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Hi all,

Recently we dug up some old logs and came accross these curves. ISF, BHC, LDL, CNL, LDT, NGT, HDT, WST.

The well was drilled in the 80's and I dont have any idea which service company logged it.

I tried to search the mnemonics in : http://www.spwla.org/cgi-bin/mnemonics_data_search.cgi

The results that came back were from various companies, hard to pin down the which company and which curve it represents.

Any of you have an idea which curves were run?

Thanks

Jeremy

Jeremey,

Difficult to figure this stuff out as there are so many log accronyms out there.

ISF might be: Instantaneous Frequency (could be from some sonic tool); BHC may stand for Borehole Compensated (or Caliper) and could be compensating other logs. Alternatively it could be the Standard Deviation on Sonic Transit Time (actually QBHC)

CNL could stand for a count rate and may be related to neutron or gamma measurements. More likely is thats it's the abbreviation for Compensated Neutron Log.

LDT could be a Delta-T Long from accoustic measurements (This website has a long list of accronyms for the most used well logs; albeit not searchable yet).

NGT might be from the Natural Gamma Ray Tool. HDT could be the Hole Depth or the High Resolution Dipmeter. WST is most likely the Well Seismic Too and is thus a measure of accoustic slowness (might match with your LDT).

LDL: no idea... With these pointer you may be able to figure some out based on value ranges and lithology matches. I think this wells has been logged with a sonic tool though...

hope that helped

Was thinking about this a little further. LDL is probably your Litho Density Log. No you have a proper tripple combo: GR, Density and Neutron Porosity and an extra sonic. Any resisitivity logs recongized? Check for them by setting your logs for logarithmic scales...

Also in techlog or Petrel you could generate logs from other mnemonics through the Log Estimator (in Petrel). This could also help you figure out what's wat.

Jeremy,

All these mnemonics are for Schlumberger logs.
ISF - Induction Spherically Focused log (resistivity logs)
BHC - Borehole Compensated Sonic log
LDL - Litho Density Log
CNL - Compensated Neutron Porosity Log
LDT - Litho Density Tool
NGT - Natural Gamma Ray Spectrometry tool
HDT - High Resolution Dipmeter tool
WST - Well Seismic Tool (for checkshot and VSP surveys)

The reason I know this is, because I was a Schlumberger engineer in my previous life.

Regards,
Ko Ko Kyi