Downhole Pulsation System Reduces Friction via Pressure Pulses

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Solution Overview

Problem

Conventional downhole drilling systems face challenges with frictional resistance and tool string advancement, particularly in horizontal drilling, where coiled tubing is prone to buckling and friction lock-up, and existing cavitation devices lack controlled, tunable pressure pulses.

Innovation Solution

A downhole pulsation system comprising a valve sub housing, lobed insert, mandrel cap, and rotor/stator assembly that generates pressure pulsations by intermittently obstructing fluid flow through lobe features, reducing friction and facilitating tool string advancement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If coiled tubing is used for downhole operations, then flexibility and ease of deployment are improved, but susceptibility to buckling and friction lock-up increases

Engineering Contradiction:

Improveease of deploymentVSAvoidresistance to buckling and friction lock-up

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent employs a pulsation generator that creates mechanical vibrations and pressure pulses in the drilling fluid. These vibrations are transmitted through the coiled tubing to reduce friction between the tubing and wellbore wall, preventing friction lock-up and enabling deeper horizontal drilling operations while maintaining coiled tubing's operational flexibility

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The pulsation generator produces periodic pressure pulses in the drilling fluid at controlled frequencies. This periodic action creates cyclic expansion and contraction of the coiled tubing, which prevents buckling by maintaining dynamic motion and reduces friction through intermittent lifting forces that counteract the weight and friction of the tubing string

Inventive Principle:

Principle #19Periodic action

2Productivity

If conventional cavitation or vibration devices are used, then some pulsation or vibration is generated to assist advancement, but controlled and tunable pressure pulses cannot be achieved

Engineering Contradiction:

Improveadvancement capabilityVSAvoidcontrolled and tunable pressure pulses

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The pulsation generator incorporates adjustable control mechanisms that allow operators to dynamically modify the frequency, amplitude, and duration of pressure pulses. This dynamic adjustability enables optimization of pulsation parameters for different drilling conditions, formation types, and wellbore configurations, achieving both productivity improvement and adaptability

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system allows changing key parameters of the pressure pulses including frequency, amplitude, and pulse width. By adjusting these parameters, the system can adapt to various drilling scenarios, optimize friction reduction effectiveness, and prevent both buckling and friction lock-up across different operational conditions

Inventive Principle:

Principle #35Parameter changes

3Reliability

If extended reach tools are used with coiled tubing, then buckling resistance is improved, but device complexity increases

Engineering Contradiction:

Improveresistance to bucklingVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The pulsation generator acts as an intermediary device that transmits controlled vibrations and pressure pulses through the drilling fluid to the coiled tubing string. This intermediary approach prevents buckling and friction lock-up without requiring direct mechanical modification of the coiled tubing or addition of complex extended reach tools, thereby maintaining system simplicity while improving reliability

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

The system effectively reduces friction on tool strings, allowing for deeper wellbore penetration and preventing buckling by creating controlled pressure pulses, thereby enhancing drilling efficiency and preventing tool string lock-up.

Implementation Method 1

generates pressure pulsations by intermittently obstructing fluid flow through lobe features

Methodology Applied

Scientific EffectPressure pulsation:

Implementation Method 2

intermittently obstructing fluid flow through lobe features

Methodology Applied

Scientific EffectFluid flow interruption:

Implementation Method 3

reducing friction acting on a tool string by generating and utilizing pressure pulsations

Methodology Applied

Scientific EffectFriction reduction: Friction

Data Source

PatentUS10648239B2Downhole pulsation system and method

Publication Date: 2020.05.12 ELFAR TALAL

AI summary

The present technology is a downhole pulsation system for reducing friction on a drill string by generating pressure pulsations. The system includes a valve housing attachable to the drill string, and includes a housing bore for passage of fluid. A lobed insert is fittable inside the valve housing, and includes an insert bore for passage of fluid, and a lobe extending therein. A mandrel cap includes a cap bore therethrough, and at least one port in communication with the cap bore. The mandrel cap has a portion rotatably receivable in the insert bore so that the port is alignable with the lobe. A drive linkage connects the mandrel cap to a rotor of a rotor/stator drive. Fluid flow is intermittently allowed to pass from the insert bore through the port upon rotation of the mandrel cap by the rotor. Pulse frequency is controllable by changing the lobe insert or sleeve.