			LAS FORMAT VERSION 2.0
			INFORMATION PACKAGE
			AUGUST 28, 1995
			________________________

	Enclosed are the following items:

1) A technical paper on the LAS format.(run CERTIFY to get copy)
2) An information sheet on the REFORMAT program (in README.TXT)
3) An information sheet on the CERTIFY program (in README.TXT)
4) Information on NEW FEATURES OF LAS VERSION 2.0 (in README.TXT)
5) a 3.5 inch, 1.44 megabyte floppy disk (MS/DOS, PC/DOS compatible)
 containing the following files:

	- README.TXT  = introduction to LAS information package
	- REFORMAT.EXE  = executable of the REFORMAT program
	- CERTIFY.EXE   = executable of the CERTIFY program
	- TEST01.LAS    = example file of LAS format in unwrapped mode
	- TEST02.LAS    = example file of LAS format in wrapped mode
	- TEST03.LAS    = another example of an LAS file  
	- MAIN.C        = code for REFORMAT program (ANSI standard 'C')
	- DEPTH.C       = as above
	- CURVE.C       = as above
	- REVERSE.C     = as above
	- RESAMP.C      = as above
	- UNWRAP.C      = as above
	- SCAN.C        = as above
	- CONVERT.C     = as above
	- CONVER_A.C   = as above
	- REFORMAT.MAK  = as above
	- LOCAL.H       = as above
 
						 
 _________________________________________________________________________                                      
    ________________________________________________________________________                            
			  
			
			CERTIFY (VERSION 3.50)
			MARCH 23, 1994
			____________________


	The CERTIFY program was designed to read LAS version 2.0 files 
 and establish whether all of the LAS specifications are being adhered 
 to. This program also points out where the LAS specifications are not 
 being followed

	This program issues two types of messages. One is a WARNING and the
 other is a FATAL ERROR. The WARNING is used to point out items that meet
 the LAS standard but could be improved upon to make the file more informative
 to the user. For example, if the "location" field in the Well Information
 Section is left blank the CERTIFY program will issue a WARNING. The FATAL
 ERROR message is issued on items that fail to meet the LAS specifications.
 For example if the "location" field is omitted from the Well Information
 Section, the CERTIFY program will issue a FATAL ERROR message.

	The CERTIFY program is not part of the LAS Standard. It is being
 made available to assist the user in locating and identifying the more
 commonly occurring errors. 


	    
 _____________________________________________________________________________
 _____________________________________________________________________________
 


	REFORMAT (VERSION 2.51)
	AUGUST 28, 1995
       _________________________________


	The REFORMAT program was designed to manipulate LAS formatted files
 into a form which may be more compatible with the user's needs. The REFORMAT
 program is not part of the LAS standard.

	The REFORMAT program is capable of doing the following things:

1) Extract a depth interval
	- This allows the user to build a new LAS file covering a specific
 depth interval of the input interval. It works on unwrapped data only. It
 will handle lines up to 1200 characters long.

2) Extract one or more curves
	- This allows the user to build a new LAS file containing only the
 curves specified by him. It will handle input data with lines up to 1200
 characters long. It works only on unwrapped data.

3) Reverse depth direction
	- Logs can be recorded from bottom to top or visa versa.  This routine
 reverses the depth direction. It works on unwrapped data only. It will 
 handle lines up to 1200 characters long.

4) Change depth step (i.e. depth increment)
	- The depth step refers to the depth increment. This routine works
 only on unwrapped data. It will handle lines up to 600 characters long,
 input files with up to 20,000 data lines and output files with up to 
 100,000 data lines.

5) Convert wrap to unwrap mode
	- Wrap mode refers to the mode where the depth value is on its own
 line and all of the curve data for that depth value are on the lines that
 follow (see TEST02.LAS for an example). Unwrap mode means there is only one
 line of curve data for each depth step and the depth value is the first
 value in that line. This routine converts wrapped data to the unwrapped mode
 provided that the resulting lines are not longer than 1200 characters

6) Scan for non-standard characters
	- Non ASCII or unprintable characters can cause difficulties to some
 programs. This routine allows the user to find them and delete them. 

