Flexible Agitator Valve Seat for Downhole Misalignment Relief

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional friction reduction tools in drillstrings suffer from angular misalignment between valve bodies, leading to elevated point loads and potential damage, reducing operational life due to manufacturing tolerances and practicalities.

Innovation Solution

Incorporating a flexible valve seat made of elastomeric material or mechanical biasing elements to permit angular misalignment between valve bodies, allowing one or both to flex relative to the housing, thereby reducing point loads and maintaining central axis alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid valve body connection is used in the agitator, then structural strength and alignment precision are improved, but angular misalignment between valve bodies increases leading to elevated point loads and potential damage

Engineering Contradiction:
Improvestructural strengthVSAvoidoperational life
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent employs a flexible valve seat made of elastomeric material that acts as a compliant element between the valve body and the adapter. This flexible component accommodates angular misalignment while maintaining the seal and structural integrity, preventing elevated point loads that would occur with rigid connections. The flexible valve seat absorbs the misalignment stresses, thereby extending the operational life of the agitator components.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent changes the physical parameter of the valve seat from rigid to flexible by using elastomeric material with specific durometer ratings (60-90 Shore A). This parameter change allows the valve seat to deform and accommodate angular misalignment between valve bodies, reducing point loads while maintaining sufficient structural strength for reliable operation.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a flexible valve seat is used to permit angular misalignment, then wear and fracture damage are reduced, but manufacturing precision and alignment control become more challenging

Engineering Contradiction:
Improveoperational lifeVSAvoidalignment control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The flexible valve seat serves as a compliant element that compensates for manufacturing tolerances and angular misalignment. By using elastomeric material, the design accepts that perfect alignment cannot be achieved through manufacturing alone, and instead uses the flexibility of the valve seat to adapt to the actual alignment conditions, thereby reducing wear and fracture damage.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The flexible valve seat acts as a pre-designed cushioning element that anticipates and absorbs the effects of angular misalignment before it can cause damage. The elastomeric material is selected to provide appropriate compliance, cushioning the impact of misalignment and preventing the elevated point loads that would lead to wear and fracture.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Manufacturing precision

If rigid connections are used between valve bodies and adapters, then alignment precision is maintained, but frictional forces and point loads increase causing component damage

Engineering Contradiction:
Improvealignment precisionVSAvoidcomponent durability
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The flexible valve seat replaces the rigid connection interface with a compliant elastomeric element. This allows the connection to maintain alignment precision through the flexibility of the material while simultaneously reducing frictional forces and point loads by allowing micro-adjustments and deformations that accommodate manufacturing tolerances without transmitting damaging stresses.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The valve seat assembly uses composite construction combining elastomeric material with reinforcement elements (such as fabric or metal inserts) to achieve both flexibility and sufficient structural strength. This composite approach allows the valve seat to be compliant enough to reduce point loads while maintaining the mechanical strength needed for durable operation.

Inventive Principle:
Principle #40Composite materials

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

Minimizes wear and fracture-related damage, extending the operational life of the agitator components by allowing flexible movement and reducing frictional forces.

Implementation Method 1

a flexible valve seat positioned in the first receptacle of the first valve adapter between the first valve body and the first valve adapter and wherein the flexible valve seat is configured to permit the first valve body to flex relative to the first valve adapter

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4536930B1Downhole friction reduction systems having a flexible agitator
Publication Date: 2026.03.25 NAT OILWELL VARCO LP
  • EP4536930B1 patent drawingFigure 1
  • EP4536930B1 patent drawingFigure 2
  • EP4536930B1 patent drawingFigure 3A~3B

AI summary

An agitator deployable in a wellbore includes a housing including a central axis and a central passage, a valve including a first valve body having a first contact face and a second valve body permitted to rotate relative to the first valve body and having a second contact face configured to contact the first contact face, a first valve adapter including a first receptacle which receives at least a portion of the first valve body to couple the first valve adapter to the first valve body, and a flexible valve configured to permit the first valve body to flex relative to the first valve adapter whereby an angular misalignment may form between a central axis of the first valve body and a central axis of the first valve adapter.