The following supported file formats are defined below:
The following is a truncated example of an IHS formatted ASCII file. One header card is required. It must contain an identifier string, the first depth, the last depth, the depth increment, and the units. If the units are missing, GeoSyn prompts you to select them. GeoSyn currently only supports single log files.
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Test Well 204.0 1463.8 0.2000 M SONIC |
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204.0 364.76 361.88 360.86 363.92 369.15 374.39 379.62 382.22 381.31 379.54 10 206.0 377.76 375.93 373.71 371.16 368.62 366.78 367.17 369.08 370.99 372.90 10 208.0 374.99 377.58 380.46 383.34 386.22 389.10 393.41 399.86 407.72 414.99 10 210.0 415.48 410.51 405.55 400.58 396.70 394.32 392.52 390.89 389.36 388.62 10 212.0 388.59 388.57 388.54 388.51 388.49 388.41 388.18 387.87 387.56 387.25 10 ... 1454.0 161.02 158.81 156.61 155.50 155.54 155.64 155.74 155.68 155.45 155.21 10 1456.0 155.12 155.99 157.66 159.33 161.00 162.67 164.10 165.21 166.24 167.27 10 1458.0 168.30 169.37 170.59 171.92 173.26 174.60 176.01 174.26 168.08 162.26 10 1460.0 161.92 165.63 169.59 173.82 178.37 183.10 187.84 182.83 168.57 160.55 10 1462.0 161.62 166.09 170.56 174.93 179.11 183.22 187.65 190.07 190.10 190.09 10 #TOPS# 5 Top1 258.0 Top2 348.0 Top3 481.0 Top4 599.5 Top5 684.0 KB 900.9 No special end of file characters are required. |
After you have created and saved a new synthetic, the synthetic is saved to disk as a binary file with the optional extension .syn. This file contains all the information necessary to re-create the state of the synthetic as well as the raw log data.
The Canadian Well Logging Society's Floppy Disk Committee has designed a standard format for log data on floppy disks. It is known as the LAS format (Log ASCII Standard). LAS consists of files written in ASCII and containing minimal header information. The LAS format has evolved over the years. GeoSyn currently supports the import of two versions, 2.0 and 1.2.
GeoSyn will read an attached tops file, although strictly speaking tops are not included in the official LAS format. Two styles of tops formats are supported in Version 2.0, and one format is supported in Version 1.2.
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Truncated Example of LAS Version 2.0 |
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~VERSION INFORMATIONVERS. 2.00:CWLS LOG ASCII STANDARD - VERSION 2.00WRAP. NO :One Line per depth step#~WELL INFORMATION#MNEM.UNIT DATA DESCRIPTION#--------- ----------------------------------- ------------------------------STRT.M 249.7836 :START DEPTHSTOP.M 1254.2520 :STOP DEPTHSTEP.M 0.1520 :STEP LENGTHNULL. -999.2500 :NULL VALUECOMP. AnyCompany OIL & GAS LIMITED :COMPANYWELL. AnyCompany etal AnyWhere :WELLLOC . AnyWhere :LOCATION#~CURVE INFORMATION#MNEM.UNIT DATA DESCRIPTION#--------- ----------------------------------- ------------------------------DEPT.M :1 DepthDT .US/M 7 520 80 00 :2 Sonic Travel TimeRHOB.G/C3 31 350 02 00 :3 Bulk Density#~PARAMETER INFORMATION#MNEM.UNIT DATA DESCRIPTION#--------- ----------------------------------- ------------------------------EKB .M 300.0000 :Kelly bushing#~t 7 Tops //or ~T 7 TopsT0 647.98T1 800.89T2 1011.86Wabamun 1132.40Ireton 1536.64Slave Point 1812.01Pre Cambrian 1841.80#~A DEPT DT RHOB249.7836 410.825 1819.972249.9356 410.752 1791.029250.0876 410.679 1802.005250.2396 410.607 1869.852250.3916 410.534 1908.247250.5436 410.461 1958.225250.6956 410.388 1987.873250.8476 410.316 2014.986250.9996 410.249 2022.811...1253.4396 169.758 2730.6461253.5916 169.758 2730.6461253.7436 169.758 2730.6461253.8956 169.758 2730.6461254.0476 169.758 2730.6461254.1996 58.382 939.106No special end of file characters are required.**alternate tops format~Formation Tops Information#TOPS NAME . DEPTH:BR . 7221.0410:WPBI . 8034.6790:COLO . 8539.9220:CARD . 9553.6900:CARD . 9671.7980:L CA . 9743.9760:BKST . 9799.7500: |
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Truncated Example of LAS Version 1.2 |
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~Version : LASOUT vs 1.20VERS. 1.20: CWLS Log ASCII Standard -VERSION 1.20WRAP. NO: One line per depth step~Well Information Block#MNEM.UNIT Data Type Information#----.---- ------------: ------------------------------STRT.M 250.0000: Start DepthSTOP.M 2413.0000: End DepthSTEP.M .2000: Depth IncrementNULL. -999.25:COMP. COMPANY:WELL. WELL: Dog Patch LAKE 5-4FLD . FIELD: Dog PatchLOC . LOCATION: 10-10-99-1w6PROV. PROVINCE: ALBERTASRVC. SERVICE COMPANY: FlyByNight LoggersDATE. LOG DATE: 1889/12/29UWI . UNIQUE WELL ID: 0101010101010~Parameter Information Block#MNEM.UNIT Value Description#----.