【摘要】 在裂谷盆地油气构造圈闭研究中,盐岩的沉积使得构造圈闭类型复杂多样化,同时也增加了油气勘探的难度,尤其是盐下油气勘探的难度。以苏丹红海裂谷盆地作为研究实例,利用比例化物理模拟实验探讨含盐裂谷盆地盐相关构造演化机制和影响因素,并结合研究区地震剖面和地层岩性特征讨论其对油气构造圈闭形成和油气成藏的影响。模拟实验结果表明,同裂谷沉积及基底断裂作用是影响苏丹红海盆地内盐构造演化的2个主要控制因素。同时,原始盐岩沉积厚度对盐构造演化及样式也有重要的影响。综合实验模拟结果和研究区地震剖面分析认为苏丹红海裂谷盆地盐上构造圈闭主要类型有盐构造相关的遮挡圈闭、滚动背斜圈闭和披覆构造圈闭;盐下构造圈闭主要为断背斜等基底断块相关的构造圈闭。此外,受地层岩性特征和盐岩沉积及构造分布等影响,盆地形成盐上自生自储、盐下下生上储2套油气成藏模式。对比分析显示盐上、盐下储集层性能相当,但盐下油源条件较盐上好,且存在致密的盐岩层盖层和丰富的基底断裂油气运移通道。因此,综合分析认为苏丹红海裂谷盆地盐下断块油气成藏具有巨大的潜力,可以作为未来油气勘探的重点领域。更多还原

【Abstract】 In rift basins,salt rock deposition leads to the formation of complex and diverse types of oil-and gas-bearing structural traps,greatly increasing the difficulty in oil and gas exploration,especially in subsalt strata.Taking as an example the Sudanese Red Sea rift basin,this study explored the evolutionary mechanism and influencing factors of salt-related structures in rift basins through scaled physical modeling.Combined with seismic profiles and stratigraphic lithology,this paper discussed the significance of salt-related structures to the formation of oil-and gas-bearing structural traps and associated hydrocarbon accumulation.The results from physical modeling indicate that syn-tectonic deposition and basement faulting are two major factors influencing the evolution of salt-related structures in the Sudanese Red Sea rift basin.Additionally,the initial thickness of salt rocks has a significant impact on the evolution of salt-related structures.Combined with the interpretation of seismic profiles,it is considered that in the Sudanese Red Sea rift basin include,the major types of supra-salt structural traps include salt-related barrier trap,rolling anticline trap and drape fold trap,whereas the sub-salt structural traps mainly include basement-fault-block-related structural traps such as fault-related anticlines.Due to the influence of stratigraphic lithology,salt rock deposition and salt structure distribution,two oil-and-gas-accumulation systems are developed in the rift basin:the self-generating and self-preserving reservoir in the supra-salt strata,and the lower-generating and upper-preserving reservoir in the subsalt strata.Comparison analysisshows that the supra-and sub-salt reservoirs have comparable properties.However,the sub-salt reservoir has better hydrocarbon source rocks,which contains a dense salt rock cover and abundant pathways for hydrocarbon migration through the basement faults.Hence,it is believed that the sub-salt basement fault blocks have huge potential for oil and gas accumulation and provide an important area for future oil and gas exploration in the Sudanese Red Sea rift basin.更多还原