Blowout Preventer Blade Piercing and Raking Tubular Severing

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Solution Overview

Problem

Current techniques for severing tubulars in wellsite operations are inefficient and require high force, posing challenges in effectively preventing blowouts and ensuring safe environmental practices.

Innovation Solution

The method involves using a blowout preventer with multiple rams and blades, where the blades pierce and rake through the tubular with a cutting surface and shavers to efficiently sever the tubular, reducing the force required and ensuring effective sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If conventional shear rams are used to sever tubulars, then the tubular can be cut, but high force is required which creates operational challenges

Engineering Contradiction:
Improveforce required to sever tubularVSAvoidoperational efficiency
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The blade is segmented into multiple functional zones: a piercing point for initial penetration, a cutting surface for shearing, and shavers for material removal. This segmentation allows each zone to perform a specific function that collectively reduces the overall force required compared to a single conventional shear ram approach

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The piercing point performs preliminary action by creating an initial penetration or hole in the tubular before the main cutting surface engages. This preliminary penetration weakens the tubular structure and reduces the force needed for subsequent cutting operations

Inventive Principle:
Principle #10Preliminary action

2Force

If high force is applied to sever tubulars, then the cut can be achieved, but the complexity of the system increases

Engineering Contradiction:
Improvesevering capabilityVSAvoidsystem complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The blade structure integrates multiple functions into a single component: piercing, cutting, and shavings removal. This multi-functionality eliminates the need for separate devices for each operation, reducing system complexity while maintaining effective severing capability

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

Solution Approach 2:

The piercing point, cutting surface, and shavers are merged into a single integrated blade assembly that is carried by the ram. This combination simplifies the overall system architecture compared to using separate piercing and cutting devices

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If conventional cutting methods are used, then tubulars can be severed, but leakage risks remain during wellsite operations

Engineering Contradiction:
Improvesealing effectivenessVSAvoidleakage risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The shavers on the blade convert harmful material removal into a beneficial sealing mechanism. By removing material and creating a clean, controlled cut surface, the system enables more effective sealing after the cut, reducing leakage risks compared to conventional cutting methods that may leave irregular surfaces

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

This approach allows for efficient severing of tubulars with reduced force and automatic sealing, enhancing safety and environmental protection by minimizing leakage risks during wellsite operations.

Implementation Method 1

piercing the tubular with a piercing point of at least one of the blades such that a portion of the tubular is dislodged therefrom

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

raking through the tubular with a cutting surface of at least one of the blades... the cutting surface may be advanced until the tubular shears apart

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP2576961B1Tubular severing system and method of using same
Publication Date: 2016.12.14 NAT OILWELL VARCO LP
  • EP2576961B1 patent drawingFigure 1
  • EP2576961B1 patent drawingFigure 2A
  • EP2576961B1 patent drawingFigure 2B

AI summary

A method for severing a tubular of a wellbore is provided. The method involves positioning a blowout preventer (108) about a tubular (118), the blowout preventer having a plurality of rams (24) slidably positionable therein and a plurality of blades carried by the rams for engaging the tubular. The method further involves piercing the tubular with a piercing point (300) of at least one of the blades such that a portion of the tubular is dislodged therefrom, and raking through the tubular with a cutting surface (306) of at least one of the blades.