【摘要】 在地震资料解释中,传统描述强屏蔽层之下薄储层的方法是开一时窗提取属性,直接进行储层描述和预测。但由于强屏蔽层的覆盖作用,传统方法的解释结果不能突出下伏弱反射信息,储层预测效果受到较大影响。以五号桩油田沙二段隐蔽油气藏为例,分析T2强屏蔽层的地质成因,即沙一段底部存在1个致密的生物灰岩地层,构造上又是1个不整合,再根据声波测井和录井资料,制作正演模型,从地球物理机制上认证该结论。在强屏蔽层机理分析的基础上,提出了基于多子波分解重构理论的强屏蔽层剥离技术,并进行了模型试验和实际资料应用。研究结果表明,T2强屏蔽层剥离后提取的地震属性,能较好地反映储层的含油气分布,提高下伏目标层的预测精度,为此类隐蔽油气藏的勘探找到了1种新的途径。更多还原

【Abstract】 Traditional description and prediction of a thin reservoir under a strong shielding layer are directly carried out by extracting seismic attributes from a time window in seismic interpretation.However due to the coverage of the strong shielding layer,the interpreted result with the traditional method could not highlight the weak reflecting signals from the underlying layer,thus greatly affected the prediction result.In this paper,a subtle reservoir in Es2 of WHZ oilfield was taken as an example to analyze the geologic genesis of the T2 strong shielding layer and it was concluded that there was a consolidated biogenic limestone formation at the bottom of Es1 and the structure was unconformable.Then a forward model was established based on acoustic logging and mud logging data to confirm this conclusion in terms of geophysics.Finally,the technology of removing the strong shielding layer based on the theory of multi-wavelet decomposition and reconstruction was proposed and used in both simulation test and practice.The study results indicated that the seismic attributes extracted after removing the T2 strong shielding layer could better reflect hydrocarbon distribution in the reservoir,improve the prediction accuracy of the underlying target stratum and provide a new way to find such subtle reservoirs.更多还原