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su 的源代码库

The files in this directory allow to convert a LAS file to SU format.

The procedure is simple:

1) Strip off LAS header.
   This results in two files being written into the current directory:
   las_header.asc containing the header information, and
   a file las_data.asc containing the data channels,
   both in ASCII format.

2) Convert las_data.asc from ASCII to BINARY.

3) Transpose obtained binary data to have data channels in rows
   instead of columns.
   
4) Add SU header.

5) Set SU header words.

6) Remove depth channel (= 1st trace). This requires a modified SUWIND.


For convenience there is a shell script that implements all the above steps. To run it type the following

      ******************************************************
      * ./las2su.sh  lasfile  ndc  nsamp  start  dz  units *
      ******************************************************
	
where

	lasfile		original data file in LAS format
	ndc		no. of data channels (logs) in LAS file
	nsamp		no. of samples = (start-stop)/dz +1
	start		start depth in F or M
	dz		sampling interval in F or M
	units		F or M
.

There is a test LAS file included, which was taken from the trial version of Digital Formation, Inc.'s LESA package.

At the time of writing this, SU did not have trid's assigned to identify the different well logs. Here is a minimum suggestion:

trid	well log	description
------------------------------------------------
300	GR		total gamma ray
301	SP		spontaneous potential
302	CAL1		caliper 1 (e.g. x-axis)
303	CAL2		caliper 2 (e.g. y-axis)
304	MLN		2" microlog normal
305	MLI		1" microlog inverse
310	RXO		flushed zone resistivity
311	RM		medium resistivity
312	RD		deep resistivity
320	NPHI		neutron porosity
321	RHOB		bulk density
322	DRHO		bulk density correction
323	PEF		photoelectic factor
330	DTC		compressional delta T
331	DTS		shear delta T
332	DTST		Stoneley delta T
335	VP		compressional velocity
336	VS		shear velocity
337	VST		Stoneley velocity
340	ZP		P impedance
341	ZS		S impedance
350	TENS		cable tension
351	DEV		well deviation
352	HAZI		hole azimuth
etc. ...

The idea is that

300-309	lithology indicator & borehole geometry logs
310-319	resistivity logs
320-329	nuclear logs
330-349	sonic logs and derivatives
350+	auxiliary logs


Best regards & good luck,
Werner M. Heigl