The Source To Sink Analysis Of The 1st And 2nd Member Of Shahejie Formation Of The Paleogene Of Lixian Slope Of Raoyang Sag

Lixian Slope of Raoyang Sag is a northeastward inherited large sedimentary slope.It has a large amount of residual hydrocarbon resources.It is the main battlefield for increasing reserves and production in Huabei Oilfield.The results show that the stratigraphic framework of study section is clear.The 1st and 2nd member of Shahejie Formation is divided into two third-order sequences.The main reservoirs is the 1st member of the Shahejie Formation.It is furtherly divided into five sand groups: SQw,SQt,SQs III,SQs II and SQs I.By using the theories of sequence stratigraphy,sedimentary petrology,and seismic sedimentology,under the control of the stratigraphic framework,using the method of composition maturity,heavy mineral type,ZTR index and zircon U-Pb dating to indicate the sediment provenance of the Shahejie Formation.Studies have shown that during the Shahejie Formation has three sediment sources that originated from southwest,west and northwest direction,corresponding to the ancient Dasha River,ancient Tang River and ancient Daqing River.It is identified that the shallow water delta facies and the lacustrine facies mainly developed in the 1st and 2nd member of the Shahejie Formation in the study area by using the core facies and logging.Seismic slices were used to describe the sediment distribution,and the sedimentary characteristics and evolution laws of the shallow water delta and lacustrine facies in the 1st and 2nd member of Shahejie Formation were analyzed in details.The amplitude boundaries of the different facies of the shallow water delta can be seen on the stratigraphic slices.Among them,the hydrodynamic conditions of the 2nd member of the Shahejie Formation are weak.Until the special lithology section of the 1st member,the lake basin expands and the waterdeepens rapidly.The water in the upper part of the 1st member of Shahejie Formation is shallower,and the source in the southwest is gradually increasing.The sedimentary range of the shallow water delta gradually increases toward northeast.By analyzing the source system,the transport system and the sedimentary system,it is believed that S2 S of the regional provenance-gentle slope-braided river delta and the Beach-bar Sandbodies are two major types in the study area.What's more,the shallow-water delta front of the Lixian slope has been proposed as a favorable zone.