松辽盆地古龙凹陷姚家组震积岩研究

Study of Yaojia Seismite in Gulong Sag of Songliao Basin

通过岩心观察和描述,结合构造背景研究,在松辽盆地古龙凹陷白垩系姚家组中识别出震积岩并建立了该地区的震积序列。震积岩的主要标志有液化砂岩脉、震裂缝、微断层、不协调岩块、重荷模、似眼球状构造等。震积岩的发现有助于分析研究区的沉积环境、构造演化等。地震活动对油气成藏有很大的影响:地震活动降低储集层的孔渗参数,造成一些固结致密岩石的破裂,既能提高储集性能,又能破坏盖层;因地震作用形成的垂向砂岩岩脉、小型断裂和裂缝深刻影响和改造了储集层和盖层的渗透率,从而影响了油气的运移和聚集。

Based on the cores observation and description as well as the geological setting research, the seismite is identified in the Yaojia formation of Cretaceous in Gulong sag of Songliao basin, and the seismite sequence in this area is established. The seismite is characterized by such marks as liquefied sandstone dikes, seismic fissures, micro-faults, discordant blocks, load casts, eye-like structures, etc. The dis- covery of seismite is helpful to analyze the sedimentary environment and structural evolution in this area, and the seismic activity has a sig- nificant effect on hydrocarbon accumulation. It can reduce the porosity and permeability of reservoirs, cause rupture of some consolidated or tight rocks; it can destroy the cap rocks and improve the reservoir quality; the permeability of reservoir and cap rocks can be greatly ef- fected by the vertical sandstone dikes, micro-faults and fissures caused by seismic actions, accordingly, the oil and gas migration and accu- mulation could be effected by them..