Geophysical Transcription
Geophysical transcription is a process where old tapes & cartridges containing still valid seismic data, typically encoded in outdated no-longer supported formats, are moved to new higher density media. At the same time the data is converted/transcribed from the obsolete format to a more accessible commonly used one. For most people's purposes this format is SEGY. SEG (Society of Exploration Geophysicists) format Y, was actually first defined in 1973, and somehow has managed to remain standardized. Every seismic software package knows what it is and how to read & write it, and so by default it is the standard Interchange format.
There are over 1500 seismic formats that we know of. These consist of what we call "Field" formats and "In-House" formats.
A Field format refers to the raw seismic data acquisition format, whether the data was obtained on the high seas, in the desert sands or even in the jungle (i.e. Outside of the office/Data Center). There are a few standards here - SEG-A (16 bit), SEG-B (20 bit), SEG-C (32 bit FL) and SEG-D, which can be anything from 12 bit to 32 bit. The standard field acquisition format today is SEG-D, while some marine based Geophysical contractors gather data in SEG-Y. The SEG formats are well documented, well understood and with the exception of some SEG-D variations (where 3D cross & sub-line information is encoded in the header), can be handled with ease by most software packages.
Some of these tapes are now over 30 years old, and while we understand HOW to read the tape, the physical condition of the media often makes this difficult. When you compound this with the high acquisition costs of a tape (sometimes many $10,000's per tape) (with a correspondingly high data value), correctly recovering and reading of these tapes becomes critical.
In-House formats are more difficult to deal with. These are custom formats written by a geophysical processing contractor for their exclusive in-house use. They are designed to be used with their own internal software and are not meant for the outside world - hence they are not standardized; are often poorly documented; are often inconsistent (due to lousy coding or format design revisions) and in a lot of cases, were designed and written by companies that have long since ceased to exist. To compound this further, data written in these formats is written on media that may have been used 100's of times before the data was archived, and so the actual condition of the media itself is often very poor. Hence we are dealing with poorly documented formats/data layouts on failing media - a recipe for disaster.
There are several generic problems that occur with tape, which are caused by age/heat/humidity/improper storage and each has to be recognized and dealt with properly or the data will be lost forever. Old tape can break, shred (literally the oxide will peel off of the Mylar substrate), or become unreadable due to Stiction. Stiction is a common process where the binder that holds the "data" (stored on the magnetic oxide) to the "tape" breaks down in the form of erratic levels of lubrication on the tape surface, leaving behind a sticky mess that literally, in the worst cases, glues the tape to itself, and ultimately the tape head. Essentially, the internal lubricant that helps the tape move over the heads has separated from the tape itself and is literally causing the tape to stick to itself.
eMag has a very knowledgeable staff of data recovery experts. As media manufacturers for the last 30 years, we have unique insights into how a tape is formulated and made, as well as what it takes to correctly treat and recover faulty media. We are specialists in knowing how to treat tape on a brand-by-brand, and in some cases batch-by-batch basis. Media conditioning and stabilization MUST be achieved before attempting to mount the tape on a drive. Some tapes require baking, while others require hand lubricating where the tape is manually un-spooled inch-by-inch and treated so as it make it readable. In some cases there is only one chance to read the "fixed" tape, so again, the hardware has to be appropriate and robust and intelligent enough to understand how to process such media. This is NOT a job for someone with some software and a couple of drives. It requires deep knowledge along with skill & attention to detail.
Reading a tape is one thing - understanding what you are reading is something else altogether. Our programming staff has written code to process over 1500 format variations and can safely say that there is no " format that we cannot correctly interpret and transcribe, with full QC capabilities that allow seismic data to be viewed while transcribing. We also have extensive systems integration experience, where not only can we copy your tapes, but we can also interface to your libraries and even upload data to systems like Petrobank, if need be.
Our website contains a high level overview of our Geophysical Transcription services, explaining why they are needed and how you'd benefit from them. If you'd like to inquire about eMag safely and expertly recovering and transcribing your data, please contact us.
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