7) Convert LAS version 1.2 to LAS version 2.0

8) Convert LAS version 2.0 to LAS version 1.2    

	The REFORMAT program was written in ANSI standard 'C' and has been
 compiled with Boreland's Turbo C++ 3.0 compiler. The author of the program 
 does not reserve any rights and does not warrant the program for any 
 specific purpose. The executable as well as the code for REFORMAT is 
 included on the enclosed floppy disk.

	Any comments should be addressed to:

		CWLS Floppy Disk Committee
		Suite 229, 640-5 Avenue S.W.
		Calgary, Alberta
		CANADA T2P 0M6

							LAS FORMAT
							INFORMATION PACKAGE
							AUGUST 28, 1995

_____________________________________________________________________________
_____________________________________________________________________________                          

					SEPTEMBER 25, 1992


	       NEW FEATURES OF LAS VERSION 2.0
		  THE FLOPPY DISK STANDARD
			FOR LOG DATA


  BY      Canadian Well Logging Society's LAS Committee

	  Case Struyk Gulf Canada Resources Ltd. (Chairman)
	  Ray Lamborn    Atlas Wireline Services
	  Glenn Gray  BPB Wireline Services
	  Jos Jonkers Computalog Ltd.
	  Gregg Peterson Great Guns Logging Services
	  George Tulle   Halliburton Logging Services
	  Gary Drebit Schlumberger of Canada


  INTRODUCTION

  The original LAS standard was introduced by the Canadian
  Well Logging Society in 1989. Its intent was to standardize
  the organization of digital log curve information for floppy
  disks. It did this very successfully and the standard is now
  popular worldwide. This new version corrects one of the
  shortcomings of the earlier version and has improved
  documentation.

  LAS version 2.0 replaces version 1.2  . Highlights of the
  changes are as follows:

     - The "WELL INFORMATION" section has been standardized
  to conform with the "CURVE INFORMATION " and the
  "PARAMETER INFORMATION" sections.

     - The documentation in regards to the locating of the
  "UNITS" in various sections has been clarified to indicate
  that they must be located directly to the right of the dot
  without any spaces.

     - An additional example has been added to the
  documentation to illustrate a method of handling time
  based data

  The CERTIFY and REFORMAT programs have been modified to
  handle LAS version 2.0 . The REFORMAT program contains an
  option that will convert LAS version 1.2 to version 2.0 .



  CHANGES TO THE WELL INFORMATION SECTION

  The "WELL INFORMATION" section has been made to conform with
  the "CURVE INFORMATION" and "PARAMETER INFORMATION"
  sections. All of these sections will now consist of lines
  laid out as follows:

       MNEM.UNITS        DATA   :DESCRIPTION OF MNEMONIC


  Where

       MNEM = mnemonic. This mnemonic can be of any length
  but must not contain any internal spaces dots or
  colons. Spaces are permitted in front of the
  mnemonic and between the end of the mnemonic and the dot.

       UNITS = units of the mnemonic (if applicable). The
  units must be located directly after the dot. There
  must be no spaces between the units and the dot. The
  units can be of any length but must not contain any colons
  or internal spaces.

       DATA  = value of, or data relating to, the mnemonic.
  This value or input can be of any length and can
  contain spaces or dots as appropriate, but must not
  contain any colons. It must be preceded by at least one
  space to demarcate it from the units and must be
  to the left of the colon.

       DESCRIPTION = description or definition of the
  mnemonic. It is always located to the right of the
  colon. Its length is limited by the total line length limit
  of 256 characters which must include a carriage return
  and a line feed.


  The changes in LAS version 2.0 effect the following lines in
  the WELL INFORMATION section:

      - The COMP line will now have the actual company name
  to the left of the colon, and the word "company" to the
  right of the colon.

