Kim Senger
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BSc(Hons) title"Seismic interpretation of the Canterbury slope to identify links between gas hydrate occurrences and slope stability" SupervisorEmail senger.kim@gmail.com |
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Location of the field area off the east coast of the South Island, between Oamaru and Ashburton. |
Summary of project
Gas hydrates, solid compounds of small molecules set in an ice cage, form as these constituents come in contact with each other under specific temperature/pressure conditions. Ambient temperatures of <300K and moderate pressures of >0.6MPa , as well as presence of methane from bio-degradation of plant and animal matter buried in the seafloor. Gas hydrates are important as a possible source of natural gas, with even the most conservative estimates suggesting that energy stored in hydrates equates to twice that of all other fossil fuels combined . In addition, methane is a strong greenhouse gas and the destabilization of hydrate reserves may inflict abrupt climate change. Finally, the solid non-flowing nature of hydrates raises the question of flow assurance in oil and gas pipelines, where hydrate accumulations can cause blockages and thus pose a safety hazard. The occurrence of gas hydrate within continental slopes has also been linked to slope stability, with direct linkages between hydrate dissociation and sediment slumping.
Gas hydrates are presently identified primarily by the presence of a bottom simulating reflector (BSR). The horizontal BSR indicates the presence of gas at the base of the hydrate. The reflector is easily distinguishable in dipping strata but can be identified in horizontal strata given its negative reflection-coefficient. My project aims to investigate a substantial set of commercial marine seismic data from the Canterbury basin (Figure 1) and identify possible BSRs on the Canterbury slope. This will allow for an estimate for hydrate concentration on the Canterbury slope, an area of known natural gas reserves. In addition, I will attempt to map the areas of slope instability and see if there are any correlations with the occurrence of gas hydrates.