珠江口盆地西部文昌A凹陷古近系天然气富集主控因素与勘探方向

Main controls over Palaeogene natural gas accumulation and its exploration direction in Wenchang A sag,the western Pearl River Mouth basin

分析了珠江口盆地西部文昌A凹陷构造演化、沉积体系及其对古近系天然气成藏组合时空分布的控制,认为珠海组二、三段(扇)三角洲及潮坪砂-断背斜是主要的天然气成藏组合,恩平组断陷湖扇三角洲砂-断背斜是潜在的天然气成藏组合。对新近系天然气难以大规模成藏的原因进行了分析,指出了古近系天然气富集的主控因素和下一步天然气勘探的有利区带。

By analyzing the structural evolution, sedimentary systems and their controls over the time and space distribution of Palaeogene gas plays in Wenchang A sag, the western Pearl River Mouth basin, it can be concluded that the fan delta sand and tidal-flat sand-faulted anticline in Member 2 and 3 of Zhuhai Formation are the main gas plays, and that the rifted-lake fan delta sand-faulted anticline in Engping Formation is a potential gas play. In addition, the reasons why Neogene gas is difficult to form great accumulations are analyzed, and the main controls over Palaeogene gas accumulation and its favorable future exploration trends are indicated.