【摘要】 为系统梳理西湖凹陷Y区块断裂活动时空差异及控藏作用，在三维地震精细解释的基础上，按构造特征进行区带划分，采取平衡剖面法、断层活动速率法等技术，定性与定量相结合探究断裂体系差异演化特征，进而剖析断裂与油气成藏的时空配置，指明油气优势富集区。结果表明：西湖凹陷西斜坡新生代断裂体系具有深浅分层、南北分区差异，Y区块广泛发育四组方向的伸展断裂，深部大而少、浅部小而密，北部K构造以断阶分界断裂为主，构造样式单一，南部W构造样式较复杂，表现为断槽、低凸分界断裂相间；断裂演化经历断陷期、断-拗转换期和拗陷反转期，其中断陷期断裂活动最强烈，活动速率最大可达38.7 m/Ma,整体表现为早强晚弱、东强西弱、南强北弱的时空差异演变特征；Y区块大规模发育宝石组、平湖组下段优质烃源岩，在短距离汇聚脊和NNE向长期活动断裂联合输导作用下，在多类断层相关圈闭中聚集成藏。在此基础上，认为优势汇聚脊与NEE向断裂带结合部位，兼具早期强活动和晚期侧向封堵的断鼻及断层-岩性圈闭为优势富集区，W构造东侧低凸起、近洼带是最有利建产区。更多还原

【Abstract】 To systematically analyze the spatial-temporal differences in fault activity and its control on hydrocarbon accumulation in Block Y of the Xihu Depression, relied on detailed interpretation of three-dimensional seismic data. The area was divided into zones based on structural characteristics. Techniques such as balanced cross-section and fault activity rate methods were employed, combining qualitative and quantitative approaches to explore the differential evolutionary characteristics of the fault system. This led to an analysis of the spatial-temporal arrangement of faults relative to hydrocarbon accumulation, identifying areas with a higher potential for oil and gas enrichment. The results indicate that the Neogene fault system on the western slope of the Xihu Depression is characterized by deep and shallow stratification, as well as north-south zonal differences. Block Y extensively develops four groups of extensional faults, with deep faults being larger but fewer, and shallow faults being smaller but denser. The northern K structure is primarily defined by step faults, exhibiting a simpler structural style, whereas the southern W structure is more complex, characterized by fault troughs interspersed with low-convex boundary faults. The fault evolution underwent a rift phase, rift-thrust transition phase, and sag-reversal phase, with the rift phase showing the most intense fault activity, reaching maximum rates of 38.7 m/Ma. Overall, the evolution displays early strength diminishing over time, stronger activity in the east than the west, and stronger in the south than the north. Massive development of high-quality hydrocarbon source rocks in the Gem and Pinghu formations within Block Y, combined with short-distance convergent ridges and long-term active NNE-oriented faults, leads to hydrocarbon accumulation in various fault-related traps. Based on this, it suggests that the advantageous convergent ridges and NEE-oriented fault zones, which possess early intense activity and lateral sealing in the later stages at the nose and fault-lithology traps, are considered prime enrichment areas. The east side of the W structure’s low rise near the depression zone is identified as the most favorable production area.更多还原