摘要:
通过野外露头、钻井岩心、测井曲线和地震资料的综合分析,在识别出 4类不同成因类型和规模的层序界面基础上,将百色盆地那读组划分为 1个超长期、5个长期和 16个中期基准面旋回层序。并详细地讨论了层序与生储盖组合的关系,指出生储盖组合特征与长期基准面旋回关系最为密切,有利储层发育位置主要出现在长期基准面上升半旋回的早中期和下降半旋回的中晚期,转换面附近则是烃源岩和盖层的发育位置;各长期旋回层序的生储盖组合具不同特征,明显受基准面升降幅度、频率及其所影响的相组合、可容纳空间和A/S值变化控制;按生储盖组合在垂向和纵向上的配置关系,可划分为上生下储、下生上储、侧向运移等 3种基本组合类型。
Abstract:
Through the comprehensive analysis of out crop, rock cores, well loggings and seismic data, one super-long-term, five long-term and sixteen middle-term base-level cycle sequences are distinguished in Nadu Formation of Baise basin. In this paper, the relationship between the source-reservoir-cap associations and the base-level cycle sequences of Nadu Formation are discussed in detail, and some knowledge is acquired as follows: (1) long-term base-level cycles bear close relation to source-reservoir-cap rock associtations,the main reservoir sand bodies develop in the early-middle stage of the uprising periods and middle-late stage of subsiding periods of the long-term base-level cycle, and the main hydrocarbon source rocks and favourable regional cap rocks develop at the turning position from uprising to subsiding of the long-term base-level cylce; (2) the characteristics of source-reservoir-cap rock associations developed in each long-term base-level cycle are distinctly different and controlled by the frequency, amplitude of the rising and falling of the base-level, facies association, accommodation and A/S ratio; (3) according to the spatial relationship of source rocks, reservoir rocks and cap rocks in the vertical or horizontal section of the formation, three types of basic associations can be divided. The first associations is usually of the type with source rocks in the upper and reservoirs below, the second one with source rocks below and reservoirs in the upper, and the third one with source rocks in other district.