Where's the Data? Acquisition and Processing of Seismic Data in the PNG Highlands

Abstract

Seismic exploration in the PNG Highlands poses many challenges both in the acquisition and in the processing of the data. The seismic method is limited by both operational and technical constraints. These constraints push established seismic techniques to the very limit of their underlying principles. Operationally the remote location, rugose terrain, weather and Community Affairs issues are several of the numerous factors that make operations both difficult and, at times, dangerous. Technical issues include the complex sub-surface structure, karstified limestone, velocity inversion, and extreme topography. The operational issues and the geophysical effort needed to address the technical issues result in the cost of acquiring seismic data being very high, with seismic costing in excess of $200,000 per kilometre. This high acquisition cost makes 3D data uneconomic meaning that highly complex 3D structures have to be imaged on 2D data only. The seismic data acquired in the PNG Highlands is amongst the most difficult in the world to process. A primary reason for this is that the signal-to-noise ratio of the acquired data is very poor making many established processing techniques difficult to implement. In order to process the data it has been necessary to rethink many conventional approaches and come up with unique and novel ways of processing the data. Seismic data quality within the Highlands has always been an issue, and on a “non-fold-belt basis” the data would be considered of poor quality. The quality of the final processed data, although still poor when compared to other areas, has been continuously improved over many years. This paper will look at the various factors that affect the seismic data both in acquisition and processing and show how these issues are being addressed in order to produce a subsurface image that is of useable quality to the interpreters and geologists.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015