Updating seismic data management for the 4C/4D world

Jill Lewis and Robert Firth of Troika International say it is time to update exchange formats to meet the challenge of 4C/4D surveys highlighted by a huge explosion in data volumes. Information management and data exchange has always been a requirement in the world of hydrocarbon exploration. As an industry we have a completely different life cycle of data value than other industries. It is often quoted by record management experts that 95% of data loses its value in the first 18 months, and only the remaining 5% is ever looked at again. This is certainly not the case with exploration data, especially in those parts of the world where values may change dramatically due to geo-political or environmental issues. In order to support this extraordinary longevity, it is imperative that we are able to exchange information and have some commonality between data models and exchange formats. In the early days of exploration we had a very complex mixture of formats that were mainly driven by the architecture of the hardware. In most cases the format of digital field data was dictated by the acquisition system being used, and every processing contractor used their own proprietary format for processed data. This Tower of Babel situation was addressed by the standardisation efforts of the SEG, resulting in the SEGA/B/C formats for field data and SEGY for processed data. Although by this time general purpose computer systems were being used for seismic data processing, the gapless record structure used by the field formats meant that specialist tape controller hardware was required to read the data. This was a trade-off between the requirements of the acquisition and processing people. These issues were subsequently addressed by the SEGD format. On the other hand SEGY has proven to be extremely successful as an exchange format, although its limitations became increasingly apparent with the advent of 3D data, resulting in the recent revision of the SEGY standard.