刚果扇A区块中新统层序地层与沉积相研究

发布时间：2018-11-27 19:07

【摘要】：刚果扇A区块中新统油气藏面临储层分布和剩余油分布难题,前期认识和研究成果存在一些问题,包括高精度层序地层格架的建立;重力流水道成因类型与结构;水道期次的划分与砂体平面分布的精细刻画等。论文以高分辨率层序地层学和深水沉积理论为指导,通过对深海扇多级次层序界面的识别以及重点水道期次的划分,建立高精度层序地层格架。重力流成因旋回(短期旋回)主要表现为水道早期侵蚀下切,中期辫状河曲流形态沉积,晚期朵叶体形态废弃静止的发育过程,其对应单期扇体的向上变细特征或扇体退积特征。异旋回(长期旋回)由不同叠加样式的多期单一成因旋回组成,并表现为多期单一成因旋回扇体进积或退积特征。重力流水道成因旋回界面识别与划分依据,包括重力流水道底部侵蚀冲刷面,水道顶部稳定连续深海泥岩段,以及扇体不同级别和期次的扇体进退积转换面。论文以高频旋回时间格架约束,以地质模式为指导,地质与地球物理技术相结合,分析浊积水道储集体分布规律,精细刻画了水道沉积体的平面迁移和内部充填特征,水道的内部充填演化主要经历初期侵蚀、侵蚀—充填、加积充填和废弃这四个阶段。深海扇内部垂向不同时期,平面不同位置,其重力流水道发育类型多样,主要有下切沟谷,侵蚀水道,叠置复合水道,迁移水道和孤立水道。通过拟声波阻抗反演技术,清晰揭示了不同重力流水道富砂储层分布位置及特征,富砂储层主要富集于叠置复合水道和迁移水道的上部,以及孤立水道两侧天然堤内部和朵叶体中部。
[Abstract]:The Miocene oil and gas reservoirs in block A of Congo Fan are faced with difficulties of reservoir distribution and residual oil distribution. There are some problems in early understanding and research achievements, including the establishment of high-precision sequence stratigraphic framework, the genetic types and structure of gravity flow channel, and the distribution of residual oil and gas. The division of watercourse stages and fine characterization of sand body plane distribution. Under the guidance of high-resolution sequence stratigraphy and deep-water sedimentation theory, the high-precision sequence stratigraphic framework is established by identifying the multi-level sub-sequence interface of deep-sea fan and dividing the key watercourse stages. The genetic cycle of gravity flow (short term cycle) is mainly characterized by the early erosion of the watercourse, the deposition of the braided river meandering flow in the middle period, and the abandoned and stationary development process of the late flower leaf body shape. It corresponds to the upward thinning or regressive characteristics of the single phase fan. The metacyclic (long term cycle) is composed of multiphase single genetic cycles with different superposition styles, and it is characterized by multiphase single genetic cycle fan progradation or retrogradation. The genetic cycle interface of gravity channel is identified and classified, including erosion and erosion surface at the bottom of gravity channel, stable and continuous deep-sea mudstone section at the top of the channel, and fan forward and backward transition surface at different stages and stages of fan body. Under the constraint of high frequency cyclic time frame, guided by geological model, combining geology with geophysical technology, the distribution law of reservoir body in turbidite channel is analyzed in this paper, and the plane migration and internal filling characteristics of watercourse sedimentary body are described in detail. The internal filling evolution of the watercourse mainly goes through four stages: initial erosion, erosion-filling, accretion filling and abandonment. In different periods of vertical direction and different position of plane in deep sea fan, there are various types of gravity channel in deep sea fan, such as undercut gully, erosion channel, overlay composite channel, migration channel and isolated channel. By means of pseudo acoustic impedance inversion technique, the distribution and characteristics of sand rich reservoirs with different gravity flow paths are clearly revealed. The sand rich reservoirs are mainly concentrated in the upper part of superimposed composite watercourses and migration waterways. And isolated waterways on both sides of the natural embankment and the middle of the flower leaf body.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13;P534.621

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