ICS 75.180.10 E 11 Ref.No : 65493—2018
SY
The People' s Republic of China Standard of
Petroleum and Natural Gas Industry
SY/T 10020—2018 Replace SY/T 10020—2013
Technical specifications for marine streamer
seismic data processing
Implementation date:2019 - 03 - 01
Issue date:2018 -- 10 - 29
Issued by National Energy Administration, P.R.C. SY/T 10020—2018
Contents
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Foreword
1 Scope: 2
Normative references 3 Terms and definitions 4 Preparations 4.1 Basic data collection 4.2 Check for basic data 5 Processing design and test 5.1 Processing design 5.2 Processing test 6 Technical requirements for processing 6.1 Data demultiplex or format conversion 6.2 Geometry definition 6.3 Processing polarization 6.4 Source wavelet processing 6.5 Wavelet consistency processing 6.6 Static : 6.7 Receiver motion correction 6.8 Noise attenuation for pre-stack data 6.9 Amplitude compensation 6.10 Deghost 6.11 Predictive deconvolution 6.12 Data regularization 6.13 Velocity analysis 6.14 Multiple attenuation 6.15 Normal moveout and stacks : 6.16 Poststack time migration 6.17 Prestack time migration 6.18 Prestack depth migration 6.19 Prestack migration gathers processing 6.20 Post migration processing 6.21 Filter and gain Quality control
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7.1 Quality control self check 7.2 Checking by quality control department 7.3Checking ratio 8 Processing outcome submission 8.1 Content of processing outcome 8.2 The format of outcome 8.3 Medium check of deliveries 8.4 The label of outcomes medium Auditing and acceptance
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9.1 Contents of auditing and acceptance 9.2 Quality evaluation of outcome
13 SY/T 10020—2018
Foreword
"Static” “Predictive deconvolution” “Multiple attenuation” and “Prestack migration gathers processing" has been revised (see 6.2, 6.6, 6.11, 6.14 and 6.19 of this standard as well as 6.4, 6.5, 6.8, 6.11 and 6.16 in the 2013 version) -The content related to “Final section display" has been deleted (see 6.19 in the 2013 version) ;
This specification is drafted in accordance with the rules given in the GB/T 1.1—2009 pirective for standardization-Part 1 : Structure and drafting of standards. This specification replaces the SY/T 10020—2013 Technical specification for marine seismic data processing. Compared with SY/T 10020—2013, this specification has the following main technical changes besides the editorial modifications :
-The content related to “Abbreviations" has This standard was proposed by, and within been deleted (see Chapter 3 in the 2013 the jurisdiction of, the Petroleum Geophysical
Standardization Committee.
version) ; -The part of “preparations" has been revised The standard was drafted by Geophysical Department (see Chapter 4 of this standard and Chapter 4 of -COSL, CNOOC (China) Limited-
Tianjin, Geophysical Research Institute of BGP
in the 2013 version) ; "Wavelet processing" is changed into of CNPC, Exploration & Production Institute of "Sources wavelet processing" (see 6.4 of this Sinopec Shanghai Offshore Petroleum Company.
The standard was drafted by : Zhuang Zuyin, Yang
standard and 6.3 in the 2013 version) ; "Wavelet consistency processing" is Kai, Chen Jizong, Wang Zheng, Chen Li, Fan
Baocang, Cao Zhanquan, Zhou Bin, Li Hongtu,
supplemented (see 6.5 of this standard) ; “Receiver motion correction “is supplemented Chen Maogen, Xu Qiang, Jin Mingxia, Chu (see 6.7 of this standard) ;
Rongying, Zhang Junming.
"Deghost" is supplemented (see 6.10 of this This standard replaces SY/T 10020—2013 in whole. standard) ;
The previous editions of SY/T 10020—-2013 are as
-The contents related to “Prestack time follows : migration" and “Prestack depth migration"
SY/T 10020—1998, SY/T 10020—2006 ; SY/T 10021—1998.
follow the technical requirements of SY/T 5332 (see 6.17 and 6.18 of this standard as well as This standard is published in both Chinese and
English. In the event of any discrepancy between the
6.14 and 6.15 in the 2013 version) ; The contents of "Geometry definition" texts , the Chinese version should prevail.
