Changes

==Features==

==Features==

Log analysis packages usually store data in a depth-oriented database. This directly associates a well's scientific data (including wireline traces, core data, tops, and test intervals) with the specific depths of their occurrence. Depending on the LAP used, database depth values may change (1) by a constant increment (usually based on the smallest common sampling increment) or (2) by varying increments (based on each trace's unique sampling nature).

Log analysis packages usually store data in a depth-oriented database. This directly associates a well's scientific data (including wireline traces, [[Overview of routine core analysis|core data]], tops, and test intervals) with the specific depths of their occurrence. Depending on the LAP used, database depth values may change (1) by a constant increment (usually based on the smallest common sampling increment) or (2) by varying increments (based on each trace's unique sampling nature).

To use this data successfully for display and calculations, the user needs to learn the purpose and method of operation for each of the seven basic LAP features. They are

To use this data successfully for display and calculations, the user needs to learn the purpose and method of operation for each of the seven basic LAP features. They are

==Data input==

==Data input==

''Digital data'' are created by writing values into a file in numerical form. Wireline data are now routinely captured on a magnetic medium at predetermined sample increments. Increments vary from tool to tool, from service company to service company (even for comparable tools), and according to the depth recording system (English or metric) used by the service company. The quantity of data values recorded at a given depth increment can also vary. Most logging tools record only one value per increment for each specific trace (slow channel data). Others (for example, a full waveform acoustic tool) acquire multiple values at each depth increment (fast channel data) in order to later replicate and use the entire acquired range of values.

''Digital data'' are created by writing values into a file in numerical form. Wireline data are now routinely captured on a magnetic medium at predetermined sample increments. Increments vary from tool to tool, from service company to service company (even for comparable tools and [http://essaywriting.center essay writing service]), and according to the depth recording system (English or metric) used by the service company. The quantity of data values recorded at a given depth increment can also vary. Most logging tools record only one value per increment for each specific trace (slow channel data). Others (for example, a full waveform acoustic tool) acquire multiple values at each depth increment (fast channel data) in order to later replicate and use the entire acquired range of values.

Each wireline company has its own proprietary format for recording digital data. The two most common formats are LIS (the de facto standard) and BIT. Considerable efforts are being made to standardize all of the various formats into a single industry-wide standard known as the API digital log interchange standard, or DLIS.<ref name=pt08r8>Froman, N. L., 1989, DLIS—API Digital Log Interchange Standard: The Log Analyst, v. 30, n. 5, p. 390–394.</ref>

Each wireline company has its own proprietary format for recording digital data. The two most common formats are LIS (the de facto standard) and BIT. Considerable efforts are being made to standardize all of the various formats into a single industry-wide standard known as the API digital log interchange standard, or DLIS.<ref name=pt08r8>Froman, N. L., 1989, DLIS—API Digital Log Interchange Standard: The Log Analyst, v. 30, n. 5, p. 390–394.</ref>

===Advanced graphics===

===Advanced graphics===

Most of today's specialized high technology tools have developed specialized graphic displays of both raw and processed data. Understanding both the derivation and the presentation of the data is essential to understanding and interpreting the information presented. Examples include borehole imaging and dipmeter data (see [[Borehole imaging devices]] and [[Dipmeters]]).

Most of today's specialized high technology tools have developed specialized graphic displays of both raw and processed data. Understanding both the derivation and the presentation of the data is essential to understanding and interpreting the information presented. Examples include [[Borehole imaging devices|borehole imaging]] and [[dipmeter]] data.

==Data processing and output==

==Data processing and output==

[[Category:Integrated computer methods]]

[[Category:Integrated computer methods]]

[[Category:Petrophysics and well logs]]

[[Category:Petrophysics and well logs]]