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© 2017 Chevron North Sea Limited | Company Confidential

AUV Pipeline Inspection

Damian Ling

Subsea Survey Engineer

Chevron - ETC

2© 2017 Chevron North Sea Limited | Company Confidential

Summary

Chevron and Total under their Subsea Technology Collaboration have been developing technologies to enable pipeline inspection using an Autonomous Underwater Vehicle (AUV).

The presentation will provide background to the design, developments, technical challenges, and an update of progress including the latest data from offshore trials of a commercial vehicle.

Thanks to Oceaneering Survey Services for the images and support on the project.


Project Approach

and Objectives

General Approach to Technology Development:

• Engage with the AUV Industry

• Support research and development

• Provide technology trial opportunities

• De-risk technologies for deployment

• Engagement of Business Units

Objective of the project :

• Development of a new approach to subsea pipeline inspection using AUVs


Evolution of Pipeline Inspection

Need Min. DPII Vessel

ROV

Post Processing of Data

Altitude <1m above pipeline

speed (<0.5 knot)

100 Km of Pipe Takes ~ 5 Days

CP Survey

AUV today

No Obstacle Avoidance Sonar

Navigate using As Built Data

Post Processing of Data

Altitude ~6 m above pipeline

No CP ( Technology Gap)

Innovative

Inspection AUV

Automatic Obstacle Avoidance

Sonar

Navigate using Auto-Tracking

Real-time Data Processing

Pipe defects – Features

Altitude ~2,5 m above pipeline

CP Survey (Under Development)

speed (<= 4 knot)

100 Km of Pipe Takes ~ 15h speed (<= 4 knot)

100 Km of Pipe Takes ~ 15 h

No Need for DP Vessel No Need for DP Vessel

Visual Navigation

Manual Obstacle Avoidance


Technology Challenges

We considered four main technology challenges at

project inception:

• Subsea Navigation

• Visual Inspection

• Free Span Detection

• CP Measurement


Project Status

6

2013 2014 20152012

OTC-24224-MS

Paper Issued

Issued Pipeline

Inspection

Specification

(RFQ)

Finalized Vendor

(Oceaneering)

and Project

Kick-off

Pipeline

Specification

Initiation

2016 2017

Phase 2

Design

ReviewPhase 3

Design

Review

Phase 3

Trial

Phase 1

Design

Review

Phase 1

Trial

Phase 2

Trial


Subsea Navigation

Obstacle Detection and Collision Avoidance

New nose cone designed to accommodate

horizontal and vertical beam sonar.

Obstacles are represented in a probability grid

and windows of safe travel selected in real-time.


Subsea Navigation

Robust Real-time Pipeline Following

Position and altitude control from all

available sensors.

Software computes statistical

confidence of all sensors and

determines which to use.

PIPE FOLLOWING WHEN PIPE MATCHES

AS-BUILT (GREEN IS TRACKED, WHITE IS

AS-BUILT)

ALL POTENTIAL PIPELINES ARE

DETECTED

REAL-TIME DISPLAY SHOWS

PIPELINE DETECTION FROM

MULTIPLE SENSORS

Target is +1 m cross-

track and an altitude of 1

to 2 m above pipeline.


Subsea Navigation

Real-time Feature Based Navigation

• Computer based vision algorithms to

detect and identify features

• Along –track distance re-calibrated

against feature library

• Re-acquisition if pipeline is lost

Anode

Smart Behaviours – a move towards

full autonomy:

Mission adapts as a result of condition:

• Burial status

• Free span conditions

• Pipeline crossings

• Anomaly


Visual Inspection

Digital Photography

Images are collected underexposed to allow

adjustment for variation in lighting with altitude

High Resolution Digital

Photography

Rendered into a scaled photomosaic


Visual Inspection

Digital Photography

High Resolution Digital

Photography

Rendered into a scaled photomosaic


Freespan Detection

Laser scanning

3D modeling

Significant

improvement in

resolution of cross

sectional profiles

Ability to create effective 3D

models and overlay

photography


Freespan Detection

Laser scanning

Resolution continues to increase as we lower altitude (1 – 2 m)

5m altitude(noise level ~3mm)

7m altitude(noise level <1cm))


Freespan Detection

Program also accommodates

freespan detection using side

scan sonar (with auto pipeline

tracking) offset from pipeline


Contactless CP by

AUV

CP Survey

TOTAL have been developing a

new CP approach which is being

introduced into the program

Image courtesy of TOTAL S.A Exploration and Production

Patent

Number

File

DateTitle

PCT/FR

2015/05

1193

05/0

5/15

Underwater vehicle for

inspection of a subsea

structure in a body of water

and related method


Value Proposition

• Utilize AUVs for pipeline inspection as a standard integrity

management approach

• Cost savings in comparison to ROV inspection, due to increased

speed of inspection and lower vessel cost, particularly in deeper water

• Improved quality and more manageable data with HD photographic

mosaic and 3D laser cross section model

• Data quality improvement over ROTV surveys due to navigation closer

to pipeline (closer distance and better aspect ratio) and platform

stability


Lessons Learned

What went wrong:

• Not a lot (so far)

• Estimation of time for contracting

• Need to assess turbidity in real time and adjust sensors

• Lack of data management standards for new deliverable formats

What went right:

• Detailed specification

• Offshore trials approach is powerful to validate design assumptions and simulation results

• Distinct milestones with criteria for payment

• Contracting with service provider not manufacturer

• Working as a team


Where next?

• Adoption of Pipeline Inspection AUV in our Subsea Integrity

Management Programs

• Future Field Resident AUV systems for inspection, monitoring and

light intervention resulting in reduced vessel days.


Questions?

Contact Information

Damian Ling

Chevron ETC

+44 1224 334000

[email protected]

mailto:[email protected]

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