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 MR-DPTS in 1997 for the remastering of Petrobras’ 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 governmental 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 data base, 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 responsability to operate the bank. My personal involvement is the project is as PetroBank Project Coordinator for Petrobras. Currently, we have loaded all 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).
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 MR-DPTS). This project was initiated in December 1997, and the current status is:
1- about 800,000 pages of observer’s logs scanned (load will finish next month)
2- remaster to high capacity media and PetroBank load of 300,000 tapes with backup generation. Peak production of 18,000 tapes in one month.
3- recovery of sticky tapes
4- 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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