西非尼日尔三角洲盆地发育深水扇沉积体系,钻井资料揭示,油层和水层均表现为"亮点"和远道增强的Ⅱ、Ⅲ类AVO异常,利用常规振幅和AVO方法检测烃类精度低.为此,首先分析了地震响应特征及其影响因素,通过正演模拟明确了孔隙度是引起振幅及AVO多解性的主要原因;然后,通过交会分析认识到,截距—梯度属性随孔隙度的变化规律与随含水饱和度的变化规律存在差异,进而提出了基于坐标旋转的扩展AVO属性,以降低常规AVO属性的多解性,提高油气预测精度;最后,开展面向实际储层的敏感流体因子优选,提出一种新的流体因子敏感性定量分析方法,能够优选出对流体敏感、对孔隙不敏感的流体因子,预测结果能够压制孔隙度造成的流体识别假象.分析结果表明,λ/(λ、μ为拉梅系数)具有对流体性质敏感性高、对孔隙度敏感性低的特征,是研究区开展烃类检测的最佳敏感流体因子.实际应用结果表明,利用扩展AVO属性和λ/μ流体因子能够有效区分真"亮点"油层和假"亮点"水层,预测结果与钻井数据更吻合,有效提升了烃类检测成功率.

PreviousNext No AccessSEG 2020 Workshop: Broadband and Wide-azimuth Deepwater Seismic Technology, Beijing, China, 13–15 July 2020Frequency-dispersion AVO analysis in deepwater area of the South China Sea: A case study of X21-1Authors: Cong NiuYun LingDi WangWei CuiYuhua ZhangCong NiuCNOOC Research institute Co. Ltd., Beijing, ChinaSearch for more papers by this author, Yun LingCNOOC Research institute Co. Ltd., Beijing, ChinaSearch for more papers by this author, Di WangCNOOC Research institute Co. Ltd., Beijing, ChinaSearch for more papers by this author, Wei CuiCNOOC Research institute Co. Ltd., Beijing, ChinaSearch for more papers by this author, and Yuhua ZhangCNOOC Research institute Co. Ltd., Beijing, ChinaSearch for more papers by this authorhttps://doi.org/10.1190/bwds2020_16.1 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract Due to few or a few drilled wells in the deepwater area, conventional technologies such as seismic inversion without constraining from logging can generate multiple solutions in detecting oil and gas. According to the seismic wave attenuation and velocity dispersion, the frequency-dependent AVO equation is used to calculate the dispersive properties of seismic wave based on seismic spectrum decomposition. And then through combing AVO frequency dispersion analysis with AVO attributes, we study the gas-bearing possibility of X21-1 in the deepwater area of the South China Sea. The favorable gas-bearing zones are predicted. The predicted result is in good correspondence with actual drilling results. The research results demonstrate that in the same conditions, the dispersion property of saturated gas is significant larger than that of saturated water, and the frequency-dispersion AVO properties can be used as hydrocarbon indicators. Keywords: deepwater, dispersion, amplitude-versus-offset, modeling, loggingPermalink: https://doi.org/10.1190/bwds2020_16.1FiguresReferencesRelatedDetails SEG 2020 Workshop: Broadband and Wide-azimuth Deepwater Seismic Technology, Beijing, China, 13–15 July 2020ISSN (online):2159-6832Copyright: 2020 Pages: 155 publication data© 2020 Published in electronic format with permission by the Society of Exploration GeophysicistsPublisher:Society of Exploration Geophysicists HistoryPublished Online: 09 Nov 2020 CITATION INFORMATION Cong Niu, Yun Ling, Di Wang, Wei Cui, and Yuhua Zhang, (2020), "Frequency-dispersion AVO analysis in deepwater area of the South China Sea: A case study of X21-1," SEG Global Meeting Abstracts : 57-61. https://doi.org/10.1190/bwds2020_16.1 Plain-Language Summary Keywordsdeepwaterdispersionamplitude-versus-offsetmodelingloggingPDF DownloadLoading ...