西非泽塔油田1#层剩余油分布时移地震预测

西非深海泽塔油田受深水油田技术及经济条件的限制，开发10年来，注采井网水驱方向不明确，层间水驱程度不均衡，井间、层间矛盾突出，无法准确确定剩余油富集位置。针对主力产油层1^#油层，优选了基于时移地震差异数据的相邻道相关系数为剩余油预测的敏感属性。经三次监测地震差异数据的实际应用，不仅可以清楚地反映注水驱替动态变化，而且可以较好地刻画注水前缘位置，结合油田构造、砂体分布和时移地震差异相关系数，成功预测了剩余油分布区，并获得以下认识：第一，无论疏松砂岩储层含油或含水，其波阻抗均小于上覆深海泥岩，此为利用时移地震动态监测油藏开发的岩石物理基础；第二，时移地震差异基本可以反映油水驱替的范围和方向，其中相关系数属性对油水驱替更敏感，可以更好地刻画各期油水驱替前缘位置；第三，综合油田构造、砂体分布和时移地震差异相关系数等资料预测了2013年油藏1^#油层的3个剩余油分布区，其中区域Ⅱ的I-2井以南部分和区域Ⅲ可能为剩余油永久滞留区，有待进一步钻井证实。

Remaining oil prediction based on time-lapse seismic data in Layer 1#, Zeta Oilfield

Zeta Oilfield in the deep sea of West Africa has been developed for more than 10 years,and water displacement has been adopted for oil production for some time.However remaining-oil enrichment zones cannot be determined due to unclear directions of water flooding in injection-production well patterns and uneven displacement for different layers.To solve the problem,we carry out a research on the main oil bed,Layer 1^#,and predict remaining-oil enrichment zones based on time-lapse seismic data.The adjacent-trace correlation coefficient on the time-lapse seismic data is optimized as a sensitive attribute for remaining oil prediction.Both the dynamic change of water flooding displacement and the water flooding frontier are clearly delineated on time-lapse seismic data.With the integration of geological structures,sand-body distribution,and adjacent-trace correlation coefficient,remaining oil enrichment zones are successfully predicted.And the following understandings are obtained:A.The impedance of oil-or water-content unconsolidated sand reservoirs is smaller than that of overlying deep-sea mudstone; B.The differences of time-lapse seismic data can basically indicate the range and direction of oil-water displacement,in which the correlation coefficient is more sensitive than others,it can better describe the edge position of oil-water displacement in the period of monitor survey acquisition; C.Based on the comprehensive analysis of oilfield structures,sand-body distribution,and correlation coefficient,three remaining oil zones of Layer 1^# in 2013 are predicted,among which Zone Ⅲ and the southern part to Well Ⅰ-2 in Zone Ⅱ might be residual oil permanent retention zones.They need to be confirmed by further drilling.