Drill String Hardfacing Layer Cord Width Variation
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Solution Overview
Problem
The existing resurfacing techniques for drill string elements in oil drilling, which involve hardfacing layers, often require specific filler material compositions and deposition processes, limiting user flexibility and resulting in heterogeneous hardness distributions that affect the service life and performance of the elements.
Innovation Solution
A drill string element with a hardfacing layer comprising filler metal cords of varying widths, deposited to form a substantially continuous layer with hardness variations of less than 10 HRC across different radial thicknesses, using a process that reduces the heat-affected zone and allows for conventional electrode wire usage, enhancing service life and performance independently of filler material composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If conventional hardfacing techniques with specific filler material compositions are used, then the service life of drill string elements is extended, but the user flexibility is limited and heterogeneous hardness distributions are created
Solution Approach 1:
The patent changes the key parameter from filler material composition to cord width variation. By using cords of different widths (narrower and wider portions) instead of relying on specific material compositions, the invention achieves homogeneous hardness distribution while allowing users to select from conventional electrode wires, thus improving both service life and user flexibility
Solution Approach 2:
The invention achieves homogeneous hardness distribution through a specific cord deposition pattern where narrower cords are deposited first, followed by wider cords that overlap and fill the gaps. This systematic arrangement ensures uniform hardness across the hardfacing layer, resolving the contradiction between achieving consistent performance and maintaining user flexibility
2Object-affected harmful factors
If conventional hardfacing deposition processes are used, then the exterior surface is protected against abrasion, but heterogeneous hardness distributions are created affecting service life predictability
Solution Approach 1:
The hardfacing layer is segmented into multiple cords with different widths deposited in a specific sequence. The narrower cords are deposited first to establish a base layer, then wider cords are deposited to overlap and fill gaps. This segmentation approach ensures homogeneous hardness distribution while maintaining effective abrasion resistance
Solution Approach 2:
The narrower cords are deposited first as a preliminary action before depositing the wider cords. This sequence ensures that the foundation layer is established with appropriate hardness characteristics, and the subsequent wider cords build upon this foundation to achieve the desired homogeneous hardness distribution across the entire hardfacing layer
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 solution provides a more uniform and durable hardfacing layer with improved resistance to abrasion, allowing for predictable service life and reduced wear, while using conventional electrode wires, thus enhancing the performance and reliability of drill string elements.
Implementation Method 1
The material is conventionally deposited using a process derived from electric arc welding: a MIG/MAG type torch and a wire forming a fusible electrode whose composition corresponds to the filler material are used.
Implementation Method 2
Other documents deal with the hardness of the coating and/or its homogeneity. Most often, these offer a filler material of a particular composition.
Implementation Method 3
In service, the drill string elements undergo abrasion phenomena due to friction between their exterior surface and the wall of the well, and/or between this surface and drilling debris which goes up the well.
Data Source
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AI summary
The invention relates to a drill string element including at least one refill layer. Said layer includes one or more cords of filler metal, each cord having a width between 1 and 5 millimeters and being laid adjacent to each other so as to form a substantially continuous layer over one area of the element. The hardness in the body of the layer varies by less than 10 HRC over said area.