关键词: 松辽盆地, 葡西地区, 葡萄花油层, 断层垂向封闭性, 构造发育史

Abstract:

On the basis of studying fault characteristics and structure development history of Putaohua reservoir in west Putaohua Oilfield and calculating the content of shale in fault-plane zone and the parameters of normal stress on fault surface, which controls the vertical sealing capability, this paper evaluated the vertical sealing properties of 7 major faults in four periods and briefly discussed the relation between fault sealing and its evolution history and hydrocarbon migration, accumulation and reservoir formation. Four periods including the end of the Yaojia Formation deposition, the end of the second member of  Nenjiang   Formation deposition, the end of the third member of  Nenjiang Formation deposition and the present were investigated. The results showed that:(1)Faults had poor vertical sealing capability at the end of the Yaojia Formation deposition;(2)The vertical sealing capabilities  of  No.4 and No.5 faults remained relatively poor but others were good at the end of the  second  member of Nenjiang Formation deposition;(3)Faults had strong vertical sealing properties from the the end of the third  member  of Nenjiang Formation deposition to the present. Generally, the NNW-trending faults had nice vertical sealing properties and were favorable for oil-gas accumulation in Putaohua reservoir; And the NNE-trending faults had a comparatively long open period and could act as main hydrocarbon migration passages for the source rock in Qingshankou Formation.

Key words: Songliao Basin, west Putaohua Oilfield, Putaohua reservoir, vertical sealing property of fault, structure development history