       - The WELL line will have the actual well name to the
  left of the colon and the word "well" to the right of
  the colon.

       - the PROV, CNTY, STAT, CTRY lines will have the
  actual province, county, state, or country name to the
  right of the colon, and the word "province", "county",
  "state", or "country" to the right of the colon.

       - The SRVC line will have the actual service company
  name to the left of the  colon, and the words "service
  company" to the right of the colon.
 
       - The DATE line will have the actual date to the left
  of the colon and the word "date" to the right of the
  colon.

       - The UWI or API line will have the actual UWI or
  actual API location to the left of the colon and the
  words "unique well identifier" or "API location code" to the
  right of the colon


  The following is an example of a Well Information Section in
  LAS version 2.0:
			  
  ~Well Information Section
  #MNEM.UNIT          DATA        DESCRIPTION OF MNEMONIC
  #---------      -----------     ---------------------------
  STRT.M                  635.0000     :START  DEPTH
  STOP.M                  400.0000     :STOP DEPTH
  STEP.M                  -0.1250      :STEP
  NULL.                   -999.25      :NULL VALUE
  COMP.         ANY OIL COMPANY INC.   :COMPANY
  WELL.         ANY ET AL 12-34-12-34  :WELL
  FLD  .        WILDCAT                :FIELD
  LOC  .        12-34-12-34W5          :LOCATION
  PROV.         ALBERTA                :PROVINCE
  SRVC.      ANY LOGGING COMPANY INC.  :SERVICE COMPANY
  DATE.         13-DEC-86              :LOG DATE
  UWI  .        100123401234W500       :UNIQUE WELL ID



  CLARIFICATION OF THE LOCATION OF UNITS

  The original documentation was not specific enough as to the
  exact location of the units in the WELL, CURVE, and
  PARAMETER sections. The units must be located directly after
  the first dot on a line. There must be no spaces between the
  dot and the units.



  CONCLUSIONS

  A new LAS information package has been released and includes
  REFORMAT and CERTIFY programs modified for  LAS version 2.0 .
  The REFORMAT program will be capable of converting LAS
  version 1.2 to version 2.0 . This information package is
  available for $10.00 at the following address:

     Canadian Well Logging Society
     229, 640 - 5 Avenue SW
     Calgary, Alberta    T2P 0M6
     CANADA


  The LAS Committee will continue to monitor the LAS standard.
  Feedback concerning this standard is greatly appreciated and
  should be forwarded to the committee at the above address.
  



