Natural gas accumulation conditions and exploration prospects of the Middle Permian Qixia Formation in the Sichuan Basin
Natural gas accumulation conditions and exploration prospects of the Middle Permian Qixia Formation in the Sichuan Basin
复制标题
四川盆地中二叠统栖霞组天然气成藏条件及勘探前景
DOI：
10.3389/feart.2022.980490
复制
发表时间：
2022
影响因子：
2.9
通讯作者：
Guangwei Wang
中科院分区：
文献类型：
--
作者：
Ya Zhang;Shuangling Chen;Long Wen;Benjian Zhang;Hua Wang;Di Xiao;Chen Xie;Xiaoli Zhang;Li Quan;Ran Liu;Yanping Qiao;Guangwei Wang
2010年以来，四川盆地中西部中二叠统栖霞组天然气勘探取得突破。通过对白云岩储集层和烃源岩的性质、圈闭类型、油气充注史等方面的研究，认为良好的成藏条件是栖霞组天然气大规模富集的基础。栖霞组优质储集层为白云岩，主要分布在加里东古隆起周围的沿着台缘和台内浅滩中。栖霞天然气主要来源于寒武系和二叠系泥岩烃源岩。上覆的二叠系烃源岩和下伏的寒武系烃源岩分布广泛，可为白云岩储层提供充足的气源。此外，栖霞白云岩与构造高点超覆形成的构造或构造-岩性圈闭也是油气聚集的有利条件。栖霞组自中晚三叠世至早白垩世经历了四期油气充注，构造高带圈闭最有利于油气聚集。因此，栖霞组具有形成大型气田的良好成藏条件。1号断层下盘隐伏构造带、龙门山-大兴场构造带及周边高磨-射洪古隆起是栖霞组大规模天然气勘探的重点地区。栖霞组是四川盆地继埃迪卡拉系灯影组、寒武系龙王庙组之后天然气勘探的重要战略接替气田。
Exploration of natural gases in the Middle Permian Qixia Formation has achieved a breakthrough in the central and western Sichuan Basin since 2010. This study discusses the quality of dolomite reservoirs and source rocks, trap types and hydrocarbon charging history and proposes that good accumulation conditions are the basis for the large-scale enrichment of natural gas in the Qixia Formation. The high-quality reservoirs in the Qixia Formation are dolomites that primarily occur along platform margins and in the inner-platform shoals surrounding the Caledonian palaeo-uplifts. The Qixia gases originated mainly from the Cambrian and Permian mudstone source rocks. The overlaying Permian source rocks and the underlying Cambrian source rocks are both widely distributed and could provide sufficient gases for dolomite reservoirs. Additionally, the structural or structural-lithologic traps formed by an overlap of the Qixia dolomites and structurally high are favourable for oil and gas accumulation. The Qixia Formation had experienced four episodes of oil and gas charging from the middle-late Triassic to the Early Cretaceous, and traps located in structural-high zones are most favourable for hydrocarbon accumulation. Thus, the Qixia Formation has excellent accumulation conditions for the formation of large-scale gas fields. The concealed structural belts in the footwall of fault No. 1, the Longmenshan–Daxingchang structural belts and the periphery Gaomo–Shehong palaeo-uplift are the key zones for large-scale gas exploration in the Qixia Formation. The Qixia Formation is an important strategic replacement field for natural gas exploration in the Sichuan Basin following the Ediacaran Dengying Formation and the Cambrian Longwangmiao Formation.