Research On The Relationship Between Time And Space And Their Controlling Functions Of Source,Reservoir And Caprock Of The Middle And Shallow Gas Layer In Nanpu Depression

The shallow layer is an important layer of natural gas exploration in Nanpu depression.In order to study the law of natural gas distribution and guide its natural gas exploration,based on the study of source rock development and hydrocarbon generation and expulsion evolution characteristics and transporting faults distribution and activity characteristics and cover layer development and closure of evolution characteristics,the time and space matching relation of source,fault and caprock is divided into the time and space matching relation of source and fault and time and space matching relation of caprock and fault.After the two,the former is studied.Based on the distribution of natural gas,the control effect of gas accumulation and distribution in the middle shallow layer was studied.The results show that the space matching relation of source and fault of the shallow middle shallow layer of Nanpu depression is mainly distributed in the center of the depression,the area is smaller.Better space matching relation area of source and fault is distributed in the surrounding area,the area is relatively larger.Outside medium source fault space matching relation area is the inferior spatial matching relationship of source and fault zone.Space matching relation of fault and caprock in middle shallow layer is Ed3 and Ed2 better,Edl and Ng4 is worse.Sealing area of Ed3 fault and caprock matching area distribute both in the west and east of the depression.Sealing area of Ed2 fault and caprock matching area distribute most in the west of depression,the south and east are little.Sealing area of Edl and Ng4 fault and caprock matching area distribute most in the west south of depression.The rule of middle shallow layer source rock fracture cover spatial matching relation is poor,the best area only in Ed3 and Ed2,the area is small,Edl don't have the best area.The better area locate among the best area.The medium area mainly located in the west and middle of the depression,the area is bigger,Es3 also have some area in the east of the depression.The large area is poor area in the depression.The time matching of source and fault of Edl is the best,which is conducive to the migration of natural gas.The second is Nm—Quaternary,the Es3—Es2 is the worst.The time matching of caprock and fault of Nm—Quaternary is the best,which is conducive to the migration of natural gas.The other two sedimentary periods is not good,which is not conducive to the closure of natural gas.The time matching of source fault and caprock of Nm—Quaternary is also the best,which is conducive to the migration of natural gas.The other two sedimentary periods is not good,which is not conducive to the closure of natural gas.The control effect of the time and space matching relation of the medium and shallow source fault and caprock gas accumulation and distribution is mainly shown in 2 aspects:?The space matching relation controls the favorable position of natural gas accumulation.Laoyemiao,No.2,No.5,No.1 are favorable for the accumulation and distribution of natural gas in the middle and shallow layers.? The time matching controls the number of natural gas reservoirs.Nm—Quaternary sediments period is more conducive to the accumulation of natural gas in the middle and shallow layers.But,as a result of the time matching relations of source fault and caprock in middle shallow layer in Nanpu depression is relatively poor,it is not conducive to large-scale natural gas accumulation and distribution,which may be the cause of although there are gas found in Nanpu depression in middle shallow layer,but quantity,the quantity and scale are limited.The favorable areas of natural gas accumulation are mainly in Laoyemiao,No.5 and No.1 structure of Ed3 in Nanpu Sag.The favorable areas of natural gas accumulation are mainly in No.5 and No.1 structure of Ed2 in Nanpu Sag.The favorable areas of natural gas accumulation are mainly in No.1 structure of Ed3-Ng4 in Nanpu Sag.