	       APPENDIX  -  EXAMPLE LAS FILES


  EXAMPLE #1 - THE LAS STANDARD IN UNWRAPPED MODE

  ~VERSION INFORMATION
  VERS.                 2.0  : CWLS LOG ASCII STANDARD -VERSION 2.0
  WRAP.                 NO   : ONE LINE PER DEPTH STEP
  ~WELL INFORMATION
  #MNEM.UNIT              DATA        DESCRIPTION OF MNEMONIC
  #----- -----          ----------    --------------------------
  STRT .M           1670.0000          :START DEPTH
  STOP .M           1669.7500          :STOP DEPTH
  STEP .M           -0.1250            :STEP
  NULL .            -999.25            :NULL VALUE
  COMP .    ANY OIL COMPANY INC.       :COMPANY
  WELL .    ANY ET AL 12-34-12-34      :WELL
  FLD  .    WILDCAT                    :FIELD
  LOC  .    12-34-12-34W5              :LOCATION
  PROV .    ALBERTA                    :PROVINCE
  SRVC .    ANY LOGGING COMPANY INC.   :SERVICE COMPANY
  DATE .    13-DEC-86                  :LOG DATE
  UWI  .    100123401234W500           :UNIQUE WELL ID
  ~CURVE INFORMATION
  #MNEM.UNIT          API CODES      CURVE DESCRIPTION
  #-----------      ---------       -------------------------
  DEPT .M                           :  1  DEPTH
  DT   .US/M         60 520 32 00   :  2  SONIC TRANSIT TIME
  RHOB .K/M3         45 350 01 00   :  3  BULK DENSITY
  NPHI .V/V          42 890 00 00   :  4   NEUTRON POROSITY
  SFLU .OHMM         07 220 04 00   :  5  RXORESISTIVITY
  SFLA .OHMM         07 222 01 00   :  6  SHALLOW RESISTIVITY
  ILM  .OHMM         07 120 44 00   :  7  MEDIUM RESISTIVITY
  ILD  .OHMM         07 120 46 00   :  8  DEEP RESISTIVITY
  ~PARAMETER INFORMATION
  #MNEM.UNIT          VALUE            DESCRIPTION
  #---------       ---------          ----------------------
  MUD  .            GEL CHEM            :   MUD TYPE
  BHT  .DEGC        35.5000             :   BOTTOM HOLE TEMPERATURE
  BS   .MM          200.0000            :   BIT SIZE
  FD   .K/M3        1000.0000           :   FLUID DENSITY
  MATR .            SAND                :   NEUTRON MATRIX
  MDEN .            2710.0000           :   LOGGING MATRIX DENSITY
  RMF  .OHMM        0.2160              :   MUD FILTRATE RESISTIVITY
  DFD  .K/M3        1525.0000           :   DRILL FLUID DENSITY
  ~OTHER
     Note: The logging tools became stuck at 625 metres
     causing the data between 625 metres and 615 metres to be
     invalid.
  ~A  DEPTH    DT    RHOB       NPHI     SFLU    SFLA     ILM      ILD
  1670.000  123.450 2550.000   0.450  123.450  123.450  110.200  105.600
  1669.875  123.450 2550.000   0.450  123.450  123.450  110.200  105.600
  1669.750  123.450 2550.000   0.450  123.450  123.450  110.200  105.600





  EXAMPLE #2 - ILLUSTRATING THE  LAS STANDARD WITH MINIMUM HEADER
	       REQUIREMENTS IN UNWRAPPED MODE.
			      
  ~V
  VERS .               2.0 :   CWLS log ASCII Standard -VERSION 2.0
  WRAP.                NO  :   One line per depth step
  ~W
  STRT.M             635.0000          :START DEPTH
  STOP.M             634.5000          :STOP DEPTH
  STEP.M            -0.1250            :STEP
  NULL.             -999.25            :NULL VALUE
  COMP.     ANY OIL COMPANY INC.       :COMPANY
  WELL.     ANY ET AL 12-34-12-34      :WELL
  FLD .     WILDCAT                    :FIELD
  LOC .     12-34-12-34W5              :LOCATION
  PROV.     ALBERTA                    :PROVINCE
  SRVC.     ANY LOGGING COMPANY INC.   :SERVICE COMPANY
  DATE .    13-DEC-86                  :LOG DATE
  UWI .     100123401234W500           :UNIQUE WELL ID
  ~C
  DEPT .M                       :   DEPTH
  RHOB .K/M3                    :   BULK DENSITY
  NPHI .VOL/VOL                 :   NEUTRON POROSITY -SANDSTONE
  MSFL .OHMM                    :   Rxo RESISTIVITY
  SFLA .OHMM                    :   SHALLOW RESISTIVITY
  ILM  .OHMM                    :   MEDIUM RESISTIVITY
  ILD  .OHMM                    :   DEEP RESISTIVITY
  SP   .MV                      :   SPONTANEOUS POTENTIAL
  ~A
  635.0000  2256.0000  0.4033  22.0781  22.0781  20.3438  3.6660 123.4
  634.8750  2256.0000  0.4033  22.0781  22.0781  20.3438  3.6660 123.4
  634.7500  2256.0000  0.4033  22.0781  22.0781  20.3438  3.6660 123.4
  634.6250  2256.0000  0.4033  22.0781  22.0781  20.3438  3.6660 123.4
  634.5000  2256.0000  0.4033  22.0781  22.0781  20.3438  3.6660 123.4




