深水水道形态定量分析及沉积模拟——以西非Gengibre油田为例

由于深水水道油藏多位于深海区,受作业成本限制,其开发井距往往较大,难以通过密井网多井拟合获取沉积定量关系.为此,利用西非Gengibre油田深水区浅层沉积高频地震资料,对陆坡区深水水道沉积特征和定量关系进行了研究,并指导深层稀井网油田水道储层模拟,提出了基于沉积定量分析的深水水道模拟思路.研究结果表明:单一水道呈整体迁移方式,迁移模式包含"侧向迁移"和"沿古流向迁移"2种类 型,定量沉积分析结果认为单一水道的宽度与深度之间存在较好的正相关性;浅层高频地震资料弥补了深层地震分辨率不足的缺陷,稀井网下深水水道模拟选用基于目标方法更为合适,模拟结果符合地质认识;将沉积定量认识整合到沉积相建模中,拓宽了相建模的思路,具有推广价值.研究成果不仅可以完善深水水道定量分布模式,而且对于高效开发深水水道油藏具有实用价值.

Morphology quantitative analysis and simulation of deepwater channel: a case study of Gengibre oilfield in west Africa

Since most oil reservoirs of deepwater channel are located in abysmal area, the well spacing is large as limited by operation cost, and thus it is difficult to obtain the depositional quantitative relationship between channels through multi-well fitting in dense well pattern. Therefore, the quantitative relationship and sedimentary characteristics of deepwater channel in slope area were studied using the high-frequency seismic data of deepwater shallow sediments of Gengibre oilfield in west Africa, thus guiding the simulation of channel reservoirs in deep-buried sparse well pattern of oilfield. Then a deepwater channel simulation scheme was proposed based on depositional quantitative analysis. The results show that single channel presents an overall migration pattern, which includes migration along palaeo-current and lateral migration. The quantitative analysis results indicate there exists a relatively good positive correlation between the width and depth of single channel. The shallow-layer high-frequency seismic data compensates for the low resolution of deep-layer seismic data. Object-based simulation method is more applicable for deepwater channels in sparse well pattern, and the simulation result is consistent with geological knowledge. The integration of quantitative depositional knowledge into sedimentary facies modeling has expanded the idea of reservoir modeling and is worth to be promoted. The research result can not only improve the quantitative distributional pattern of deepwater channel, but also has a practical value for effectively developing deepwater channel reservoirs.