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`
`PGS V. WESTERNGECO (|PR20’|4-00688)
`WESTERNGECO Exhibit 2068, pg. 1
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2068, pg. 1
`
`

`
`GEOPHYSICAL MONOGFIAPH SERIES
`
`David V. Fitterrnan, Series Editor
`William H. Dragoset ]1-., Volume Editor
`
`NUMBER '7
`
`A HANDBOOK FOR SEISMIC DATA
`
`ACQUISITION IN EXPLORATION
`
`By Brian J. Evans
`
`SOCIETY OF EXPLORATION GEOPHYSICISTS
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2068, pg. 2
`
`

`
`Evans, Brian J., 1945 -
`A handbook for seismic data acquisition in exploration / by Brian J. Evans;
`edited by William H. Dragosei. Jr‘,
`p.
`cm. M (Geophysical monograph series : no. 7)
`Includes bibliographical references and index.
`ISBN 166080-041-0 (paper : aik. paper)
`1. Seismic prospecting.
`I. Dragoset, William H.
`TN269.B.E93 1997
`622‘. 1 592———dC20
`
`il. Titie.
`
`Ill. Series.
`9641-2041
`CIP
`
`ISBN 978-0+ 3183066-3 (Series)
`ISBN 978~l~5(i080—04l‘5 (\/olunic)
`
`Society of Exploration Gcophysicisis
`P. 0, Box 702740
`Tulsix, OK 7~1»l”/0-2740
`
`1997 by Society of I3xplui'ntiui1 Gcopilysicisis
`All rights |‘t‘5L=:1‘\'t:d. This book or parts hCi‘Ci)ffli£iy not he I‘cpn)dLIcx:d in any form
`without written pcrinissioii from the publisher.
`l"ubii.<hc(l '1 997
`Rcpriuted 1997, 2005, 2007, 2009, 20 I 2
`I’riutc.d in the United Suites of America
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2068, pg. 3
`
`

`
`Chapter 5
`
`Survey Positioning
`
`5.1 Introduction
`
`Accurate positioning of a seismic line is as crucial as having the best possi-
`ble data quality. Positioning is important for three reasons: (1) many data pro-
`cessing steps require accurate relative source and receiver positions; (2) tying
`several seismic lines together requires knowledge of where they are relative
`to one another; and (3) when drilling sites are selected from seismic data they
`have to be referenced back to an actual location on the Earth's surface. Of
`
`these reasons, perhaps the last is most important: No exploration company
`wants to spend millions of dollars drilling, only to miss the target because the
`seismic data were mispositioned.
`Accurate positioning is not a trivial task, especially for marine surveys.
`Once a seismic vessel has sailed along an intended line, no permanent evi-
`dence remains behind to show where the ship actually sailed. Furthermore, at
`sea, intended shot and receiver positions cannot be identified by markers
`prior to shooting. Finally, during shooting, both the ship and the trailing
`equipment are somewhat at the mercy of the Wind, currents, and Wave action;
`the position of the shots and receivers cannot, therefore, be controlled accu-
`rately. For tl1ese reasons, positioning in marine surveys is a so-called real-time
`activity; that is, position measurements have to be made, recorded, and pro-
`Cessed as a line is shot.
`
`For land seismic surveys, positioning does not have the real-time urgency
`that it does in marine surveys. The shot and receiver positions can be marked
`on the ground either before or during the shooting of a line. Likewise, accu-
`rate marker positions can be measured leisurely at any time. Furthermore,
`land surveys have the luxury of being referenced to permanent markers, loca-
`tions that are unlikely ever to be moved. Nevertheless, accurate land position-
`ing is not simple. Survey terrains are not flat, so land positioning must
`include accurate elevation measurements, a dimension that is not so crucial
`for marine surveys. In swamps, heavily forested regions, and mountainous
`
`187
`
`PGS v. WESTERNGECO (IPR2014-00688)
`WESTERNGECO Exhibit 2068, pg. 4