The Research On The Forming Condition And Distribution Rule Of The Pre-mesozoic Buriedhill Reservoir In The Middle Part Of The Western Slop In The West Sag In Liaohe Depression

Aiming at the state of the buried hill exploration in the west slope of west sag in liaohe depression, this paper studies the basic geological conditions of the pre-mesozoic buried hill in the middle part in the western slop in the west sag by using the theory and the methods such as petroleum geology, structural geology and fine reservoir descriptions. This paper also analyses the forming condition and distribution regularities of the pre-mesozoic buried hill in consideration of the source rocks,reservoir, seal conditions, traps, migration and preservation in order to direct the oil exploration.Absorbing and summing-upon the experience of the predecessor's research production and collecting the data and examples of the internal and international research, the buried hill reservoir has been divided into two kind: massive oil pool and inner layered oil pool by analyzing the features of buried hill oil reservoirs in the middle part in the western slop in the west sag . The distribution of different kinds of buried hill reservoirs has obvious regularities. The study on the forming conditions of oil reservoir shows that the dark mudstone in the fourth member of shahejie formation in the palaeogene provide the good petroleum generation condition, hybrid granite in the archaeozoic erathem carbonatites and quartzite in the neoproterozoic have effective reservoir space after the reforming of later stage, faulting and lithology changing of the inner reservoir of buried hill made the good trap forming condition come into being, the volcanic rock and mudstone with different thickness on the buried hill prevent the dissipating of oil and gas, and the well matched relations of source rocks, reservoir and seal conditions ensured the validity of traps. On analyzing the direction and route of the oil migration in the buried hill, the oil migration mode and rule have been established. In a word, after the strengthen on the basic research and the regularity knowledge, the pre-mesozoic buried hills in the middle part in the western slop have ascendant forming conditions. The reservoirs in buried hills are one of the favorable exploration area in the coming oil exploration, under the condition that the the fourth member of shahejie formation in the palaeogene which overlying the buried hill has been highly prospected.