沉积成因约束的辫状河三角洲泥质夹层表征

Braided River Delta Muddy Interbed Characteristics with Sediment-contributing Factors as Control

由于缺少岩芯、动态资料不完善,海上稀井网油田精细表征储层和泥质夹层分布规律难度较大。为尝试解决这个问题,将珠江口盆地X油田珠江组海相砂岩储集层作为研究对象,以高质量地震资料和测井资料为基础,并借鉴陆上相同沉积环境的露头研究成果,分析泥质夹层的响应特征。结果表明,研究区辫状河三角洲泥质夹层有小规模海泛成因、堤岸成因及前积成因等3种类型。为满足生产需求,可将夹层划分为3个级次。在级次划分方案的基础上,以地震属性资料作为约束沉积相展布研究的基础,通过剖-平联动,确定了不同级次、不同成因夹层的空间分布特征。利用确定性建模和随机建模相结合的手段,表征和预测了不同成因夹层的空间分布特征。

Due to insufficient core and dynamic data,it is difficult to precisely characterize the distribution patterns of reservoirs and muddy interbeds in offshore oilfields with scarcely scattered well networks.To resolve this issue,we chose the marine sandstone reservoir of the Pearl River Group-X Oilfield located in the Pearl River Mouth Basin as the research subject.We used high-quality seismic and well-logging data combined with research results of numerous studies of similar on-land sedimentary environments to analyze the characteristics of muddy interbeds.The results show that three types of factors contribute to the muddy interbeds of the study area in the braided river delta:small-scale marine flooding,embankment,and progradation;the interbeds can therefore be divided into three grades to meet the production demand.Based on this classification scheme,the spatial distribution characteristics of different grades and contributing factors were determined using the plan-view and cross-section association and seismic attribute data as control for the sedimentary facies distribution.The spatial distribution characteristics of the interbeds influenced by different factors were characterized and predicted based on the combination of deterministic and stochastic models.