Managing Subsurface Data in the Oil and Gas Sector Seismic: Seismic

By Ahmad Bin Maidinsar

The book underlines the basic workflow in managing data efficiently and professionally from data search up to data archiving. This period is also considered as the data life span within a project cycle. The book is also a good referral for undergrads in the geosciences faculties.

The nine chapters outline in detail what any subsurface data managers need to apprehend in their daily routine works.

—Chapter 1 outline the meaning of “seismic.”
—Chapter 2 outline the history of storage media.
—Chapter 3 outline the 2D and 3D seismic surveys.
—Chapter 4 outline the coordinate reference system and standard navigational data format.
—Chapter 5 outline the flow in data management.
—Chapter 6 outline the SEG-Y header analysis.
—Chapter 7 outline the standard seismic data loading.
—Chapter 8 outline the process of data cleaning.
—Chapter 9 outline what constitutes of backup, archive, and restore.

• Language: English
• Publisher: Partridge Publishing Singapore
• Release date: May 24, 2019
• ISBN: 9781543751383

Ahmad Bin Maidinsar

Ahmad Bin Maidinsar is a geophysicist turned freelance Data Management Consultant globe-trotting for the last 30 years plus serving across 14 countries in 29 sites rendering invaluable skills to clients and also leveraging their standards in handling subsurface data. Now into 2nd phase in career downloading knowledge to the new generation data managers.

Book preview

Copyright © 2019 by Ahmad Bin Maidinsar.

ISBN:      Hardcover                978-1-5437-5137-6

                Softcover                  978-1-5437-5136-9

                eBook                       978-1-5437-5138-3

All rights reserved. No part of this book may be used or reproduced by any means, graphic, electronic, or mechanical, including photocopying, recording, taping or by any information storage retrieval system without the written permission of the author except in the case of brief quotations embodied in critical articles and reviews.

Because of the dynamic nature of the Internet, any web addresses or links contained in this book may have changed since publication and may no longer be valid. The views expressed in this work are solely those of the author and do not necessarily reflect the views of the publisher, and the publisher hereby disclaims any responsibility for them.

www.partridgepublishing.com/singapore

CONTENTS

Foreword

Appreciation

Preface

I – OVERVIEW

Flow In Data Management

Further Reading

II – SEISMIC

Seismic Waves

A short introduction to seismic waves

Seismic Storage Media

Paper

Film

Sepia

Microfiche (flat sheets)

Microfilm (reels)

Floppy disks

Tapes

Optical disks

Mass Storage

Western Digital (Wd) hard drive

Latest technology

Workstation

Further Readings

III – SEISMIC SURVEYS

Survey Type

2D Survey

2D surveys line nomenclature

3D Survey

Xy/Inline/Xline for the survey area definition

Inline/Xline Range

Project/Survey Datum

Composite Lines

Further Readings

IV – COORDINATE REFERENCE SYSTEMS

So What is coordinate reference system (Crs)?

Navigation—Xy For The Line

P1/90

P6/98 (3D Bin)

World Utm Zonation Number

Defining local projection system for a project

Exercises on correct coordinates

Exercise Iv.1: Please Define The 3D Survey In Utm Z10

Exercise Iv.2: Please Define The 3D Survey In Utm Z11

Exercise Iv.3: Please Determine The Coordinates For The Corner Points A, B, C, And D For Both Zones In Figure 4-16.

Further Readings

V – THE FLOW: DATA MANAGEMENT

The eight golden rules of data management

Part I—algorithm

Data collection, gather, search

Data verification, validation, reformat, scanning, vectorizing

Data input, load, repository

Data validation, verification of the reposited data

Client, user participation

Dept head or team-lead approval

Data backups restores

Data archive, delete

Part II—details

Data collection, gather, search

Ways to collect, gather, search for data

•   Physical — media

•   Electronics — data transfer remotely

•   Forms/templates

Sources of data

•   Partners

•   Service companies

•   Operating companies

•   Old archives

•   Old media

•   Internet

•   Reports

Data verification, identification, transcription, reformat

Check the transmittals

Notes accompanying the dataset (to elaborate in detail)

Labels on the media

Checking the contents

Data input/load

Performing navigation data analysis (2d)

Create project or surveys, depending on the data

Loading 8, 16, or 32b, depending on the data

density received

Check data coverage visually

Data validation (for corrections)

