Continuous Heating Element for Subsea Flowline Branch Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Maintaining continuous thermal management across subsea pipelines with branch structures, such as tees, is challenging due to the need for multiple electrical connections, which can reduce system reliability.

Innovation Solution

A flowline branch structure with an inner branch assembly, an outer branch housing, and a continuous wiring element that extends across the interface between the inner and outer branch assemblies, minimizing the number of electrical connections required and ensuring uninterrupted heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If multiple electrical connections are used across branch structures, then heating can be maintained across the branch, but system reliability decreases due to increased number of connection points

Engineering Contradiction:
Improveheating continuityVSAvoidsystem reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent merges multiple separate electrical connections into a single continuous heating element that spans across the branch structure. The heating element is configured to extend continuously from the first pipe through the branch to the second pipe, eliminating the need for multiple discrete connections and thereby maintaining heating continuity while improving system reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single continuous heating element serves multiple functions simultaneously: it heats the first pipe, heats the branch structure, and heats the second pipe. This multi-functional design replaces what would traditionally require separate heating elements and multiple electrical connections for each component.

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

2Temperature

If traditional branch structures with multiple connections are used, then electrical heating can be provided to each section, but device complexity increases

Engineering Contradiction:
Improveheating coverageVSAvoidnumber of electrical connections
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent combines multiple heating zones into a single integrated heating element. Instead of installing separate heating elements on the first pipe, branch, and second pipe with multiple electrical connections, a single continuous heating element provides thermal management across all components, significantly reducing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If thermal management continuity is maintained across branch structures, then plug formation is prevented, but the structure becomes more complex requiring special wiring arrangements

Engineering Contradiction:
Improveplug preventionVSAvoidwiring arrangement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The heating element is designed to maintain continuous thermal management action across the branch structure. By extending the heating element continuously from the first pipe through the branch to the second pipe without interruption, the system ensures uninterrupted heating that prevents temperature drops and plug formation, while the continuous design itself simplifies the wiring arrangement.

Inventive Principle:
Principle #20Continuity of useful action

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 enhances the reliability of thermal management by reducing the number of interfaces and maintaining continuous heating across branch structures, preventing the formation of plugs and ensuring efficient fluid flow in subsea pipelines.

Implementation Method 1

ETH employs highly-resistive electric wires running along the outer surface of a steel pipeline. Heat produced by passing an electric current along the wires is conducted to the inner surface of the pipeline and from there to the production fluids flowing within.

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

In passive temperature-management systems, the pipeline is thermally insulated, typically by a layered external coating of plastics material or by a sandwich structure employing alternating plastics insulating layers and steel layers.

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3152474B1Branch structures of electrically-heated pipe-in-pipe flowlines
Publication Date: 2018.11.21 ACERGY FRANCE
  • EP3152474B1 patent drawingFigure 1~2
  • EP3152474B1 patent drawingFigure 3~4
  • EP3152474B1 patent drawingFigure 5~7

AI summary

A flowline branch structure (10) has at least one inner branch assembly comprising an inner flowline branch and at least one inner flowline pipe attached to and communicating with the inner flowline branch. At least one outer branch assembly (12) of the flowline branch structure comprises an outer branch housing disposed around the inner flowline branch and at least one outer pipe (14) disposed around the inner flowline pipe and attached to the outer branch housing. A generally annular space is defined between the inner and outer branch assemblies. At least one wiring element including an electrical heating element is disposed in the sealed space on an outer side of the inner branch assembly. The, or each, wiring element extends in one continuous length across an interface between the inner flowline pipe and the inner flowline branch. This reduces the number of connections necessary to create the flowline branch structure.