Fluid-Driven Latching Mechanism for Core Drilling

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Solution Overview

Problem

Conventional wireline core drilling systems are time-consuming due to slow tripping rates caused by drag from spring-loaded latching mechanisms and hydraulic pressure from drilling fluids within the drill string.

Innovation Solution

A high productivity core drilling system featuring a drill string with variable geometry drill rods, a fluid-driven latching mechanism that prevents dragging, and high-efficiency fluid porting to reduce resistance and enhance fluid flow, allowing the inner core barrel assembly to move quickly through the drill string.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a spring-loaded latching mechanism is used to secure the core sample tube, then the core sample tube can be reliably retained in the drill string, but the latches drag against the interior surface during tripping, slowing down the operation

Engineering Contradiction:

Improvecore sample tube retentionVSAvoidtripping rate

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the spring-loaded mechanical latching mechanism with a hydraulic actuation system. Latch arms are actuated by hydraulic pressure delivered through ports in the core sample tube, allowing the latches to engage and disengage without mechanical spring loading that causes dragging. This substitution eliminates the dragging problem while maintaining reliable retention through fluid-powered actuation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses hydraulic pressure from drilling fluids to actuate the latching mechanism. High-pressure fluid ports are positioned to deliver hydraulic pressure directly to the latch arms, enabling them to move between engaged and disengaged positions. This hydraulic actuation system eliminates the need for spring-loaded mechanisms and prevents dragging during tripping operations.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Adaptability or versatility

If drilling fluid is present inside the drill string during tripping, then the drill string can be used for both drilling and tripping operations, but the fluid creates hydraulic pressure that limits the tripping rate

Engineering Contradiction:

Improvedrill string dual useVSAvoidtripping rate

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent turns the hydraulic pressure problem into a solution by using the drilling fluid pressure to actuate the latching mechanism. High-pressure ports are positioned to receive drilling fluid pressure, which then actuates the latch arms to disengage during tripping. This converts the harmful hydraulic resistance into a useful actuation force, enabling fast tripping while maintaining drill string versatility.

Inventive Principle:

Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent converts the harmful effect of hydraulic pressure resistance into a beneficial actuation force. The drilling fluid pressure that previously slowed tripping is now used to automatically disengage the latches during tripping operations. This converts the harmful hydraulic resistance into a useful mechanism for rapid latch release, improving tripping rate while maintaining dual-use capability.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If the core retrieval assembly moves quickly through the drill string, then tripping time is reduced, but drag and hydraulic pressure resistance increase

Engineering Contradiction:

Improvetripping speedVSAvoidresistance force

Core Design Contradiction:

ProductivityVSForce

Solution Approach 1:

The patent uses hydraulic pressure to overcome the drag and resistance forces during quick tripping operations. By positioning high-pressure ports to receive drilling fluid pressure, the system generates sufficient force to rapidly move the core sample tube through the drill string against resistance. The hydraulic actuation system provides the necessary force multiplication to achieve high tripping speeds despite increased drag forces.

Inventive Principle:

Principle #29Pneumatics and hydraulics

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

Significantly reduces the time required for tripping the core sample tube in and out of the drill string, increasing drilling productivity and efficiency by minimizing resistance and hydraulic pressure impacts.

Implementation Method 1

the movement of many conventional core retrieval assemblies within the drill string may create a hydraulic pressure that limits the rate at which the core sample tube may be tripped in and out of the borehole

Methodology Applied

Scientific EffectHydraulic pressure: Pressure Gradient

Implementation Method 2

high efficiency fluid porting to reduce resistance and enhance fluid flow

Methodology Applied

Scientific EffectFluid flow:

Data Source

PatentUS8333255B2High productivity core drilling system

Publication Date: 2012.12.18 BOART LONGYEAR MANUFACTURING & DISTRIBUTION INC

AI summary

High productivity core drilling systems include a drill string, an inner core barrel assembly, an outer core barrel assembly, and a retrieval tool that connects the inner core barrel assembly to a wireline cable and hoist. The drill string comprises multiple variable geometry drill rods. The inner core barrel assembly comprises a non-dragging latching mechanism, such as a fluid-driven latching mechanism that contains a detent mechanism that retains the latches in either an engaged or a retracted position. The inner core barrel assembly also comprised high efficiency fluid porting.