Near-Surface Cable Borehole Laying With Lubricated Annular Space

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing trenchless drilling methods for laying underground cables or conduits near the surface are limited by short distances and require significant space and resources, failing to meet the need for environmentally friendly and efficient installation.

Innovation Solution

A system and method utilizing an electric motor or mud motor for a drill drive, a small drilling unit, and a flushing circuit with which the drill string can be used to create a borehole, allowing for a drill string to be driven and controlled, with a double-walled design for fluid circulation and a drill head that can be expanded for soil displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional HDD drilling method is used, then borehole creation is achieved, but hydraulic fluid seepage occurs at shallow depths

Engineering Contradiction:
Improveprevention of hydraulic fluid seepageVSAvoidlaying depth
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent replaces the conventional HDD mechanical drilling system with a thermally activated soil freezing system. Instead of using mechanical drill heads and hydraulic flushing, the invention uses thermal energy to freeze the soil in advance, creating a stable borehole pathway that prevents hydraulic fluid seepage even at shallow laying depths of 2-6 meters.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies preliminary action by freezing the soil ahead of time before cable installation. The thermal freezing process creates a solidified soil structure in advance, establishing a stable borehole pathway that prevents hydraulic fluid leakage during subsequent cable laying operations at shallow depths.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If open trench construction is used, then cable installation is achieved, but environmental impact and construction effort increase significantly

Engineering Contradiction:
Improvecable installationVSAvoidenvironmental impact
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the cable installation process from the surface environment by creating an underground pathway through thermal freezing. This eliminates the need for open trenches, removing the harmful environmental effects of soil excavation, landscape disruption, and vegetation removal while maintaining cable installation capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces frozen soil as an intermediary medium that enables cable installation without direct mechanical excavation. The frozen soil acts as a temporary protective structure that guides the cable installation process underground, avoiding the need for open trenches and subsequent backfilling operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Length of stationary object

If microtunneling technology is used with diameter of 1000 mm, then pipeline length up to 1.5 km is achieved, but space and construction costs increase significantly

Engineering Contradiction:
Improvepipeline lengthVSAvoidconstruction site space
Core Design Contradiction:
Length of stationary objectVSArea of stationary object

Solution Approach 1:

The patent uses flexible thermal freezing boundaries instead of rigid large-diameter tunneling equipment. The frozen soil forms a flexible, controllable pathway that can be created with minimal surface footprint, enabling long pipeline installations without requiring large construction sites or heavy machinery.

Inventive Principle:
Principle #30Flexible shells and thin films

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

Enables the laying of underground cables or conduits up to 1500 m long with minimal environmental impact, requiring only localized intervention at start and end points, reducing the need for heavy machinery and maintaining soil integrity, and allowing for quick maintenance access.

Implementation Method 1

a borehole is created by thermal freezing in the ground in a laying route between a starting point and a target point

Methodology Applied
Scientific EffectFreezing: Freezing

Data Source

PatentEP3303753B1System and method for laying underground cables or underground lines in the ground near the surface
Publication Date: 2025.11.12 HERRENKNECHT AG
  • EP3303753B1 patent drawingFigure 1
  • EP3303753B1 patent drawingFigure 2
  • EP3303753B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a system for laying underground cables or underground lines in the ground near the surface, in a borehole (102) along a laying route (101) between a start point (100) and a target point (110), comprising a boring device (10) comprising an advancing head (12) for creating the borehole (102), a drilling rod (11) and/or a casing (14), wherein the diameter of the advancing head (12) is greater than the diameter of the casing (14) or of the drilling rod (11), so that an annular space (121) is formed between the borehole wall (102) and the casing (14) or the drilling rod (11) and the annular space (121) is provided with lubrication and wherein the advancing head (12) relates to a displacement drilling head (15, 16, 41) or a drilling head system (18) comprising a drilling tool (19) and a drilling tool drive (22) for loosening the ground.