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The original Petrobras project to organize its seismic data
was initiated in the early ‘90’s. The IBM/PGS Petrobank software
in 1995 and contract was signed with PGS and DPTS in 1997
for the remastering of Petrobas’ seismic archive. Remastering
operations began for real in December 1997.
Changes
Since the project started, there have been considerable changes
in Brazil’s oil sector. The Petrobras monopoly has ended and
the Brazilian government has created a new agency, the ANP
which governs the petroleum industry’s activity in Brazil.
The ANP decided to put the Petrobras data into the public
domain and to refund Petrobras for the cost of the data itself
and for the remastering costs. The public domain rules concern
5 year old seismic data, and 2 year old well logs. This led
to the concept of a single database, a national repository
based on PetroBank, sharing data management costs and making
data easily available to industry.
The Banco de Dados E&P (BDEP) has been on-line since April
2000. BDEP is a consortium of oil and services companies,
including (and sponsored by) ANP. ANP has handed to CPRM (Brazilian
Geological Service) the responsibility to operate the bank.
My personal involvement in the project is as PetroBank Project
Coordinator for Petrobras. Currently, we have loaded well
logs, about 80% of the post-stack seismics, and about 60%
of the pre-stack seismic available in Brazil (acquired by
Petrobras in the monopoly period).
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Public domain
Most of this data is in the public domain and is now available
to industry. I think that the pre-stack part of the project
is the most exciting one, (sub-contracted to PGS and DPTS).
This project was initiated in December 1997, and current status
is:
- About 800,000 pages of observer’s logs scanned (load will
finish next month).
- Remaster to high capacity media and PetroBank load of
300,000 tapes with backup generation. Peak production of
18,000 tapes in one month.
- Recovery of sticky tapes.
- Original media destruction – 30,000 already destroyed.
Confidence
Loading pre-stack data into PetroBank requires accurate metadata
linking files, geometry and shotpoint coordinates. Obtaining
this information requires a lot of effort, but it’s the only
way to get high quality, useable data, and to have enough
confidence in the transcription process to be able to destroy
the originals. The 300,000 tapes remastered to date have been
selected following the analysis of some 350,000 tapes (10%
were duplicates and were discarded, and 4% missing something
– coordinates, obs logs). People often believe tape remastering
is straightforward work. It is not! Remastering is a complex
process, much more than just changing tapes. This work can
add significant value to the seismic archive.
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