---- ------------: ------------------------------BHT .DEGF .0000: Bottom Hole TemperatureBS .MM .0000: Bit SizeDFD .0000: Mud Weight (Density)DFV .0000: Mud ViscosityDFL . .0000: Mud Fluid LossDFPH .0000: Mud pHRM .OHMM .0000: Mud ResistivityRMT .DEGF .0000: Mud Resistivity TemperatureRMFS.OHMM .0000: Mud Filtrate ResistivityRMFT.DEGF .0000: RMF TemperatureRMC .OHMM .0000: Mud Cake ResistivityRMCT.DEGF .0000: RMC TemperatureEKB .M 987.5000: Elevation Kelly BushingEGL .M 982.3000: Elevation Ground Level~Curve Information Block#MNEM.UNIT API CODE Curve Description#----.---- ------------: ------------------------DEPT.M : 1 DEPTHDT .USM 60 520 0 1: 2RHOB.KM3 42 350 1 1: 3~A Depth DT RHOB250.0000 376.4800 1922.6000250.2000 345.2000 1998.4000250.4000 313.9200 2363.4000250.6000 282.6400 2512.2000250.8000 254.4400 2463.2000251.0000 275.8800 2392.0000...2411.2000 -999.2500 2715.90002411.4000 -999.2500 2713.90002411.6000 -999.2500 2712.40002411.8000 -999.2500 2707.20002412.0000 -999.2500 2691.00002412.2000 -999.2500 2674.80002412.4000 -999.2500 2658.60002412.6000 -999.2500 2640.70002412.8000 -999.2500 2683.40002413.0000 -999.2500 2730.9000No special end of file characters are required. |
GeoSyn can export integrated time data (traces, wavelets, wells, rocs, etc.) in SEGY format. The format specification discussed here is a derivative of the SEGY 9-track standard. Because there is no official MS DOS standard, some liberties have been taken with respect to the original specifications. For a discussion of the 9-track SEGY format, refer to "Recommended Standards for Digital Tape Formats" K.M. Barry, D.A. Cavers, C.W. Kneale: Geophysics, Vol. 40 No. 2, p. 344-352.
A SEGY file consists of three sections or blocks:
The first 3600 bytes of the file is the File Identification Header and consists of a 3200-byte ASCII card image block followed by a 400-byte binary block. The 3200-byte ASCII section represents a deviation from the 9-track SEGY standard, which specifies that this section be in EBCDIC format. Both are text formats, but use of the ASCII format enables a user to read this portion of the SEGY file in any PC-based text editor. This deviation from the standard has no detrimental effects because most programs rely on the binary data for hard information.
The ASCII section consists of 40 lines of 80 characters each. Each line starts with a C and the line number. The following is an abridged example of the 3200-byte ASCII header for a typical GeoSyn SEGY file and describes the well name, sample rate, data type, and byte order. This same information is encoded in the 400-byte binary section.
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C1 GeoSyn Synthetic Seismogram C2 ABC OIL AND GAS 11-11-11-11W1 C3 Date: 11:35 AM Fri Dec 01, 1995� C4 Sample Rate: 2.00 (ms) C5 Data Type: Integer(2 byte) C6 Byte Swap: Yes C7 ..... C36 C37 C38 C39 C40 |
The 400-byte binary file header follows the ASCII file header and is situated on bytes 3201 to 3600. GeoSyn does not require or make use of most of the space.
The following bytes are used:
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3213 to 3214 Number of byte traces per record =1 3217 to 3218 Sample interval in microseconds 3221 to 3222 Number of samples per data trace 3225 to 3226 Data sample format code (will be either 1 or 3) 1=floating point (4bytes) 2=fixed point (4 bytes) 3=fixed point (2 bytes) 4=fixed point with gain code (4 bytes) 3261 to 3262 Total number of traces per line =1 3269 to 3270 Start time of data trace (can be negative in the case of a wavelet) |
The trace header is a 240-byte binary section that precedes each section of trace data. GeoSyn only writes one data curve, so there is one trace header in the file. The trace header occupies bytes 3601 to 3840. The bytes used by GeoSyn are tabulated below. Note that some values are 4 bytes long instead of 2-byte integer.
The following bytes are used:
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3601 to 3604 Trace Number. 3629 to 3630 Trace identification code 1=seismic data, 2=dead trace. 3715 to 3716 Number of samples. 3717 to 3718 Sample interval in microseconds. |
Trace data is stored in binary format and follows the 240-byte trace header. The binary data may be stored in one of two formats, 16-bit integer or IEEE floating point. The 16-bit integer format requires 2 bytes per amplitude value, whereas the floating point format requires 4 bytes.
The data area follows the trace header and consists of a number of 2- or 4-byte numbers representing the amplitude data of the trace or wavelet. Note that the number of samples in this record will exceed the number of samples in the synthetic if a trace is being saved, because the roll out portion of the trace below the bottom of the log is included. The number of extra samples will equal the length of the trace plus half the length of the wavelet operator.