las-java is a Java library for parsing .Las file (Geophysical well log files).

Currently supports only version 2.0 of LAS Specification. For more information about this format, see the Canadian Well Logging Society product page.

How to use

Installing

Download .jar and add jar file as a Module to your Java project:

Download from https://github.com/engage-so/engage-java/releases/tag/v1.0.0

On Intellij IDEA: File -> Project Structure -> Modules -> Dependencies Tab -> Add -> JARs or Directories -> Attach jar

On Netbeans: Project properties -> Libraries -> Compile -> ADD JAR/folder -> Add Jar

Usage

create a LasJava object

las = new LasJava("./src/test/java/com/laslibs/sample/example1.las", true);

You can also pass LAS file contents directly to constructor

String lasString = 
      "~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
      "#----- -----            ----------               -------------------------
      "STRT    .M              1670.0000                :START DEPTH.........
// add false to constructor options
      
LasJava myLas = new LasJava(lasString, false);

Read data

Use las.getData() to get a 2-dimensional array containing the readings of each log, Or las.getDataStripped() to get the same as above but with all rows containing null values stripped off

LasJava myLas = new LasJava(lasString, false);

String[][] data = las.getData();
System.out.println(Arrays.deepToString(value));

/**
   [[2650.0, 177.825, -999.25, -999.25],
    [2650.5, 182.5, -999.25,-999.25],
    [2651.0,180.162, -999.25, -999.25],
    [2651.5, 177.825, -999.25, -999.25],
    [2652.0, 177.825, -999.25, -999.25] ...]
  */

String[][] dataStripped = las.getDataStripped();
System.out.println(Arrays.deepToString(value));

/**
 [[2657.5, 212.002, 0.16665, 1951.74597],
 [2658.0, 201.44, 0.1966, 1788.50696],
 [2658.5, 204.314, 0.21004, 1723.21204],
 [2659.0, 212.075, 0.22888, 1638.328],
 [2659.5, 243.536, 0.22439, 1657.91699]...]
 */

• Get the log headers

      // ...
      String[] headers = las.getHeader();
      System.out.println(headers);
      // ['DEPTH', 'GR', 'NPHI', 'RHOB']
     // ...

• Get the log headers descriptions

      //...
      String[] headers = las.getHeaderAndDescr();
      System.out.println(headers);
      // {DEPTH: 'DEPTH', GR: 'Gamma Ray', NPHI: 'Neutron Porosity', RHOB: 'Bulk density'}
      // ...

• Get a particular column, say Gamma Ray log

      // ...
      String[] column = las.getColumn('GR');
      System.out.println(column);
      // [-999.25, -999.25, -999.25, -999.25, -999.25, 122.03, 123.14, ...]
      // ...

      // ...
      // get column with null values stripped
      String[] column = las.getColumnStripped('GR');
      System.out.println(column);
      // [61.61, 59.99, 54.02, 50.87, 54.68, 64.39, 77.96, ...]
      // ...

  Note this returns the column, after all the data has been stripped off their null values, which means that valid data in a particular column would be stripped off if there is another column that has a null value

• Get the Well Parameters

  Presents a way of accessing the details of individual well parameters.

  The details include the following:

    1. description - Description/ Full name of the well parameter
    2. units - Its unit measurements
    3. value - Value
  

    // ...
    Map<String, Map<String, String>> well = las.getWellParams()
    String start = well.get("STRT").get("value") // 1670.0
    String stop = well.get("STOP").get("value") // 1669.75
    String null_value = well.get("NULL").get("value") //  -999.25
    // Any other well parameter present in the file, can be gotten with the same syntax above
    // ...

• Get the Curve Parameters

  Presents a way of accessing the details of individual log columns.

  The details include the following:

    1. description - Description/ Full name of the log column
    2. units - Unit of the log column measurements
    3. value - API value of the log column
  

    // ...
    Map<String, Map<String, String>> well = las.getCurveParams()
    String NPHI = curve.get("NPHI").get("description") // 'Neutron Porosity'
    String RHOB = curve.get("RHOB").get("description") // 'Bulk density'
    // This is the same for all log column present in the file
    // ...

• Get the Parameters of the well

  The details include the following:

    1. description - Description/ Full name of the log column
    2. units - Unit of the log column measurements
    3. value - API value of the log column
  

    // ...
    Map<String, Map<String, String>> well = las.getWellParams(); // 'BOTTOM HOLE TEMPERATURE'
    String BHT = param.get("BHT").get("description") // 'BOTTOM HOLE TEMPERATURE'
    String BHTValaue = param.get("BHT").get("value") // 35.5
    String BHTUnits = param.get("BHT").get("units") // 'DEGC'
    // This is the same for all well parameters present in the file
    // ...

• Get the number of rows and columns

      // ...
      int numRows =  las.rowCount() // 4
      int numColumns =  las.columnCount() // 30
      // ...

• Get the version and wrap

      // ...
      double version = las.getVersion() // '2.0'
      boolean wrap = las.getWrap() // true
      // ...

• Get other information

      // ...
      String other = las.other()
      System.out.println(other)
      // Note: The logging tools became stuck at 625 metres causing the data between 625 metres and 615 metres to be invalid.
      // ...

• Export to CSV

      //...
      las.toCsv("mainTest")
      // Written successfully
      //...

  result.csv

  DEPT	RHOB	GR	NPHI
  0.5	-999.25	-999.25	-0.08
  1.0	-999.25	-999.25	-0.08
  1.5	-999.25	-999.25	-0.04
  ...	...	...	...
  1.3	-999.25	-999.25	-0.08

  Or get the version of csv with null values stripped

      // ...
      las.toCsvStripped('clean')
      // Written successfully
      // ...

  clean.csv

  DEPT	RHOB	GR	NPHI
  80.5	2.771	18.6	-6.08
  81.0	2.761	17.4	-6.0
  81.5	2.752	16.4	-5.96
  ...	...	...	...
  80.5	2.762	16.2	-5.06

• Support

  las-java is an MIT-licensed open source project. You can help it grow by becoming a sponsor/supporter.