Mechanical Filter for Acoustic Telemetry in Subsea Tubing

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Solution Overview

Problem

In subsea environments, accurately and reliably communicating complex data between downhole locations and the surface is challenging due to noise interference and the complexity of implementing communication cables within tubing strings, which limits flow diameter and is prone to damage during emergency disconnects.

Innovation Solution

A subsea installation kit with a subsea tree, acoustic repeaters, and a mechanical filter is used, where the last acoustic repeater is positioned above the subsea tree, and the mechanical filter is integrated into the tubing string to attenuate noise, allowing for effective two-way wireless communication without the need for costly redesigns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cable is placed inside the tubing string for communication, then two-way communication between surface and downhole is enabled, but the flow diameter is limited and the cable is prone to damage during emergency disconnect

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidcable placement complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical cable-based communication system with an acoustic wireless communication system. Acoustic repeaters transmit signals through the tubing string using acoustic waves rather than electrical cables, eliminating the need for physical cable placement inside the tubing string while maintaining two-way communication capability between surface and downhole locations

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces acoustic repeaters as intermediary devices that facilitate communication without direct cable connection. These repeaters transmit acoustic signals through the tubing string, acting as mediators between the surface and downhole tools, thereby enabling communication while avoiding the limitations of direct cable placement

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If acoustic repeaters are positioned above the subsea tree for wireless communication, then communication complexity is reduced, but noise interference from above increases

Engineering Contradiction:

Improvecommunication system complexityVSAvoidnoise interference

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the noise problem from the communication system by introducing a mechanical filter that separates the acoustic signal from noise interference. The filter is positioned in the tubing string above the acoustic repeater and is designed to attenuate noise frequencies while allowing communication frequencies to pass through

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical filter acts as an intermediary component between the noise source and the acoustic repeater. It selectively blocks harmful noise frequencies from reaching the repeater while permitting the desired acoustic communication signals to pass, thereby protecting the communication system from noise interference

Inventive Principle:

Principle #24Intermediary (Mediator)

3Extent of automation

If the tubing string is used for acoustic communication, then wireless communication is achieved, but the uniformity of tubing lengths affects acoustic message propagation

Engineering Contradiction:

Improvewireless communication capabilityVSAvoidtubing length uniformity

Core Design Contradiction:

Extent of automationVSManufacturing precision

Solution Approach 1:

The patent addresses the impact of varying tubing lengths on acoustic propagation by modifying the acoustic characteristics of the tubing string. The mechanical filter and acoustic repeaters compensate for length variations by adjusting the acoustic signal parameters, ensuring consistent communication performance despite non-uniform tubing lengths

Inventive Principle:

Principle #35Parameter changes

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 configuration reduces noise interference, maintaining a similar signal-to-noise ratio and enabling reliable bi-directional communication, even in noisy conditions, without the need for expensive mechanical redesigns or direct cable placement, thus enhancing operational efficiency and safety.

Implementation Method 1

The mechanical filter is designed to cause an attenuation to acoustic signals propagating in the tubing string above the subsea tree

Methodology Applied

Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentUS9441479B2Mechanical filter for acoustic telemetry repeater

Publication Date: 2016.09.13 SCHLUMBERGER TECH CORP

AI summary

A subsea installation kit is described. The kit is provided with a subsea tree, a plurality of tubing sections, a plurality of acoustic repeaters and a mechanical filter. The subsea tree is configured to be coupled to a subsea well having a wellbore. The tubing sections are configured to be connected together to form a tubing string extending from above the tree into the wellbore. The acoustic repeaters are configured to be attached to the tubing string in a spaced apart manner. One of the acoustic repeaters is a last acoustic repeater configured to be attached to the tubing string within or above the tree. The mechanical filter is configured to be connected into the tubing string and form a part of the tubing string above the last acoustic repeater, the mechanical filter configured to cause an attenuation to acoustic signals propagating in the tubing string above the tree.