Time And Space Matching Relation Among Source Rocks-pathway System-traps And The Function Of Accumulation Controlling In Yilunpu Region In Jizhong Depression

The two main sets of source rocks are the Sha3 formation and Sha1 formation in yilunpu in Jizhong depression.Reservoir develops in all formations of the shahejie.It is a typical source-reservoir-cap form named lower source-upper reservoir.The pathway system is a necessary way to transport oil and gas and it is a bridge connecting accumulation elements such as source rock and trap.The drilling data in the study area reveals that oil and gas reservoirs which have been found are all associated with pathway system.But not all the traps which are associated with pathway system have been found oil and gas in them.In order to explore the special distribution law of oil and gas in the study area.We combined with matching relation in time and space and characteristics of the 3 accumulation elements analysis.Using geological data,seismic interpretation,geochemical data,drilling,logging,combined with the results of previous studies,through structural analysis,sedimentation analysis,laboratory analysis and other means to study accumulation elements such as source rock,pathway system and trap.The results show that the two main sets of source rocks are the Sha3 formation and Sha1 formation in yilunpu in Hebei central depression.Reservoir develops in all formations of the shahejie.The cap rocks are 3 sets.Two types of pathway system are fault connecting source rock and reservoir,both faults and sand bodies connecting source rock and reservoir.Traps mainly develop broken noses and fault block traps.On the basis of study 3 accumulation elements,find the matching relationship of hydrocarbon expulsive stage,faults activity stage and formed period of traps.Using seismic interpretation data and many methods such as growth index profile,fault activity rate,Oil and gas migration path,tectonic evolution profile,a profound analysis on the matching relationship in space has been made in the study area.It is concluded that the time matching relationship in Es1,Es2 and Es3 are all good,and advantageous for oil and gas gathering.Good type of space matching relationship distributes in northern study area in Es1.Medium type of space matching relationship distributes in central and southern study area in Es1.The type of space matching relationship in Es2 and Es3 are all medium.Medium type of space matching relationship distributes in northwest study area in Es3.On the basis of space and time matching relationship of the 3 accumulation elements,combined with reservoir types and distribution characteristics of oil and gas.We study time and space matching relation among the 3 accumulation elements and the function of accumulation controlling in Yilunpu region in Hebei central depression.The results show that oil and gas are distributed in the traps of oil-migrating fault as transporting pathway,transporting through fault and sandstone transporting layer as transporting pathway.Matching relationship in space is controlling the position where oil and gas accumulates and the range of oil and gas distribution.Matching relationship in time is controlling the gathering degree of oil and gas.Oil and gas enrichment period are from the end of Dongying formation to the Guantao formation and from the end of Guantao formation to the Minghuazhen formation.On the basis of space and time matching relationship of the 3 accumulation elements,combined with reservoir types and distribution characteristics of oil and gas and time and space matching relation among the 3 accumulation elements and the function of accumulation controlling in Yilunpu region in Hebei central depression.Two hydrocarbon accumulation models are built which is applicable to up reservoir-down source type oil and gas combination.The first model is oil-migrating fault as transporting pathway connecting the source rocks and the traps.The second model is transporting through fault and sandstone transporting layer as transporting pathway connecting the source rocks and the traps.And predict 3 favorable targets in study area.It has a significant sense in recognizing hydrocarbon enrichment rules and in exploring hydrocarbon in up reservoir-down source type field.