Downhole Pulse Generator Removable Agitator Assembly

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Solution Overview

Problem

Conventional downhole pulse generating devices hinder fishing and through-bore operations below the device and are difficult to remove without disconnecting substantial portions of the drill string, limiting their operational flexibility.

Innovation Solution

A downhole tool with a removable agitator assembly that includes a rotor and stator, allowing for the decoupling of the agitator components to facilitate through-bore operations and enable retrieval without removing the entire device from the wellbore, utilizing a latch mechanism or other releasable connections for easy engagement and disengagement with fishing tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the pulse generating device is made as a single integrated unit, then the device structure is simple and reliable, but the device cannot be removed or accessed below without removing substantial portions of the drill string

Engineering Contradiction:
Improveease of removalVSAvoiddevice structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The downhole tool is divided into multiple separable components: a housing, an agitator assembly, and a removable component. The removable component can be detached from the housing to open the longitudinal bore, allowing fishing or through-bore operations below the device without removing the entire tool from the drill string.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the longitudinal bore is kept open for through-bore operations, then fishing activities can be performed below the device, but the agitator assembly cannot function to generate pressure pulses

Engineering Contradiction:
Improvethrough-bore operation capabilityVSAvoidpressure pulse generation
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The tool configuration is made dynamic and adjustable. The removable component can be selectively removed to enable through-bore operations or reinstalled to restore pressure pulse generation capability. This allows the system to adapt to different operational requirements at different times.

Inventive Principle:
Principle #15Dynamics

3Volume of moving object

If the agitator assembly is made compact to reduce drill string displacement, then the device size is minimized, but the agitator components cannot be easily separated for through-bore operations

Engineering Contradiction:
Improvedevice sizeVSAvoidease of component separation
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The agitator assembly is segmented into the housing and a removable component. This segmentation allows the compact overall device size while enabling easy separation of components when through-bore operations are required, resolving the contradiction between compactness and ease of separation.

Inventive Principle:
Principle #1Segmentation

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 efficient fishing and through-bore activities below the pulse generation device by allowing selective removal and reinstallation of the agitator components, thereby extending the operational range of drilling assemblies and reducing the risk of drill string sticking.

Implementation Method 1

a rotor that is rotated by a fluid moving through the housing

Methodology Applied
Scientific EffectFluid flow-induced rotation: Turbine

Implementation Method 2

create fluctuations in fluid pressure that create vibrations in the drill string

Methodology Applied
Scientific EffectPressure fluctuation-induced vibration: Vibration

Data Source

PatentEP2925950B1Downhole pulse generating device for through-bore operations
Publication Date: 2018.05.23 NAT OILWELL VARCO LP
  • EP2925950B1 patent drawingFigure 1~2
  • EP2925950B1 patent drawingFigure 3~3A
  • EP2925950B1 patent drawingFigure 4

AI summary

A downhole tool comprises a housing having a longitudinal bore and an agitator assembly disposed within the longitudinal bore of the housing. A removable component is disposed within the longitudinal bore and can be removed from the housing so as to at least partially open the longitudinal bore.