刘嘉榆1, 李涛1, 杨光2, 胡佳2, 张珈畅1, 蔡雨汛1
LIU Jiayu1, LI Tao1, YANG Guang2, HU Jia2, ZHANG Jiachang1, CAI Yuxun1
摘要： 为明确长岭断陷主干控洼断层构造特征及其活动性对油气成藏的影响,通过对长岭断陷骨干地震剖面的精细解释和平衡剖面恢复分析,选用生长指数、古落差和活动速率3个指标综合分析各个洼槽主干控洼断层的活动特征,探讨了断层活动对长岭地区各洼槽的演化、圈闭形成和油气成藏的影响。研究表明:长岭断陷主干控洼断层经历了多期活动且具有明显的继承性,在垂向上沟通了多个层系,为油气运聚提供有利的输导条件及成藏区域。断陷期断层活动最活跃,沙河子组烃源岩大量生油,沿主干断层进行侧向和垂向输导;断陷衰减期大部分断层受拉张应力形成同沉积断层,并在局部地区发育同沉积背斜、逆牵引构造和鼻状构造等;拗陷期断层活动减弱或停止,大部分断层起到封闭作用;反转期断层受挤压应力形成反转断层,油气藏发生调整和再运移。长岭断陷东西向为“三堑夹两垒”的分带特征,各洼槽结构演化存在一定差异,影响了长岭断陷内部洼槽成藏模式。该研究深化了对长岭断陷控洼断层构造特征的认识,可为控洼断层对成藏模式的影响评价提供借鉴。
Abstract: To clarify the tectonic features of the major control faults of the Changling Fault-Depression and the influence of their activity on hydrocarbon accumulation, this article analyzed the activity characteristics of the major control faults of each depression using growth index, paleo-displacement, and activity rate through the fine interpretation of the key seismic profiles of the Changling Fault-Depression and the restoration analysis of the balanced profile, and discussed the influence of the fault activity on the evolution of each depression in the Changling Area, the formation of the trap, and the formation of the oil and gas reservoirs. The study shows that the major control faults of the Changling Fault-Depression have experienced multi-phase activity with inheritance, connecting multiple series of strata and providing favorable conduits for hydrocarbon migration and accumulation. At the syn-rift stage, active faulting enabled large-scale oil generation from Shahezi Formation source rocks, with lateral and vertical migration along the major faults. At the rift attenuation stage, most faults became syn-sedimentary due to tensional stress, forming local syn-sedimentary antic, reverse drag structures, and nosing structures. At the post-rift stage, fault activity declined or ceased, with most faults acting as seals. At the inversion stage, faults were compressed into inverted faults, causing hydrocarbon reservoir adjustment andremigration. The Changling Depression has an east-west-trending "three grabens interspersed with two horsts" zonation. Structural evolution differences among depressions affect the accumulation mode of depressions in the Changling Fault-Depression. This study enhances understanding of the tectonic features of the major control faults of the Changling Fault-Depression and offers insights into evaluating the impact of such faults on accumulation modes.
中图分类号:
刘嘉榆, 李涛, 杨光, 胡佳, 张珈畅, 蔡雨汛. 长岭断陷断层演化特征及油气意义[J]. 特种油气藏, 2025, 32(4): 77-86.
LIU Jiayu, LI Tao, YANG Guang, HU Jia, ZHANG Jiachang, CAI Yuxun. Fault evolution and hydrocarbon significance in the Changling Fault-Depression[J]. Special Oil & Gas Reservoirs, 2025, 32(4): 77-86.