The Study On The Development Characteristic Of Unconformity And Its Effect On The Migration And Accumulation Of Hydrocarbon

Unconformity, which is one of the most common geological phenomenons, has a very close relationship to the migration and accumulation of hydrocarbon. The structural feature of unconformity is analyzed through the research of evolution feature of unconformity. Thereby the important role of unconformity in the migration and accumulation of hydrocarbon is revealed. And according to this, we can further guide the exploration of concrete area.According to the origin mechanism and controlling factors of unconformity, unconformity can be divided to seven types: truncation unconformity, fold unconformities, diapirsm unconformities, Seismo- unconformities, palaeokarst unconformities and overlap unconformity. These types can be subdivided to thirteen subtypes. The new division absorbs the most advanced development and excludes the repeated methods in order to make the division plan more reasonable. In the each working area, unconformities are identified using seismic methodology and distribution map of unconformities'type was charted. The result indicates that the distribution pattern of unconformity has four features: difference, order structure,fold and migration. The shapes of unconformities are also controlled by the structure of the basin. Unconformities in the eastern basins have some difference to that in the western basins. The seismic features also have some difference.layer structure existed in the unconformities. Lithological patterns of the unconformities are researched by the well core observation, logging identification and elemental analysis. Eight types of unconformities was identified from Neogene to Paleogene in Huimin Depression, and three types of five subtypes unconformities was identified in Wuxia Area with Jungar Basin. Different types of logging reflection were carefully analyzed and the mechanism of the same type of unconformity is concluded. Through the elemental analysis, microscope and scanning electron microscope observation, eluviation has a significant meaning to the reforming of the physical characters.Geological model of unconformities'transportation system is built, mechanism of hydrocarbon in the unconformities is analyzed and concavo-convex vergent (aggregate and divergence) of hydrocarbon migration within the unconformities is proposed, which effectively guided the research of accumulation rule and exploration in Huimin Depression. Integral fuzzy judgment is applied to semi-quantity method research the transportation ability of unconformities in Wuxia Area in Jungar basin. Unconformities in the bottom of T1b in Wu 29 well area were proposed as the next target for exploration.Accumulation rule of hydrocarbon in the unconformities is researched. Distribution of unconformities makes hydrocarbon displayed as the shape of banded area; Unconformities provided the excellent reservoir shape; Unconformities play a very important role in sealing capacity, communication in migration, self-accumulation and destroy-construct. Unconformity hydrocarbon accumulation is influenced by many factors; Unconformities can indicate the accumulation of hydrocarbon.