Cable Release System for Drill String Detachment

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Solution Overview

Problem

Existing systems for disconnecting wireline cables from stuck drill strings during wireline drilling operations are ineffective, unreliable, and costly.

Innovation Solution

A cable release system comprising a swivel body, bearing assembly, and release sleeve assembly that uses locking elements and a biasing element to axially move the release sleeve, disengaging the swivel body from the overshot system, allowing for reliable separation of the drilling cable from the drill string.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If known systems and methods are used to disconnect the wireline cable from the drill string, then the drill string can be released, but the process is ineffective, unreliable, and excessively expensive

Engineering Contradiction:
Improvereliability of disconnectionVSAvoidcost of disconnection system
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The cable release assembly is divided into distinct functional segments: a swivel body for cable attachment, a bearing assembly for rotational support, and a release sleeve mechanism for controlled disengagement. This segmentation allows each component to perform its specific function reliably while simplifying the overall system design and reducing costs compared to monolithic previous solutions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The release sleeve acts as an intermediary mechanism between the swivel body and the drill string. It provides a controlled interface that enables reliable disconnection through axial movement, mediating the separation process in a way that is both effective and cost-efficient compared to direct disconnection methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If shear pin solutions are used, then the drill string can be released, but the method is costly and laborious requiring cutting operations

Engineering Contradiction:
Improvespeed of release operationVSAvoidcomplexity of release operation
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The release sleeve mechanism is designed to automatically effect the disconnection of the swivel body from the drill string through its own axial movement. The system performs the release operation autonomously without requiring external cutting tools or complex manual intervention, thereby increasing productivity and simplifying the operation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention replaces the mechanical cutting process (shear pin solutions requiring external cutters) with a purely mechanical disengagement mechanism. The release sleeve's axial movement directly separates the components through designed clearance and interference fit features, eliminating the need for cutting operations and associated equipment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If gravity-driven drop sleeves are used, then the drill string can be released, but the system is ineffective for stuck drill strings

Engineering Contradiction:
Improveeffectiveness of release methodVSAvoidsimplicity of release mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The release sleeve is designed with dynamic characteristics that allow it to respond to applied forces (such as weight or hydraulic pressure) by moving axially. This dynamic behavior enables the mechanism to effectively engage and disengage the swivel body from the drill string under various operating conditions, including stuck drill string scenarios where gravity alone may be insufficient.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention combines multiple functions into a single integrated release mechanism: the release sleeve simultaneously provides mechanical disengagement, seals the central bore, and responds to applied forces. This merging of functions maintains simplicity while improving reliability compared to separate gravity-driven drop sleeve systems.

Inventive Principle:
Principle #5Merging (Combining)

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 and reliable release of stuck drill strings without the need for costly and laborious cutting, overcoming the limitations of previous shear pin solutions and gravity-driven drop sleeves.

Implementation Method 1

a biasing element positioned within the release sleeve and configured to axially move the release sleeve in a second direction

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3730733B1Systems and methods for releasing a portion of a drill string from a drilling cable
Publication Date: 2022.03.09 LONGYEAR TM INC
  • EP3730733B1 patent drawingFigure 1A
  • EP3730733B1 patent drawingFigure 1B
  • EP3730733B1 patent drawingFigure 1C

AI summary

A cable release system for permitting detachment of a drilling cable from a drill string. The cable release system has a swivel body, a bearing assembly, one or more locking elements, and a release sleeve assembly. The swivel body is coupled to a drilling cable. The bearing assembly has a receptacle body that receives a portion of the swivel body and defines openings that receive a portion of corresponding locking elements. The bearing assembly has an outer sleeve that circumferentially surrounds the receptacle body and has a variable inner diameter such that axial movement of outer sleeve controls the radial position of the locking elements relative to the swivel body. The release sleeve assembly can be moved in a distal direction to engage the outer sleeve of the bearing assembly to move the outer sleeve to an axial position in which the swivel body and drilling cable are detachable from the remainder of the drill string.