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Technical specifications for marine streamer
seismic data processing
1 Scope
A ghost is a short-path multiple that occurs when seismic wave travels upward and then reflected
This standard specifies the technical requirements downward at the water surface. of the design, test, technical criteria, and quality 3.3 control, etc. of marine streamer seismic data ringing
An interference wave formed by the superposition
processing. This document is applicable to offshore streamer of short-range multi-reflection wave in water seismic data processing.
layers is called ringing. 3.4 tidal correction Correct the time difference due to the sea level
2 Normative references
The following referenced documents are elevation change caused by tidal phenomena. indispensable for the application of this document. 3.5 For dated references, only the edition cited applies. receiver motion correction For undated references, the latest edition of the Correct the time difference caused by the movement referenced document (in cluding any amendments) of the receiver point relative to the shot point after
shooting during the marine streamer acquisition.
applies. SY/T 5332 Technical specifications for land seismic exploration data processing SY/T 5453Data exchange format SY/T 6839 Navigation and positioning technical specifications for towed streamers seismic survey SY/T 10015 Technical specification for towed seismic data, auxiliary data and other relevant data. streamer marine seismic data acguisition
4 Preparations 4.1 Basic data collection The basic data for seismic data processing include :
a) Auxiliary data include :
observer's logs ; navigation logs ; source wavelet ; -navigation data ; velocity data measured in water.
3 Terms and definitions
The following terms and definitions are applicable to this document. 3.1 far-field wavelet or far-field signature In marine seismic data acquisition, the wavelet received at a position far from the air gun source is called the far field wavelet. 3.2 ghost
b) Other relevant data :
Seismic acquisition operation design and operation report ; On site processing result ; -Existing geology, drilling, logging and VSP data ; -Existing processing results, processing and
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can reflect typical characteristics of underground structure, sea floor relief features and data quality to test. 5.2.2 Contents to be tested Processing test should include the following items :
interpretation report (s)
4.2 Check for basic data
4.2.1 Seismic data
Check and acquire seismic data according to acquisition lines (bundles) . The storage medium should be flawless ; all labels on storage media should be consistent with observer' s logs. 4.2.2Auxiliary data The following requirements should be complied with in the auxiliary data : a) Observer's log and navigation log must
Source wavelet treatment ; Wavelet consistent processing ; Ghost attenuation ; -Statics ; -Receiver motion correction ; -Prestack denoise ; -Amplitude compensation ; -Deconvolution ; -Multiple attenuation ; Data regularization ; Suppressing acquisition footprint ; -Velocity analysis ; -Anisotropic parameter analysis ; -Muting ; -Migration methods ; -Filter and gain control ; -Processing flow.
correspond with the requirements in SY/T 10015.
b) Tow streamer navigation data must correspond
with the requirements as described in SY/T 6839.
5 Processing design and test 5.1 Processing design The processing design report should be written based on the analysis of geology task in the survey
area, processing requirements and main focuses. 5.2.3 Testing methods The report should include the following contents :
According to the test content, perform processing with different values of single parameter ; compare and analyze test results, find the processing methodology , parameters and flow.
-Project summary ; Geology tasks and processing requirements ; -Analysis of raw data and past data ; -Focuses and difficult points in processing ; -Technical plan and flow for processing ; Testing contents and parameters ; Quality control plan ; -Progress plan ; Content of processing outcome ; Composition and responsibilities of the project system accepts ; never reduce data accuracy during team ;
Technical requirements for processing
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6.1 Data demultiplex or format conversion 6.1.1 Convert data into the format that is consistent with what seismic data processing
conversion and make sure that trace headers for processing guarantee such conversion. 6.1.2 In order to check the format conversion accuracy and quality of the raw data, no less than 1% of the total shot gathers should be displayed ;
Hardware and software resource allocation. 5.2Processing test 5.2.1 Choosing test data Within the project area, choose the seismic data that at least one common-offset section is displayed by 16 SY/T 10020—2018
each cable. 6.2 Geometry definition 6.2.1 The definition of shot points and receiver 6.4.4 Compare the amplitude spectrum, phase points should be consistent with the logs recorded in spectrum and reflected wave group characteristics of field operations.
operator or zero phase operator based on far-field source wavelet and apply it to seismic data to obtain the minimum phase or zero phase seismic data.
seismic strata before and after application of source
6.2.2 The processing grid parameter including the wavelet processing to make sure that frequency origin of the coordinates, size of bin and azimuth spectrum does not change and that phase spectrum should be defined according to field acquisition converted into either minimum or zero, the wavelet parameter and processing requirements. The characteristics of seismic strata have been improved.
positioning data and seismic records should be 6.5 Wavelet consistency processing integrated and assigned to seismic trace header. 6.2.3 Draw maps of source and receiver positions 6.5.1 When there are differences between wavelets of Geometry, fold map of CMP binning as well as of seismic data collected under different conditions different offset segments fold map.
of shooting or receiving, wavelet consistency
6.2.4 Linear moveout or other methods should be processing should be applied to the seismic data. applied to make sure that the geometry definition is 6.5.2 When there are frequency or phase
differences between the seismic data of different
correct.
