Instrumented Drill String Element Hole Configuration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional drill string elements face challenges in efficiently transmitting electrical energy and measurement signals due to resistance to drilling forces and complexity in connecting elements, particularly with existing cable protection arrangements that are difficult to produce and prone to stress concentrations.

Innovation Solution

A drill string element with a tubular body featuring a unique hole configuration that allows a flexible sheath to assume a helical shape, reducing stress concentrations and improving resistance to drilling forces, and a junction portion design for easy assembly and signal transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cable is housed in a tubular sheath pressed against the inner wall of the tube, then the cable is protected, but the arrangement is difficult and expensive to produce

Engineering Contradiction:

Improvecable protectionVSAvoidproduction difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the cable from the traditional housed arrangement and allows it to extend freely along the central axis of the tubular body. The cable is positioned in a longitudinal hole that opens onto the inner surface, eliminating the need for complex sheathing while maintaining cable protection through the structural design of the body itself.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of enclosing the cable within a sheath (conventional approach), the patent inverts the arrangement by allowing the cable to extend freely along the central axis with holes opening onto the inner surface. This inversion simplifies manufacturing while maintaining the protective function through the tubular body structure.

Inventive Principle:

Principle #13The other way round (Inversion)

2Strength

If a helical sheath arrangement is used, then the cable has good resistance to tensile and compressive forces, but stress concentrations occur at the transition from helical to rectilinear arrangement

Engineering Contradiction:

Improveresistance to tensile and compressive forcesVSAvoidstress concentrations

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent segments the cable arrangement into distinct zones: a first portion extending along the central axis with holes opening onto the inner surface, and a second portion extending freely along the central axis. This segmentation allows each portion to be optimized independently, eliminating the need for helical sheathing while maintaining strength through the structured hole arrangement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces the mechanical helical sheath structure with a simpler arrangement of longitudinal holes opening onto the inner surface. This substitution eliminates the complex helical geometry that causes stress concentrations while maintaining adequate resistance to tensile and compressive forces through the distributed hole pattern.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If conventional cable arrangements are used, then the structure is simple, but the resistance to drilling forces is insufficient

Engineering Contradiction:

Improvestructural simplicityVSAvoidresistance to drilling forces

Core Design Contradiction:

Device complexityVSStrength

Solution Approach 1:

The patent creates a composite structure combining the tubular body with strategically positioned longitudinal holes that open onto the inner surface. This composite arrangement provides both structural simplicity and enhanced resistance to drilling forces by distributing mechanical loads through the hole pattern and tubular geometry.

Inventive Principle:

Principle #40Composite materials

4Productivity

If elements are connected along the drill string, then the drill string can be extended, but the complexity of connecting various elements increases

Engineering Contradiction:

Improvedrill string extension capabilityVSAvoidconnection complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent designs the tubular body with universal connection features including a first junction portion with external threading and a second junction portion with internal threading. These standardized multi-functional connection elements enable easy assembly and disassembly of drill string components while maintaining structural integrity, reducing connection complexity despite the need for extension.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP2331786B1Instrumented drill string element

Publication Date: 2018.05.02 TUBOSCOPE VETCO FRANCE SAS

Figure 1~3
Figure 4~5B
Figure 6~8

AI summary

Drill string element (1) comprising a tubular and elongate body (2) delimiting an interior surface (15) that longitudinally has at least one portion of revolution (18) and has a first hole (27, 37) formed in this tubular and elongate body (2). This first hole has a first end opening onto the said portion of revolution (18) and near to this first end has a longitudinal axis that intersects the interior surface (15) at an intersection site. The longitudinal axis forms, in projection in a first plane that passes through the central axis (14) of the portion of revolution (18) and that contains the intersection site, a first angle of non-zero value and, in projection in a second plane tangential to the interior surface at the said intersection site, a second angle of non-zero value.