Analysing sand-dominated channel systems for potential gas-hydrate-reservoirs using an AVO seismic inversion technique on the Southern Hikurangi Margin, New Zealand

作者：Fohrmann M^*; Pecher I A

来源：Marine and Petroleum Geology, 2012, 38(1): 19-34.

DOI：10.1016/j.marpetgeo.2012.08.001

• Gas hydrate
• New Zealand
• Sands
• Channel systems
• Bottom-simulating-reflection (BSR)
• Amplitude-versus-offset (AVO)

Gas hydrates have recently been recognised as a class of unconventional petroleum resource and the economic viability of gas production from hydrates is now being viewed as a realistic possibility within the next decade. Therefore, potential offshore hydrate accumulations in the world-class endowed gas hydrate province, the Hikurangi Margin, New Zealand, represent a significant medium- to long-term opportunity to meet the country%26apos;s future energy requirements. %26lt;br%26gt;In this paper we delineate a potential gas hydrate reservoir in the East Coast Basin, New Zealand and quantitatively estimate its gas hydrate concentrations from 2D seismic data with no well information available. %26lt;br%26gt;The target is interesting for exploration since it shows evidence for gas-hydrate bearing sands, in particular, buried channel systems. We use a combined analysis of high-resolution velocity analysis, amplitude-versus-offset (AVO) attribute and AVO inversion to investigate whether we can identify regions that are likely to contain highly concentrated gas hydrates and whether they are likely to be sand-dominated. To estimate hydrate concentrations we apply a rock physics model. %26lt;br%26gt;Our results indicate the presence of several - up to 200 m thick - zones that are likely to host gas hydrates, with one location predicted to consist of high-permeable channel sands and an inferred gas hydrate saturation of similar to 25%. These findings suggest significant amounts of gas hydrates may be present in high-quality reservoirs on this part of the margin.

• 出版日期2012-12