Research Cruise Proposal : Light Hydrocarbon Geochemistry of the Bass, Otway, Stansbury and Gippsland Basins, and Torquay Sub-basin, Southeastern Australia : Project 9131.20

The measurement of the concentrations and molecular compositions of light hydrocarbon gases within the water column overlying offshore sedimentary basins can provide, under suitable circumstances, significant information on hydrocarbon source rock maturity and/or type, and the most likely locations for petroleum accumulation within basins. These measurements are usually made using a hydrocarbon 'sniffer', which comprises a submersible fish which is towed near the seafloor, and from which water is pumped to the surface and continuously analysed via gas chromatography. Compared with overseas, relatively few 'sniffer' surveys have been carried out around Australia, and hence the applicability and usefullness of this technique to the Australian situation is as yet undetermined.

As a continuation of its geochemical research program, the Division of Marine Geosciences and Petroleum Geology (Australian Bureau of Mineral Resources) will conduct a co-operative geochemical research survey withTransglobal Exploration and Geoscience (TEG) of Leucadia, California, USA, in southeastern Australia between February 1 and March 2, 1989. The cruise will be of 30 days duration and will involve work in the Gippsland, Bass, Otway and Stansbury Basins and the Torquay Sub-basin. A detailed proprietary program will be carried out in the Bass and Stansbury Basins in co-operation with Amoco Production Company. Two regional lines will be run from the Torquay Sub-basin, across the Cape Otway-King Island High, to the Crayfish Platform in the west of the Otway Basin (see Fig. 2). Regional lines will also be run in the Gippsland Basin, with an additional detailed program over several known oil and/or gas accumulations. In addition to the water column geochemistry, a limited sampling program will investigate the light hydrocarbon geochemistry of sediments over known oil and gas fieldsin the Gippsland Basin.

在适宜条件下，对覆盖近海沉积盆地的水柱中轻烃气体（light hydrocarbon gases）的浓度及分子组成进行测量，可提供关于烃源岩成熟度（hydrocarbon source rock maturity）和/或类型、以及盆地内石油聚集（petroleum accumulation）最可能位置的重要信息。这类测量通常使用烃类“嗅探器”（hydrocarbon 'sniffer'）进行，该装置包含一个在海底附近拖曳的潜水器（submersible fish），从潜水器中抽取海水至海面，并通过气相色谱法（gas chromatography）进行连续分析。与国外相比，澳大利亚周边开展的“嗅探器”调查相对较少，因此该技术在澳大利亚环境下的适用性和有效性尚未确定。

作为其地球化学研究计划的延续，澳大利亚矿产资源局（Australian Bureau of Mineral Resources）海洋地球科学与石油地质处将与美国加利福尼亚州勒卡迪亚的Transglobal Exploration and Geoscience（TEG）合作，于1989年2月1日至3月2日在澳大利亚东南部开展一项联合地球化学研究调查。该航次为期30天，将在吉普斯兰盆地（Gippsland Basin）、巴斯盆地（Bass Basin）、奥特韦盆地（Otway Basin）、斯坦斯伯里盆地（Stansbury Basin）及托基次盆地（Torquay Sub-basin）开展工作。将与阿莫科生产公司（Amoco Production Company）合作，在巴斯盆地和斯坦斯伯里盆地开展一项详细的专属项目（proprietary program）。将从托基次盆地布设两条区域测线（regional lines），穿过奥特韦角-金岛高地（Cape Otway-King Island High），延伸至奥特韦盆地西部的Crayfish平台（见图2）。此外，还将在吉普斯兰盆地布设区域测线，并在若干已知油气聚集区开展额外的详细项目。除水柱地球化学（water column geochemistry）研究外，还将实施一项有限采样项目，以调查吉普斯兰盆地已知油气田上方沉积物的轻烃地球化学（light hydrocarbon geochemistry）特征。