The sleeve and mandrel are releasably locked together with a collet. A return spring provides a biasing force to maintain the sleeve in a closed position. The valve may be repeated opened and closed with pressure. Also disclosed is a method of circulating a treatment fluid downhole through a tubing string with a recirculation valve configured to be actuated by fluid pressure within the tubing string, and having an opening force requirement and a maintenance force requirement which is less than the opening force requirement.