	    EXAMPLE #3 - ILLUSTRATING THE WRAPPED
		 VERSION OF THE LAS STANDARD

  ~VERSION INFORMATION
  VERS  .                 2.0  :   CWLS log ASCII Standard -VERSION 2.0
  WRAP.                   YES  :   Multiple lines per depth step
  ~WELL INFORMATION
  #MNEM.UNIT           DATA          DESCRIPTION OF MNEMONIC
  #----- -----        -------     ---------------------------
  STRT .M           910.0000           :START DEPTH
  STOP .M           909.5000           :STOP DEPTH
  STEP .M           -0.1250            :STEP
  NULL .            -999.25            :NULL VALUE
  COMP .    ANY OIL COMPANY INC.       :COMPANY
  WELL .    ANY ET AL 12-34-12-34      :WELL
  FLD  .    WILDCAT                    :FIELD
  LOC  .    12-34-12-34W5              :LOCATION
  PROV .    ALBERTA                    :PROVINCE
  SRVC .    ANY LOGGING COMPANY INC.   :SERVICE COMPANY
  SON  .    142085                     :SERVICE ORDER NUMBER
  DATE .    13-DEC-86                  :LOG DATE
  UWI  .    100123401234W500           :UNIQUE WELL ID
  ~CURVE INFORMATION
  #MNEM.UNIT                     CURVE DESCRIPTION
  #---------                   --------------------
  DEPT .M                      :    Depth
  DT   .US/M                   :  1 Sonic Travel Time
  RHOB .K/M                    :  2 Density-Bulk Density
  NPHI .V/V                    :  3 Porosity -Neutron
  RX0  .OHMM                   :  4 Resistivity -Rxo
  RESS .OHMM                   :  5 Resistivity -Shallow
  RESM .OHMM                   :  6 Resistivity -Medium
  RESD .OHMM                   :  7 Resistivity -Deep
  SP   .MV                     :  8 Spon.Potential
  GR   .GAPI                   :  9 Gamma Ray
  CALI .MM                     : 10 Caliper
  DRHO .K/M3                   : 11 Delta-Rho
  EATT .DBM                    : 12 EPT Attenuation
  TPL  .NS/M                   : 13 TP -EPT
  PEF  .                       : 14 Photoelectric Factor
  FFI  .V/V                    : 15 Porosity -NML FFI
  DCAL .MM                     : 16 Caliper-Differential
  RHGF .K/M3                   : 17 Density-Formation
  RHGA .K/M3                   : 18 Density-Apparent
  SPBL .MV                     : 19 Baselined SP
  GRC  .GAPI                   : 20 Gamma Ray BHC
  PHIA .V/V                    : 21 Porosity -Apparent
  PHID .V/V                    : 22 Porosity -Density
  PHIE .V/V                    : 23 Porosity -Effective
  PHIN .V/V                    : 24 Porosity -Neut BHC
  PHIC .V/V                    : 25 Porosity -Total HCC
  R0   .OHMM                   : 26 Ro
  RWA  .OHMM                   : 27 Rfa
  SW   .                       : 28 Sw -Effective
  MSI  .                       : 29 Sh Idx -Min
  BVW  .                       : 30 BVW
  FGAS .                       : 31 Flag -Gas Index
  PIDX .                       : 32 Prod Idx
  FBH  .                       : 33 Flag -Bad Hole
  FHCC .                       : 34 Flag -HC Correction
  LSWB .                       : 35 Flag -Limit SWB
  ~A Log data section
  910.000000
  -999.2500 2692.7075     0.3140    19.4086   19.4086   13.1709  12.2681
    -1.5011   96.5306   204.7177    30.5822 -999.2500 -999.2500  3.2515
  -999.2500    4.7177  3025.0264  3025.0264   -1.5010   93.1378  0.1641
     0.0101    0.1641     0.3140     0.1641   11.1397    0.3304  0.9529
     0.0000    0.1564     0.0000    11.1397    0.0000    0.0000  0.0000  
  909.875000
  -999.2500 2712.6460     0.2886    23.3987   23.3987   13.6129  12.4744
    -1.4720   90.2803   203.1093    18.7566 -999.2500 -999.2500  3.7058
  -999.2500    3.1093  3004.6050  3004.6050   -1.4720   86.9078  0.1456
    -0.0015    0.1456     0.2886     0.1456   14.1428    0.2646  1.0000
     0.0000    0.1456     0.0000    14.1428    0.0000    0.0000  0.0000
  909.750000
  -999.2500 2692.8137     0.2730    22.5909   22.5909   13.6821  12.6146
    -1.4804   89.8492   201.9287     3.1551 -999.2500 -999.2500  4.3124
  -999.2500    1.9287  2976.4451  2976.4451   -1.4804   86.3465  0.1435
     0.0101    0.1435     0.2730     0.1435   14.5674    0.2598  1.0000
     0.0000    0.1435     0.0000    14.5674    0.0000    0.0000  0.0000
  909.625000
  -999.2500 2644.3650     0.2765    18.4831   18.4831   13.4159  12.6900
    -1.5010   93.3999   201.5826    -6.5861 -999.2500 -999.2500  4.3822
  -999.2500    1.5826  2955.3528  2955.3528   -1.5010   89.7142  0.1590
     0.0384    0.1590     0.2765     0.1590   11.8600    0.3210  0.9667
     0.0000    0.1538     0.0000    11.8600    0.0000    0.0000  0.0000
  909.500000
  -999.2500 2586.2822     0.2996    13.9187   13.9187   12.9195  12.7016
    -1.4916   98.1214   201.7126    -4.5574 -999.2500 -999.2500  3.5967
  -999.2500    1.7126  2953.5940  2953.5940   -1.4916   94.2670  0.1880
     0.0723    0.1880     0.2996     0.1880    8.4863    0.4490  0.8174
     0.0000    0.1537     0.0000     8.4863    0.0000    0.0000  0.0000




