Drill String Element Flow Channel for Cuttings Bed Removal

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Solution Overview

Problem

In horizontal or slant directional drilling, the formation of a drill cuttings bed in the annular space between the drill hole and the drill string leads to increased torque and pressure losses, potentially causing mud blowouts and fracturing of rock, due to the deposition of drill cuttings and uneven flow velocities.

Innovation Solution

A drill string element with a flow channel system featuring adjustable clear cross sections and nozzles/orifice plates that allow for controlled flow velocities and pressures, enabling the gentle introduction or aggressive swirling of flushing medium to manage drill cuttings and reduce pressure losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the flushing medium flows through the annular space between drill hole and drill string, then drill cuttings are conveyed out of the drill hole, but drill cuttings deposit in zones with low flow velocity forming a drill cuttings bed

Engineering Contradiction:

Improvedrill cuttings evacuationVSAvoiddrilling operation continuity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The invention extracts the harmful drill cuttings bed from the system by introducing a flow channel through the drill string element wall that directs flushing medium to actively remove deposited cuttings from the annular space, preventing bed formation and maintaining continuous drilling operation

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The flow channel acts as an intermediary structure between the drill string interior and the annular space, mediating the flow of flushing medium to selectively remove cuttings without disrupting the overall drilling process or requiring operation interruption

Inventive Principle:

Principle #24Intermediary (Mediator)

2Force

If the drill cuttings bed forms on the bottom of the drill hole, then friction against the bed increases torque of the rotating drill string, but the increased torque can lead to mud blowouts and fracturing of rock

Engineering Contradiction:

ImprovetorqueVSAvoidmud blowout and rock fracturing

Core Design Contradiction:

ForceVSObject-affected harmful factors

Solution Approach 1:

The invention applies preliminary anti-action by introducing flushing medium through the flow channel to prevent drill cuttings bed formation before it can significantly increase torque to dangerous levels, thereby preemptively avoiding mud blowouts and rock fracturing

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The invention converts the harmful effect of potential cuttings bed formation into a benefit by using the flow channel to actively manage cuttings removal, transforming what would be a torque-increasing hazard into a controlled process that maintains safe operating conditions

Inventive Principle:

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

3Speed

If the flow velocity in the annular space increases to prevent cuttings deposition, then pressure losses increase during backflow to the start side, but the increased pressure losses require higher pressure levels that can cause rock fracturing

Engineering Contradiction:

Improveflow velocityVSAvoidpressure level

Core Design Contradiction:

SpeedVSStress or pressure

Solution Approach 1:

The invention segments the flushing medium flow into two paths: one through the drill string interior and another through the flow channel into the annular space, allowing independent optimization of flow velocity and pressure in each path to prevent cuttings deposition without excessive pressure buildup

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flow channel serves as an intermediary that introduces flushing medium directly into the annular space at controlled locations, mediating between the high-pressure internal flow and the annular space to achieve effective cuttings removal at lower overall pressure levels

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution effectively reduces pressure losses and prevents mud blowouts by reintegrating settled drill cuttings into the flow, minimizing the risk of fracturing and maintaining controlled drilling operations, while also allowing for adjustable parameters to suit different drilling conditions.

Implementation Method 1

through which at least a part of the flushing medium flowing through the interior makes its way into an annular space between drill hole wall and main body

Methodology Applied

Scientific EffectFluid flow:

Implementation Method 2

the drill cuttings removed from the pilot drill head mix with the drilling suspension. This suspension then flows with the drill cuttings through the bored drill hole back to the start point

Methodology Applied

Scientific EffectSuspension transport: Suspension

Implementation Method 3

there are zones in which the flow velocity approaches zero, in these zones entrained drill cuttings are deposited, a so-called drill cuttings bed is formed. The consequence of these deposits is an increased torque of the rotating drill string as a result of friction against the drill cuttings bed

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS10941624B2Drill string element

Publication Date: 2021.03.09 HERRENKNECHT AG

AI summary

A drill string element of a drill string, the drill string element configured to keep the pressure in the annular space between the drill string and the drill hole within calculated limits or to keep the pressures prevailing in the annular space or drill string as small as possible. Settled drill cuttings are brought back into the flow or settlement of the drill cuttings is prevented.