澳大利亚波拿巴盆地N区块岩性圈闭识别探讨

澳大利亚N区块是海上勘探区块，钻探成本高，存在一定的勘探风险，尽可能地降低风险和找寻可能存在的最大圈闭资源规模，成为勘探的重点和难点。为此，在澳大利亚N区块开展了构造和岩性等多种类型圈闭的识别评价。在构造圈闭落实的情况下，利用澳大利亚N区块二维、三维地震资料，在高精度层序地层格架下，结合物源方向、古地貌和沉积体系空间配置关系分析，建立了岩性圈闭发育模式。通过目标层位的地震叠后属性、叠前同时反演等综合分析，采用纵横波速度比（Vp/Vs）等地震属性预测了岩性圈闭的分布特点及含油气性。在上述工作基础上，开展了岩性圈闭的油气成藏条件研究和圈闭资源量估算，扩大了澳大利亚N区块的资源规模，使其具备了一定的勘探价值。

Identification of lithologic traps in block N of Bonaparte Basin,Australia

The Block N in the Bonaparte Basin of Australia is an offshore exploration target with high drilling cost and exploration risk. The way to reduce the exploration risk as much as possible remains with the discovery of large traps. Therefore, the identification and evaluation of structural and lithologic traps have become a very important task. Based on the high-precision sequence stratigraphic framework established with 2D and 3D seismic data collected from the block, combined with the analysis of provenance directions, paleogeomorphology and spatial distribution of depositional systems, a depositional model for the lithologic traps is established in this paper. Through comprehensive study of post-stack attributes and pre-stack simultaneous inversion of the target horizon, the distribution patterns and oil-gas potential of the lithologic traps are predicted and evaluated using the seismic attributes such as P-wave velocity ratio (Vp/ Vs) etc. On the basis of the above work, we carried out the research again on the hydrocarbon accumulation conditions of the lithologic traps and the assessment of resource potentials. The resource scale of the block is substantially increased, which proves that the block is valuable for further exploration.