论文详情
深水重力流水道为深水油气勘探的重要目标,水道砂体埋藏深、探井少,砂体识别及厚度预测困难;同时相带及岩性横向变化快,多期水道砂体叠置导致储层非均质性强。因此,精细刻画水道分布并预测优质储层发育区是勘探开发亟需解决的问题。为此,提出了基于地震构形的相控储层预测技术。首先,在地震资料高分辨率处理的基础上,在相对年代域提取横向梯度属性刻画水道边界,利用Wheeler域数据体连续切片分析水道演化;以地震构形为约束,利用改进的标准抛物线型三参数AVO方程,构建有利岩相敏感地震属性表征岩性相。综合水道边界刻画与有利岩相预测结果,预测优势储层发育区。采用该技术有效刻画了南海某凹陷重力流水道砂体分布。预测结果表明,优势储层集中发育于北西向水道主体部位,与区域沉积规律及认识吻合,证实了方法的有效性。
Deep-water gravity flow channels are important targets for deep-water oil and gas exploration.However,deeply-buried channel-shaped sand bodies are generally reached by only a few exploratory wells.Therefore,identifying these sand bodies and predicting their thickness is difficult.Furthermore,the facies belt and lithology exhibit substantial spatial variations,and the superposition of multi-stage channel sand bodies leads to a strong reservoir heterogeneity.Therefore,achieving an accurate description of the spatial patterns of waterways is an urgent task in exploration and development,which allows the prediction of development areas for high-quality reservoirs.To this aim,a facies-controlled prediction method based on seismic configuration is proposed in this work.First,based on high-resolution seismic data processing,the lateral gradient attributes are extracted in the relative chronological domain to describe the channel boundary,and the channel evolution is analyzed via a serial slice of the Wheeler volume.The seismic configuration is used as a constraint,and an improved standard parabolic three-parameter amplitude-versus-offset equation is used to construct favorable lithofacies-sensitive seismic attributes to characterize the lithologic facies.The channel boundary description and favorable lithofacies prediction results are then combined to predict the development area of dominant reservoirs.The proposed method was implemented on the gravity flow channel of a sag in the South China Sea to effectively characterize the distribution of sand bodies.The prediction results showed a concentration of dominant reservoirs in the main part of the northwest-trending channel,consistent with the regional depositional law and current geological understanding,thereby confirming the effectiveness of the method.
国家科技重大专项(2016ZX05024-005-003)资助。