User participation

3D survey information sheet

2D lines information sheet

Approval

Backup/restore

Data archive, delete

Data security

Further readings

VI – SEGY HEADER ANALYSIS

Segy Format

Ebcdic Header

Binary Header

Trace Header

Surveys

2D Seismic Survey

Line Name

Shot-Point

Trace (Cdp)–Sp Relation

•   1:1 Ratio

•   2:1 Ratio

•   5:1 Ratio

•   7:1 Ratio

Xy – Easting And Northing

Latitude And Longitude

Record Length

Sample Rates

Data Format

•   Data Storage – Format

•   Data bit – format or sample format

➢   8-bit integer

➢   16-bit integer

➢   32-bit integer

➢   64-bit integer

Polarity

Phase Mode

Seismic Elevation Datum

3D Seismic Survey

Line (Inline) – Il

Trace (Crossline) – Xl

Bin Size

Xy

Latitude and longitude

Record length

Sample rate

Data format

Polarity

Phase mode

Seismic elevation datum

Further Readings

VII – SEISMIC DATA LOADING

Set Standards In Loading Seismic

Polarity

Phase

Sample Rate

Record Length

Sample Format

3D Seismic Loading

•   Project Creation

•   Survey Definition

2D Seismic Loading

Seismic Project Creation

3D

•   Four (Corner Points)

Seismic Display

Further Readings

VIII – DATA HARMONIZATION

Objective

Data Checking

Are the surveys (2d or 3d) defined correctly with the right coordinate reference systems (crs)?

Are the overlap 3d3d seismic surveys tying to one another?

Are the overlapped 2d3d seismic surveys tying to one another?

Are the 2d2d seismic lines (vintages, i.E., Different years or different blocks or acreage) tying to one another?

Duplicated surveys

Having surveys not active for ‘ages’ i.E. For quite sometime?

Are the final seismic volumes correctly scaled?

Are there duplicated seismic volumes (8-bit dataset, 16-bit dataset, 32-bit dataset)?

Are there any unwanted generic seismic volumes generated by the users themselves e.G., Phase, frequency, spectral decomposition, and other seismic attributes that have not been deleted?

Last but not least, seismic volumes have names generated but no seismic data appear, i.E., 0 (Zero) kb

IX – BACKUP – ARCHIVE – RESTORE

Objectives

Backup

Archive

Delete

Restore

External Services

Further Readings

APPENDICES

B: Glossary

C: The Birth Of A Seismic Trace

D: Known Projection Systems

E: To Convert Decimal Degrees [Dd] To Degree, Minute, Second [Dms] Vice Versa

F: Seismic Type

G: Applied Software In Generating This Book

H: Business Model Of The 8 – Golden Rules Of Subsurface Data Management – Tetramodel

FIGURES

Figure I-1: Seismic section and a trace after undergoing processing

Figure II-1: Different modes of seismic waves detection

Figure II-2: A sinusoidal wave denoting (1) amplitude (2)

frequency (3) wavelength

Figure II-3: Example of frequencies

Figure II-4: Paper seismic section

Figure II-5: Seismic section on film—an example

Figure II-6: Seismic section on sepia—an example

Figure II-7: Microfiche

Figure II-8: Floppy disk—8, 5¼, and 3½"

Figure II-9: ½" Tape (9 – track)

Figure II-10: Cartridge types

Figure II-11: Digital Linear Tape

Figure II-12: Types of Optical disks

Figure II-13: WD 8Tb hard-drive

Figure II-14: Workstation_seismic interpretation

Figure II-15: Workstation_geological interpretation

Figure III-1: Farm-in area—BLOCK 12/15

Figure III-2: Schematic of 2D and 3D seismic survey

Figure III-3: Schematic of reflection seismic survey onshore (LHS) and offshore (RHS)

Figure III-5: Map displaying examples of 2D3D surveys

Figure III-6: 2D seismic survey operation

Figure III-7: Central Alaska—2D seismic lines visualized in 3D viewer

Figure III-8: Shot-point (SP) representation of a 2D line on a base-map with each SP registering X and Y coordinates

Figure III-9: Central Alaska—2D survey – line 58 in variable area + wiggle display mode

Figure III-10: Central Alaska 2D survey—line 58 in variable density + wiggle display mode

Figure III-11: Example of base-map displaying simplified 2D survey lines

Figure III-12: 3D Seismic survey—operation

Figure III-13: Example of 3D seismic in visualization mode

Figure III-14: Example of 3D seismic in planar mode—INLINE, XLINE, and Z

Figure III-15: 3D surveys in 3D view multiple IL, XL, and Z

Figure III-16: Bins representing the INLINE and XLINE

Figure III-17: 3D survey definition overlay map on TIMESLICE

Figure III-18: Seismic reference datum – land and sea

Figure IV-1: Base-map displaying 2D lines in XY coordinates - ©Global Data Subsurface

Figure IV-2: Basemap displaying 2D lines in XY coordinates with Latitude and Longitude overlay - ©Global Data Subsurface

Figure IV-3: The process of representing the Earth on a flat map

Figure IV-4: Schematic diagram of sphere, geoid, and ellipsoid

Figure IV-5: An ellipsoid – to represent the Earth surface

Figure IV-7: Example—UKOOA P1/90 2D navigation format

Figure IV-8: Example—UKOOA P1/90 3D navigation format

Figure IV-12: Example—UKOOA P6/98 3D Bin format

Figure