Wellbore Junk Catcher with Rearward Jet Nozzles

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Solution Overview

Problem

Current wellbore cleanout tools are ineffective in removing small to medium-sized debris and junks, often requiring multiple trips and failing to ensure a clean wellbore, especially in deviated or horizontal sections, due to design limitations and inability to operate in total mud loss environments.

Innovation Solution

A wellbore cleanout tool with rearward-facing jet nozzles that flush junks into a junk catcher, combined with a solid body design matching the casing drift for effective debris collection and a multi-section gate mechanism to trap objects, capable of operating in total mud loss environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional wellbore cleanout tools are used, then large fish can be removed, but small to medium-sized debris and junks cannot be effectively removed

Engineering Contradiction:
Improvedebris removal effectivenessVSAvoidcleanout operation efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The tool divides the debris capture function into multiple sections: a junk catcher for larger objects, a screen for filtering small to medium-sized debris, and jet nozzles for flushing. This segmentation allows the tool to handle debris of various sizes simultaneously, resolving the contradiction between removing different quantities and sizes of substance while maintaining operational efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The screen is nested within the junk catcher body, and the jet nozzles are integrated into the tool structure. This nesting allows multiple functions (flushing, filtering, and catching) to be combined in a single tool, enabling effective removal of both large fish and small debris without requiring multiple separate operations.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If multiple cleanout trips are made, then wellbore cleanliness can be improved, but time and operational cost increase

Engineering Contradiction:
Improvewellbore cleanliness assuranceVSAvoidcleanout operation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The tool is designed to perform multiple functions in a single trip: the jet nozzles flush debris upward, the screen filters small to medium-sized particles, and the junk catcher secures larger objects. This multi-functionality ensures comprehensive wellbore cleanliness assurance without requiring multiple separate cleanout trips, thereby reducing time loss.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The tool enables continuous debris removal action during a single trip by combining flushing, filtering, and catching mechanisms. The jet nozzles continuously flush debris while the screen and junk catcher simultaneously capture particles of various sizes, ensuring the wellbore is cleaned thoroughly in one continuous operation rather than requiring multiple intermittent trips.

Inventive Principle:
Principle #20Continuity of useful action

3Ease of operation

If conventional tools are used in deviated or horizontal sections, then tool deployment is possible, but debris circulation and removal become difficult

Engineering Contradiction:
Improvetool deployment capabilityVSAvoiddebris removal effectiveness
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The tool uses jet nozzles that direct high-velocity fluid streams to flush debris upward against gravity in deviated or horizontal sections. This hydraulic action overcomes the difficulty of debris circulation in non-vertical wellbores, enabling effective debris removal while maintaining ease of tool deployment and operation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

4Reliability

If total mud loss environment occurs, then conventional circulation-based tools fail, but cleanout operation must continue

Engineering Contradiction:
Improvetool operation reliabilityVSAvoidenvironmental adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The jet nozzles are powered by the tool's own internal fluid system rather than relying on external mud circulation. This self-service capability allows the tool to continue operating and flushing debris even in total mud loss environments where conventional circulation-based tools fail, demonstrating both reliability and adaptability to harsh conditions.

Inventive Principle:
Principle #25Self-service

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

The tool effectively captures junks of various sizes, including large pieces, and ensures wellbore cleanliness by allowing localized flushing, reducing the need for multiple cleanout runs and enhancing tool durability in harsh environments.

Implementation Method 1

The elongated tubular member is adapted to receive pressurized flushing liquid at the rear end... directing the flushing liquid radially outwardly and rearwardly... to thereby direct objects and debris from the wellbore into the annular space

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 2

A multiple-section gate is positioned within the elongated generally cylindrical body member... each gate section being spring biased to pivot downwardly toward generally radial positions which blocks the front end of the generally cylindrical body member

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

means positioned adjacent the apertures in the tapered wall portion at the upper end of the cylindrical body member to filter the upwardly directed liquid to separate debris and other objects therefrom

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP2638238B1Tool for recovering junk and debris from a wellbore of a well
Publication Date: 2019.02.20 SAUDI ARABIAN OIL CO
  • EP2638238B1 patent drawingFigure 1~5
  • EP2638238B1 patent drawingFigure 3~4
  • EP2638238B1 patent drawingFigure 6

AI summary

A downhole tool incorporates a junk catcher with full body casing drift. It is made of an inner tubular member that conveys the hydraulic power or circulating fluid to rearward and outward facing jet nozzles for directly flushing downhole junks in front of the tool (if encountered) into a junk collecting barrel equipped with individual magnets to retain magnetically attractive metal junks. The barrel is made of high grade steel material with outer diameter matching the full drift of wellbore casing. The front, or the lower end of the outer body is addressed with tungsten carbide cutters to effectively handle metal junks in case of milling action is required. The back, or upper end of the barrel has return flow ports equipped with a filter screen to retain small, medium and large size junks while fluid is pumped through the tool.