Equalization Valve for Well Pressure Control Device

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Solution Overview

Problem

Current methods for installing and retrieving pressure control device components from subterranean well systems are inefficient, lacking a convenient and effective means for pressure equalization during these operations.

Innovation Solution

The implementation of an equalization valve system that allows for selective fluid communication between the annulus and the interior of the tubular string, utilizing a mandrel with a biasing device and flow restriction to control fluid flow and create pressure differentials, enabling the valve to switch between open and closed configurations based on fluid flow rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional methods are used to install and retrieve pressure control device components, then the device structure remains simple, but the installation and retrieval efficiency is low and pressure equalization cannot be maintained

Engineering Contradiction:
Improveinstallation and retrieval efficiencyVSAvoiddevice structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The device is divided into separate functional modules: an equalization valve assembly for pressure equalization, a running tool for installation and retrieval operations, and a pressure control device with bearings and seals. This segmentation allows each component to perform its specific function efficiently while maintaining overall system manageability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The equalization valve acts as an intermediary component that mediates between the annulus and the interior of the tubular string, enabling controlled fluid communication to equalize pressure during installation and retrieval operations without requiring complex manual pressure control procedures.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If pressure equalization is not maintained during component installation and retrieval, then the device structure remains simple, but pressure differentials cause isolation of annulus sections and operational complications

Engineering Contradiction:
Improvepressure equalization maintenanceVSAvoidpressure control mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The equalization valve is designed to automatically respond to pressure differentials between the annulus and the tubular string interior. When pressure equalization is needed, the valve opens to allow fluid flow; when pressures are balanced, the valve closes. This self-regulating mechanism maintains pressure equalization without requiring complex external control systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The equalization valve utilizes fluid pressure differentials (hydraulic principles) to control the opening and closing of the valve. The biasing device and flow restriction work together to create controlled pressure differentials that automatically equalize pressure between the annulus and the tubular string interior during installation and retrieval operations.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Ease of operation

If fluid communication is not provided between annulus and tubular string interior, then the device structure remains simple, but pressure differentials cannot be controlled and component installation/retrieval becomes difficult

Engineering Contradiction:
Improvecomponent installation and retrievalVSAvoidfluid communication control mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The equalization valve transitions between static (closed) and dynamic (open) states based on operational requirements and pressure differentials. The valve can open to provide fluid communication when pressure equalization is needed during installation or retrieval, and close when pressures are balanced, providing dynamic control of fluid communication without complex mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The flow restriction component modifies the flow characteristics by creating a controlled restriction in the fluid passage. This parameter change (flow restriction) allows the system to control the rate and amount of fluid communication between the annulus and tubular string interior, enabling smooth pressure equalization during component installation and retrieval operations.

Inventive Principle:
Principle #35Parameter changes

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

Facilitates efficient installation and retrieval of pressure control device components by maintaining pressure equalization, allowing for fluid communication to prevent isolation of annulus sections and enabling pressure testing, thereby enhancing operational efficiency and reliability.

Implementation Method 1

A biasing device may be provided which acts on the mandrel to return the mandrel to the closed position

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

A flow restriction may be provided in the passage through the equalization valve housing assembly

Methodology Applied
Scientific EffectPressure Drop: Pressure Drop

Data Source

PatentEP3695092B1Pressure equalization for well pressure control device
Publication Date: 2021.09.01 WEATHERFORD TECHNOLOGY HOLDINGS LLC
  • EP3695092B1 patent drawingFigure 1
  • EP3695092B1 patent drawingFigure 2
  • EP3695092B1 patent drawingFigure 3

AI summary

A method can include positioning a tubular string in a riser string including an outer housing of a pressure control device and an annular seal operable to prevent flow through an annulus between the tubular and riser strings, the tubular string including an equalization valve and a running tool operable to convey a releasable assembly of the pressure control device through the riser string, and opening the equalization valve, thereby permitting fluid communication between the annulus and a flow passage extending longitudinally through the tubular string. A system can include a riser string including an annular blowout preventer with an annular seal, a tubular string including a running tool and an equalization valve releasably attachable to a releasable assembly including an annular seal, and the equalization valve selectively preventing and permitting fluid communication between a flow passage of the tubular string and an annulus between the annular seals.