`,Wmmmmvwmwfl
`
`m;wm~wmwwfwwgw_wwmwwwmww'
`
`
`
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2068, pg. 1
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2068, pg. 1
`
`
`
`
`
`David V. Fitterman, Series Editor
`William H. Dragoset In, Volume Editor
`
`GEOPHYSICAL MONOGRAPH SERIES
`
`NUMBER '7
`
`A HANDBOOK FOR SEISMIC DATA
`
`ACQUISITION IN EXPLORATION
`
`
`
`
`
`By Brian J. Evans
`
`
`
`SOCIETY OF EXPLORATION GEOPHYSICISTS
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2068, pg. 2
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2068, pg. 2
`
`
`
`Evans, Brian J.. 1945 ~
`A handbook for seismic data acquisition in exploration / by Brian J. Evans;
`ediied by William H. Dragoseli Jr.,
`p.
`cm. -~ (Geophysical monograph series 2 no 7)
`Includes bibliographical references and index.
`ISBN 166080-0410 (paper : alk. paper)
`1. Seismic prospecting I. Dragoset, William H.
`TN269.8.E98 1997
`62231592de20
`
`Printed in ilic United Slkllcs of America
`
`C) 1997 by 9<iciciy 01‘ Exploration (icopiiysicifis
`All rightsv ‘CX‘VCL‘L ”in; book or [warts licrciifmziy not he reprixiuccd in any form
`wiilmui written permission from ihc publisher.
`Published 1997
`Reprinted 1997, 3005, 2007, 200‘), 2012
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2068, pg. 3
`
`lll.Series.
`9642041
`ClP
`
`Ili Title.
`
`{SEN 9780931830660 (Series)
`iSBN 978~l~56080»04l~5 (Volume)
`
`Society of Exploration (Jeophysicisis
`P, O, Box 702740
`Tulsa, OK 7111704740
`
`PGS v. WESTERNGECO (IPR2014-00687)
`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 mispositionecl.
`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 these 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
`
`
`
`1E7
`
`
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2068, pg. 4
`
`PGS v. WESTERNGECO (IPR2014-00687)
`WESTERNGECO Exhibit 2068, pg. 4
`
`