地震沉积学在白云岩油藏隔夹层预测中的应用——以塔里木盆地英买32区块蓬莱坝组为例

Application of seismic sedimentology to prediction of interbeds in dolomite reservoir: A case study of Penglaiba Formation in Yingmai 32 block of Tarim Basin

塔里木盆地英买32区块蓬莱坝组白云岩油藏隔夹层的广泛发育增加了剩余油挖潜的难度。由于隔夹层厚度薄,分布规律不清楚,准确预测其分布已成为该区研究的难点之一。在地震沉积学理论指导下,建立高频层序格架,利用谱反演处理后的地震资料和90°相位化,以及野外地质建模指导下的地层切片等技术,预测了该区隔夹层的分布规律。谱反演处理能有效提高地震资料对薄层的识别能力,且90°相位化后的地震同相轴与隔夹层有较好的对应关系;野外地质建模明确了隔夹层平面分布规律,且与钻井资料有较好的对应关系,能有效指导地层切片对井下隔夹层空间的分布预测。预测结果表明,隔夹层呈北西—北东向条带状分布于研究区的东北部,控制着研究区剩余油的分布。通过钻井测试和生产资料验证,该方法预测的隔夹层分布结果准确、可靠。

The widely development of interbeds in dolomite reservoir of Penglaiba Formation increased the difficulty of remaining oil mining in Yingmai 32 block in Tarim Basin. Due to the small thickness of the interbed and the unclear distribution regularities, it is difficult to predict the interbed distribution in the study area. Under the guidance of seismic sedimentology theory, techniques such as 90° phase convert after spectrum inversion and strata slice in outcrop modeling were used to predict the distribution rule of interbeds in high frequency sequence stratigraphic framework. The result shows that spectrum inversion can improve the ability of thin layer resolution, and there is a better corresponding relation between seismic event and thin layer. The outcrop modeling determines the distribution rule of interbeds, and there is a better corresponding relation with well data, which can guide the prediction of interbed distribution. The prediction result shows that the interbeds distributed in the northeast of the study area, and they control the distribution of remaining oil. Finally, by well data verification, it proves that the interlayer distribution predicted by this method is accurate and reasonable.