Drill Pipe Connector With External Welding To Reduce Flow Resistance

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Solution Overview

Problem

Existing drill pipe connectors cause flow-related obstacles and pressure losses due to internal weld beads, leading to increased energy costs and uneven loads, especially in deep drilling applications where minimizing bore diameter is crucial.

Innovation Solution

A connector design with a cylindrical body and central through-bore that separates the connection area from the flow path, avoiding internal weld beads and optimizing the flow transition with a conically widened bore section, allowing for friction welding without post-treatment and maintaining a low flow resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If connectors are manufactured by cutting and butt-friction welded to pipe ends, then manufacturing precision and connection strength are improved, but internal weld beads form causing flow resistance and pressure losses

Engineering Contradiction:
Improveconnection strengthVSAvoidpressure loss
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The invention extracts the harmful welding operation from the flow path by positioning the connector body such that welding occurs only on the external surface. The connector body is designed with a through-bore that allows the drill pipe end to be welded to the connector's external surface, completely separating the welding zone from the internal flow path, thereby eliminating internal weld beads and associated pressure losses

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention moves the welding operation from the internal dimension (inside the pipe) to the external dimension (outside the pipe). By designing the connector to weld to the external surface of the drill pipe end, the welding process is relocated to a different spatial dimension that does not interfere with the internal fluid flow, thus resolving the contradiction between strong connections and low flow resistance

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If connectors are manufactured by cutting rather than formed in one piece, then manufacturing cost and ease of manufacture are improved, but internal weld beads are created requiring post-treatment

Engineering Contradiction:
Improvemanufacturing easeVSAvoidpost-processing effort
Core Design Contradiction:
Ease of manufactureVSEase of repair

Solution Approach 1:

The invention extracts the welding operation from the internal flow path by positioning the connector body such that welding occurs only on the external surface. The connector body is designed with a through-bore that allows the drill pipe end to be welded to the connector's external surface, completely separating the welding zone from the internal flow path, thereby eliminating internal weld beads and associated pressure losses

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention moves the welding operation from the internal dimension (inside the pipe) to the external dimension (outside the pipe). By designing the connector to weld to the external surface of the drill pipe end, the welding process is relocated to a different spatial dimension that does not interfere with the internal fluid flow, thus resolving the contradiction between strong connections and low flow resistance

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Loss of energy

If the connector body is cylindrical with a conically widened bore section, then flow resistance is reduced and turbulence is minimized, but manufacturing complexity increases

Engineering Contradiction:
Improveflow resistanceVSAvoidconnector geometry
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The invention applies local quality by providing different geometric characteristics in different sections of the connector body. The initial section has a cylindrical geometry for easy manufacturing and connection, while the end section features a conically widened bore for optimized flow. This localized geometric variation improves flow characteristics only where needed without unnecessarily complicating the entire connector structure

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention uses curved surfaces, specifically a conically widened bore section, to optimize fluid flow through the connector. The conical curvature creates a smooth transition that reduces turbulence and flow resistance compared to a purely cylindrical geometry, while still maintaining manufacturability through standard machining processes

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 connector reduces turbulence and flow resistance, eliminating the need for costly post-processing and minimizing pressure losses, ensuring efficient fluid flow and reduced energy consumption in drill pipe connections.

Implementation Method 1

the connectors are typically butt-friction welded to the pipe ends

Methodology Applied
Scientific EffectFriction welding: Friction Welding

Data Source

PatentEP2021672B1Connector for drill pipes, and drill pipe equipped with a connector
Publication Date: 2019.08.14 BRODER MATHIAS
  • EP2021672B1 patent drawingFigure 1~2
  • EP2021672B1 patent drawingFigure 3~4

AI summary

Disclosed is a connector for drill pipes, which can be integrally connected, especially welded, to a longitudinal end of a drill pipe (B). Said connector (10) comprises a substantially cylindrical member (1) that is provided with a central through-bore (5). A connecting section (2) for a correspondingly embodied connecting section of a second connector is configured at one longitudinal end of said substantially cylindrical member (1) while the second longitudinal end of the member (1) is equipped with a coupling part (7) that is to be positively connected to a longitudinal end of a drill pipe (B). The coupling part (7) is embodied in an insertion section (3) of the member (1) which faces away from the connecting section (2) and in which the central through-bore (5) continues, the coupling part (7) radially protruding from the insertion section (3). The central through-bore (5) is fitted with a drilling section (6) that is flared towards the free end of the insertion section (3) adjacent to a cylindrical drilling section.