	  EXAMPLE # 4  LAS FILE FOR TIME BASED DATA

  ~VERSION INFORMATION
  VERS.                 2.0 :   CWLS LOG ASCII STANDARD -VERSION 2.0
  WRAP.                  NO :   ONE LINE PER TIME STEP
  #
  ~WELL INFORMATION
  STRT .S           0.0000             :START TIME
  STOP .S           1.5000             :STOP TIME
  STEP .S           0.3000             :STEP
  NULL .            -999.25            :NULL VALUE
  COMP .    ANY OIL COMPANY INC.       :COMPANY
  WELL .    ANY ET AL 12-34-12-34      :WELL
  FLD  .    WILDCAT                    :FIELD
  LOC  .    12-34-12-34W5              :LOCATION
  PROV .    ALBERTA                    :PROVINCE
  SRVC .    ANY LOGGING COMPANY INC.   :SERVICE COMPANY
  DATE .    13-DEC-86                  :LOG DATE
  UWI  .    100123401234W500           :UNIQUE WELL ID
  #
  ~CURVE INFORMATION
  ETIM.S                      :  1 ELAPSED TIME
  BFR1.OHMM                   :  2  SINGLE PROBE 1 RESISTIVITY
  BSG1.PSIG                   :  3  SINGLE PROBE 1 STRAIN GAUGE PRESSURE
  #
  ~PARAMETER INFORMATION
  MRT  .DEGC          67.0             : BOTTOM HOLE TEMPERATURE
  GDEPT  .M           3456.5           : GAUGE DEPTH
  DFD  .KG/M3         1000.0           : MUD WEIGHT
  #
  ~A
  0.0000              0.2125         16564.1445
  0.3000              0.2125         16564.1445
  0.6000              0.2125         16564.2421
  0.9000              0.2125         16564.0434
  1.2000              0.2125         16564.0430
  1.5000              0.2125         16564.0435


