Research On Hydrocarbon Accumulation Conditions Of The Buried Hill Reservoir In Yanling-Changyangdian Area

Yanling-Changyangdian buried hill located in the north of Raoyang sag is an important play of buried hill exploration.Based on the theory of buried hill exploration and deep study on hydrocarbon accumulation conditions,this paper analized main controlling factors of hydrocarbon accumulation,established hydrocarbon accumulation mode and predicted favorable exploration areas of the buried hill reservoir in Yanling-Changyangdian area.By 3D fine structure interpretation and structure evolution analysis,three types of fault systems were found in Yanling-Changyangdian area,which are early activity type,long-term activity type and mid–late activity type.The buried hill reservoirs are classified into buried-hill head reservoirs,buried-hill slope reservoirs and buried-hill internal reservoirs through early formation,mid burial and later stationary evolution stages.Stratigraphic correlation in buried hill showed that stratigraphic distribution had new northeast,old southwest characteristics.The fault contact and stratigraphic erosion contact formed 5 kinds of reservoir-seal associations.Reservoir comprehensive research shows that the fault phase activity,Maozhou – Renxi trough Es3 and Es4+Ek deep oil and gas resources,Buried hill weathering and insider reservoir properties,third regional caprock sealing ability of buried hill into four elements accumulation dynamic systems.Reservoir and main controlling factors of hydrocarbon accumulation of research shows that the oil source and accumulation of the lateral joint condition is key to deep hill reservoir;North East fault and North West trending faults controlled buried hill high oil and gas enrichment;effective control of buried hill lateral sealing trap;the degree of fracture development and reservoir performance control buried hill oil.According to the construction of the five reservoir models accumulation factors of different combinations,namely "the ancient Wumishan reservoir block" buried hill reservoir model,Wumishan "new reservoir block" buried hill reservoir model,Wumishan "ancient reservoir block" buried hill insider reservoir model and layered reservoir model inside Ordovician mountain wedge type,the Cambrian strata in the buried hill reservoir model.According to the buried hill fault,reservoir,oil source and research achievements in this area of oil and gas enrichment,the main controlling factors of the situation,drilling area of buried hill reservoir was evaluated,it is pointed out that Changyangdian buried hill zone is the favorable area for deepening the weathered crust in buried hill traps and traps inside buried hill,Yanling potential the hillside is a favorable area for the Cambrian wedge buried hill stratigraphic traps.