【摘要】 永新地区油气藏类型属于复杂断块油气藏,具有构造复杂、储层类型多样、含油气层系丰富的特点,该区地震勘探存在的主要问题是低序级断层成像精度不高。为解决低序级断层的成像问题,在该区部署了高精度地震采集,包括以下技术环节:①观测系统设计,设计了面元细分的高精度采集观测系统,该观测系统具有密度高、空间采样均匀、覆盖次数高、道数多的特点;②近地表结构调查,采用表层取心、小折射、单井微测井、双井微测井、地质雷达等近地表结构调查方法,确定了低降速带的厚度、速度、岩性等,建立了工区高速层等厚图,为激发条件选择提供了依据;③接收技术,组合检波选择的主要参数包括组内距、组合基距、组合图形、连接方式;④激发技术,激发技术重点体现在激发井深控制、高程控制、激发药量控制等方面。通过高精度地震采集获得的单炮记录整体信噪比很高,剖面的断层成像质量及信噪比更高,面元越小分辨地质体的能力越强,横向偏移归位精度也越高。更多还原

【Abstract】 The reservoir type in Yongxing area belongs to complex fault-block reservoir, which is characterized by complex structure, multiple reservoir types and abundant oil/gas-bearing bed set. The main problem of seismic exploration in the area is lower imaging precision of low-sequence faults. In order to solve this problem, the high-precision seismic acquisition was deployed in the area, including following technical links: ①geometry design, designing bin size-fractionized high-precision acquisition geometry that is characters of high density, uniform spatial acquisition, high folds and multiple channels; ②near-surface structure survey, adopting near-surface structure surveying methods such as near-surface coring, shallow refraction, uphole survey of single hole, uphole survey of double holes and geologic radar et al, which determined the thickness, velocity and lithology of weathered and sub-weathered zone, created isopachous map of high-velocity layer in the area, providing foundation for selection of shooting conditions; ③receiving techniques, the main parameters selected in geophone array are geophone interval,group interval,array pattern and connecting pattern;④shooting techniques, which highlights the control of shooting-hole depth, elevation control and shooting charge size control. The total S/N ratio of single-shot record acquired by high-precision seismic acquisition is very high, the imaging quality and S/N ratio of fault on the section are very high; the smaller the bin size, the higher the resolution of geologic body, and the higher the precision of positioning of lateral migration as well.更多还原