1.0 PURPOSE

This standard initially applies to digital represntations This standard initially applies to digital representations of well logs or well reports and associated enclosures produced either as a native file or by scanning. The standard will subsequently be updated as the requirements to submit other data and media types are identified.

2.0 DEFINITIONS

2.1           IMAGE FILES

2.2           HARDCOPY DOCUMENTS

Include paper and film documents that may be read by the human eye without the need of any technology.

2.3           DIGITAL DATA

Well log curves in LIS, DLIS and other industry formats in which data is held as discrete digital values. Data in these formats is not included in the scope of this standard.  CDA will accept image files according to the specifications detailed below in section 2 and will also accept hardcopy documents. Hardcopy documents will be scanned upon receipt according to the scanning specifications detailed below (Section 1). Hardcopy and image files are deemed to be identical and where both exist only the image version should be submitted to CDA.  CDA aims to move towards digital only submission of data and to eliminate the need for hardcopy scanning.

3.0 SCANNING

All scanning undertaken by CDA will be either to PDF or TIFF format

3.1     PURPOSE OF SCANNING

• To provide an archive
• To realise cost reduction by reducing the number of versions of hard copy
• To improve accessibility to the data

3.2     STANDARD OBJECTIVES

The objective of the standard is to comply with the baseline TIFF specification. TIFF extensions are not included within the standard as it cannot be guaranteed that these will be implemented within a particular product. TIFF specification revision 6 has been used as the base for this standard.

3.3     BLACK AND WHITE ITEMS

• Header tags as per TIFF standard
• Resolution / 200 dpi (composite logs at 300 dpi)
• Thresholds
• Compression CCITT group IV
• Tiling No
• Grey scale Bilevel
• File formats TIFF

3.4     GREY SCALE ITEMS

• Header tags as per TIFF standard
• Resolution / 200 dpi
• Thresholds
• Compression None
• Tiling No
• Grey scale 256 levels of grey
• File formats LZW Compressed TIFF

3.5     COLOUR ITEMS

• Header tags as per TIFF standard
• Resolution / 200 dpi
• Thresholds
• Compression None
• Tiling No
• Palette colour 256 colours
• File formats LZW Compressed TIFF

3.7     GENERAL COMMENTS ON SCANNING

Every effort should be made during the scanning process to maximise quality of the image and minimise file size. Colour scanning should only be applied to individual pages where the use of colour is fundamental to the interpretation of the report or log. A useable file size should be produced. If an image over 50MB is produced this must be split prior to submission.

4.0 IMAGE FORMATS

DEFINITIONS

4.2          MetafileCGM

Is a proprietary Baker Atlas Vector format for Image files [that conforms with the CGM format standard].

4.3          PDF (Portable Document Format)

Is a proprietary Raster format of Adobe Systems Incorporated.

4.4          PDS (Picture Description System)

Is a proprietary Schlumberger graphics metafile format used to describe, store and transport well logs. PDS is a Vector format

4.5          TIFF (Tagged Image File Format)

Is a Raster file format that is designed to promote the interchange of image data and originated in 1986 when vendors worked together to create a standard file format for images used in desktop publishing. CDA’s standard for TIFF is set out in Section 1.

4.6          VECTOR FORMATS

Describe images in high level geometric terms such as lines, circles, arcs, ellipses, polygons, text strings and cell arrays. They are distinct from Raster files which represent images as a series of pixels.

5.0 WELL LOGS

5.1     INPUT STANDARDS

It is preferred that Image files for well logs should be submitted to CDA in an approved Vector format such as CGM and PDS.  Where no Vector format version is available, CDA will accept well log image files in the TIFF format stipulated in Section 1.  PDF format logs may be accepted in instances where there is no alternative recognised Vector format file or scannable hardcopy version available. PDF versions of logs must be continuous feed with no page breaks.  Where no Image file exists for a well log, CDA will create a TIFF image file (to the standard set out in Section 1) from a Hardcopy version through the document scanning process.

5.2     STORAGE STANDARDS

CDA will store Image files for well logs in the format in which they are originally input (i.e. in CGM, PDS, PDF or TIFF).

5.3     OUTPUT STANDARDS

Image files for well logs will be available as output in the same format in which they were originally input to CDA.

6.0 WELL REPORTS

6.1     INPUT STANDARDS

Image files for well reports should be submitted to CDA in either PDF or TIFF format.  The version of PDF with image searchable text is preferred but the standard PDF version is also accepted by CDA.  Where no Image file exists for a well report, CDA will create a TIFF image file (to the standard set out in Section 1) through the Hardcopy scanning process.  Word and Excel files should be converted to PDF before submission.  If this is not possible for Excel files the file should be saved as a .csv text file before submission.

6.2     STORAGE STANDARDS

CDA will store Image files for well reports in the format in which they are input (i.e. in PDF or TIFF).

6.3     OUTPUT STANDARDS

Image files for well reports will be available as output in the same format in which they were input to CDA.

Revised: 28 July 2006