Ballistic Geotechnical Sampling via Hydraulic Piston

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Solution Overview

Problem

Existing offshore cone penetrometer systems require large and expensive equipment, including seabed frames and heave compensators, to collect geotechnical data, limiting depth and increasing costs, as they rely on static insertion methods that are slow and affected by vessel motion.

Innovation Solution

A dynamic delivery system that uses a hydraulic piston and carrier tube to ballistically insert geotechnical tools into the seafloor, eliminating the need for seabed frames and heave compensators by achieving rapid insertion with controlled fluid pressure, allowing for deeper and faster data collection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If static insertion method is used with seabed frame and heave compensator, then vessel motion is compensated and stable platform is provided, but equipment size and cost increase significantly

Engineering Contradiction:
Improvevessel motion compensationVSAvoidequipment size
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the seabed frame and heave compensator from the system by switching to a dynamic insertion method. The cone penetrometer is fired ballistically into the seafloor, eliminating the need for these complex motion compensation devices entirely.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system transitions from static insertion (requiring motion compensation) to dynamic ballistic insertion. The rapid firing method completes penetration before vessel motion significantly affects the tool, making heave compensation unnecessary.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If static insertion method is used, then controlled penetration rate is achieved, but insertion speed is slow and operational time increases

Engineering Contradiction:
Improvepenetration rate controlVSAvoidinsertion speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The system uses a periodic firing mechanism where the cone penetrometer is launched in a single rapid ballistic event rather than gradual static insertion. This periodic action achieves both speed and adequate control for the application.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The penetration rate changes from slow static insertion (∼2 cm/s) to rapid dynamic insertion (meters per second) by changing the fundamental operating parameter from controlled push to ballistic firing, while still obtaining usable geotechnical data.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If large seabed frame is used to immobilize drill string, then drill string remains motionless during insertion, but equipment weight and deployment complexity increase

Engineering Contradiction:
Improvedrill string stabilityVSAvoidseabed frame weight
Core Design Contradiction:
Stability of the object's compositionVSWeight of stationary object

Solution Approach 1:

The patent eliminates the heavy seabed frame (∼20,000 lbs) by using dynamic insertion. The cone penetrometer is fired from the vessel and penetrates the seafloor independently without requiring the drill string to be immobilized by a seabed frame.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cone penetrometer is pre-positioned on the vessel and fired in advance before the drill string needs to be stabilized. This preliminary ballistic action completes the penetration task without requiring subsequent stabilization equipment.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If conventional deployment system is used, then stable platform is provided for data collection, but equipment cost and vessel size requirements increase

Engineering Contradiction:
Improvedata collection stabilityVSAvoiddeployment system cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cone penetrometer is deployed as a disposable tool that is fired into the seafloor and left there. The expensive seabed frame and heave compensator systems are replaced by this simple, inexpensive ballistic deployment approach that doesn't require recovery or complex support infrastructure.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 cost-effective and rapid collection of geotechnical data and soil samples at greater depths without compromising quality, using smaller vessels and reducing operational time, while being unaffected by vessel heave due to the fast insertion speed.

Implementation Method 1

A dynamic delivery system that uses a hydraulic piston and carrier tube to ballistically insert geotechnical tools into the seafloor, eliminating the need for seabed frames and heave compensators by achieving rapid insertion with controlled fluid pressure

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

the cone sensor portion is installed using a large piston corer weight-head and allowed to free-fall and penetrate into the sediment to about 20 m. During this time, dynamic CPT data is gathered

Methodology Applied
Scientific EffectBallistic motion: Ballistic Pendulum

Data Source

PatentEP3322966B1Downhole stinger geotechnical sampling and in situ testing tool
Publication Date: 2020.07.15 CONOCOPHILLIPS CO
  • EP3322966B1 patent drawingFigure 1A~1B
  • EP3322966B1 patent drawingFigure 2A~2B

AI summary

Offshore system for delivering geotechnical tools to seafloor is described. The system includes a carrier tube that includes an upper end and a lower end, wherein the carrier tube is characterized by an outer diameter and an inner diameter and wherein the inner diameter of the carrier tube defines a hydraulic cylinder; a landing sub shaped or installed at or near the upper end of the carrier tube, wherein inner diameter of the landing sub is smaller than the inner diameter of the carrier tube; a drill bit shaped or installed at or near the lower end of the carrier tube; an extension tube extending upward from the upper end of the carrier tube; an upward seal that seals top portion of the extension tubes; a compression system for introducing compressed fluid under the upward seal; a fixed rod that runs through the hydraulic cylinder; a hydraulic piston disposed in the hydraulic cylinder, wherein the hydraulic piston is moveable along the fixed rod.