海拉尔盆地油气成藏特征及分布规律

Hydrocarbon reservoir forming characteristics and distribution rule of Hailar Basin

海拉尔盆地是受北东向断裂控制的复杂断陷 ,内部发育了三套烃源岩地层 ,烃源岩厚度较大 ,有机质含量高 ;发育了背斜型油气藏、断块型油气藏、变质岩潜山油气藏、岩性油气藏。该盆地的油气分布规律为主力生油凹槽的两侧是油气的有利富集带 ,不整合面控制着油气的分布 ,其界面上、下油气最富集 ,控制断陷结构的大断裂 ,特别是凹槽的传递断层带所控制的构造是油气聚集的有利区带。苏德尔特构造带下降盘、贝西斜坡带、巴彦塔拉构造带、乌北洼陷岩性带为最有力的勘探区。

Hailar Basin is a complicated down faulted basin,which interior develops three sets of hydrocarbon source rocks with larger thickness and high content of organic matter. Under the regional cap rock of Damoguaihe Formation,many sets of source-reservoir-cap rock association are developed. Reservoir type mainly consists of basement rock weathering crust and fractures,Xinganling group tuff, tuffaceous sandy-conglomeratic reservoir,Tongbomiao Formation conglomerate,South No.1 member sandy-conglomerate,South No.2 member siltstone-fine sandstone,clastic rock reservoirs.Anticlinal oil and gas reservoirs, fault block oil and gas reservoirs, metamorphic clastic rock buried hill reservoirs,lithologic reservoirs are developed.The oil and gas distribution rule is two flanks of the main oil gereration depression are a oil and gas favourable abundance zone and oil and gas distribution is controlled by unconformity surface.The most enrichment zone is above and under the surface.Major fracture,controlling faulted structure,especially the structure controlled by transmission faulted zone of the depression is the favourable area and belt of oil and gas accumulation. Lowstand fan and lowstand wedge formed in the lowstand system tract and fan deltaic sand body deposited in the highstand system tract are oil and gas enrichment areas. Downthrow blocks of Sudeerter structural belt,Beixi slope belt,Bayantara structural belt,Wubei depression lithologic belt are the favourable exploration areas.