Diversities Of Structure And The Hydrocarbon Pool Forming Conditions In The East Of Linqing Depression

In the eastern part of the Linqing depression, there is more complex structural setting and lower exploration degree than that in other depressions in Bohai Bay basin. Therefor, it lead to many problems unresolved such as structural feature, the type of oil-gas reservoir, the main controlling factors of hydrocarbon accumulation. This paper attempts to address these issues carried out from the basic seimic interpretation. Though the division of the structural layer and the determination of tectonic evolution, it could to be identified the main structural forms and analysised which structural form is to controle the hydrocarbon accumulation in various geological units in the Linqing depression. Accordingly, combinating with the study of the drilled wells, it try to find out the hydrocarbon reservoir distribution and the accumulation factors for the nonhydrocarbon gas,coal-derived gas and immature oil. If these series work can provide useful guidance for future oil-gas exploration in this region, it would be my great pleasure.The main contents of this paper include the following aspects. Firstly, complete the division of the structural layer in the seismic profile Secondly, summarizing the structural evolution history, it is characterized by compression, uplift and redeposition movement alternately. As the imbalance effect in polyphasic orogenic cycle, the early formation listric faults change into half-graben. The later sustained slip make the Cenozoic structure develop srike-slip fault. Therefore, the main structural styles is extend,compression, slip structural and tilted block in the easten part of Linqing depression. Among these structural styles, extend and slip ones are the majority.Different faults combination form different types of traps reservoir. Furthermore, hydrocarbon resource is closely linked to the geloogical setting in this region. It is proved that detachment fault and structural transformation belt greatly affect the accumulation of nonhydrocarbon. The later sustained-activity fault in deep layer could contact the relationship of the source and reservoir. Therefore, such the hydrocarbon reservoir has been explored in shallow layer. Hence, the oil-gas derived of the coal can not be limited to the extend geological setting of near-source slope or sag. It should be positively explored in such zone as the compression background of the decken structure and later-activity fault. Tertiary immature oil does not have the large-scale possibility of hydrocarbon reservoir, while the potential orientation is the lithologic trap and low altitude difference structural trap in the edge of the sag.