6.2.5 During joint processing of multi 3D surveys, blocks during merging processing, wavelet do select reasonable common midpoint of CMP bin, consistency processing should be adopted to the bin size and azimuth to keep as even as possible for seismic data. the binning fold of the whole joint surveys.
6.5.3 The horizon segments of data with high SNR should be chosen for obtaining the shaping filter in wavelet consistency processing.
6.3 Processing polarization 6.3.1 If first break starts with negative value, it is 6.5.4 The seismic data in the blocks should be defined as normal polarity. Otherwise it is defined as basically in accordance with each other in terms of reverse polarity. Normal polarity should be used in frequency and phase characteristics after the wavelet
consistency processing. 6.6Static
data processing. 6.3.2 If no definite polarity information is provided for survey lines, the zoomed pictures of first breaks of a few shot records should be viewed 6.6.1 Source and receiver positions should be for the determination of the polarity. The reverse corrected to the sea level. polarity of data should be reversed to normal before 6.6.2 Perform delay correction of seismic source data processing.
and equipment according to observer's logs. 6.6.3 Perform time difference correction according to tidal records.
6.4 Source wavelet processing 6.4.1 Far-field source wavelet can be obtained 6.6.4 It is necessary to eliminate time difference through wavelet simulator software, original due to velocity difference when seismic waves seismic data, or near-field wavelet computation.
propagate in water.
6.4.2 Far-field wavelet should be displayed, 6.6.5 The windows for calculating residual static
should be selected at seismic horizons with better
make amplitude and phase spectra analysis. 6.4.3 Derive de-bubble operator, minimum phase quality and simple structure.
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6.10 Deghost
6.7 Receiver motion correction 6.7.1 Calculate the speed of vessel according to 6.10.1 Check trace header about cable depth the source position and shooting time, compare and gun depth whether the information is accurate and verify with the speed of vessel recorded on the before deghost.
6.10.2 Suppress the influence of frequency notch
navigation logs 6.7.2 Calculate the time-varying space moving caused by source ghost and reflecting point ghost, distance of the receiver, and carry out receiver widen frequency band of seismic data.
6.10.3 Display partial shots, CMP gathers with
motion correction. 6.7.3 Display partial representative shots and NMO, stacked section, amplitude spectrum, FK stacked section to check the effect of receiver spectrum before and after deghost to check the
effect of deghost. 6.11 Predictive deconvolution
motion correction. 6.8 Noise attenuation for pre-stack data 6.8.1 Remove abnormal shots and traces, remove 6.11.1 Use predictive deconvolution technique to
suppress surface multiples such as ringing.
or suppress abnormal amplitude. 6.8.2 Reduce random or coherent noise, during 6.11.2 The starting time of the calculation window which amplitude of the signal needs to be consistent. and the application window of deconvolution should 6.8.3 Select partial shot records and stacked be suitable to water depth. section (representing different types of noise) to 6.11.3 Display the typical and representative shots
(CMP gathers), stacked section, autocorrelation
check effect of noise reduction. 6.8.4 There should be no obvious noise within the function and amplitude spectrum before and after seismic data after noise reduction, the SNR of the deconvolution to check if reasonable deconvolution seismic data should be improved and event groups methods and their parameters are appropriate. become clearer ; there should be no obviously 6.11.4 After deconvolution, the purpose of useful seismic signal within eliminated noises.
compressing seismic wavelet, attenuation multiple, improving resolution of seismic data and highlight the characteristics of reflection wave groups should
6.9Amplitude compensation 6.9.1 Compensate the lost seismic energy during be reached. propagation to keep the energy of compensated
6.12 Data regularization 6.12.1 For narrow azimuth offshore seismic data,
seismic record balanced among shallow, middle and deep levels. 6.9.2 Eliminate the energy difference among shots display fold coverage map of bin to find out the
missing near, middle and far offset issues. For wide
and traces due to equipment factors. 6.9.3 When processing joint survey, be sure to azimuth or full azimuth seismic data, one can study keep no obvious energy difference among different coverage missing status according to near, middle surveys after the amplitude is compensated.
or far offset circumstance respectively.
6.9.4 Surface consistency amplitude compensation 6.12.2 Erase redundant traces within the same is usually needed when there is a difference between offset group and the same bin. For wide or full
azimuth data, do the work according to the groups
the shooting and the receiving conditions. 6.9.5 Display partial representative gathers, that are subdivided beforehand. stacked section, time slices, energy curve, or plan 6.12.3 Interpolate on missing trace and data to check the effect of amplitude compensation.
regularization to get a sensible distributed offset
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