渤海海域古近系碎屑岩储层展布定量研究

A quantitative study on distribution of Paleogene clastic reservoir in Bohai water

渤海海域古近系碎屑岩储层主要有2种发育模式,即多套砂泥岩薄互层和大套较厚砂岩。针对多套砂泥岩薄互层储层,以区域沉积体系研究为基础,结合井间储层对比分析,通过地震三维可视化技术重塑古地貌,寻找古沟谷和坡折带,利用"山-沟-坡-面"控砂原理和井约束,可以对储层的空间展布特征进行半定量化研究;针对大套较厚砂岩储层,基于岩石物理综合分析,寻找对储层敏感的弹性参数,利用地震资料,采用叠前同步反演,可以反演出纵波阻抗、横波阻抗、密度等基本弹性参数数据体,然后计算出敏感弹性参数的数据体,进而对储层的空间展布进行精细的定量刻画。这些方法和技术有效刻画了渤海古近系碎屑岩储层空间展布特征,有效避免了储层认识不清给油田储量评价带来的风险,为油田的高效开发生产奠定了基础。

There are two occurrence modes of Palaeogene elastic reservoirs in Bohai water, i. e. multiple thin interbeds of sandstone and mudstone and large sets of thicker sandstone. For the multi ple thin interbeds, the technique of seismic 3-D vi sualization was used to reconstruct： paleo-geomor phology and find out paleochannels, paleovalleys and paleo-slope breaks, on a basis of researching regional sedimentary systems and in combination with interwell reservoir correlation and analysis, and then the reservoir distribution can be semi quantitatively evaluated by using a principle ofsand controlling by ＂ hill-channel-slope surface＂ and the well constraints. For the large sets of thic ker sandstone, it is needed to find out the elastic parameters sensitive to reservoir, based on a de tailed analysis of petrophysics, and the seismic da ta should be used to obtain data volumes of some basic elastic parameters, such as P-wave impe dence, S-wave impedence and density, through a pre-stack simultaneous inversion. Then the data volumes of elastic parameters can be calculated, and the reservoir distribution can be refindedly and quantitatively described. These approaches can ef fectively describe the distribution of Palaeogene clastic reservoirs in Bohai water, avoiding the risk of unclear reservoir in reserves evaluation and lay ing a foundation for efficient development and pro duction of oilfiels.