Study On The Barriers And Baffles Of Guantao Formation In Ban64 Fault Block Of Banqiao Oilfield

The Guantao Formation in Ban64 fault block of Banqiao Oilfield is a typical set of braided river deposits.The braided river channel in the study area moves and swings more frequently,which makes the distribution law of interlayer in three-dimensional space complicated,thus affecting the development effect of Guantao Formation reservoirs in Banqiao Oilfield.In order to effectively solve the problems existing in the current development of Banqiao Oilfield,this paper conducts detailed research on the interlayer of the reservoir in Guan-Ⅲ Formation of Ban64 fault block.Based on the study of the fine stratigraphic framework and sedimentary microfacies,this paper identifies different types of interlayers and their genetic mechanisms,dissects the distribution characteristics of the interlayer from a multidimensional perspective,and establishes a three-dimensional geological model of the interlayer in the study area.This has laid a necessary geological foundation for the efficient development of the oil field in the later stage.The research results indicate that the Guan-Ⅲ Formation of Block Ban 64 can be vertically divided into 4 small layers and 6 single layers.The target layer is braided river sediment developed from NNE to SSW in the provenance direction,mainly developing three sedimentary microfacies of braided channel,central beach bar,flood plain,and two sedimentary microfacies composite pattern.The Guan-Ⅲ Formation in Ban 64 fault block mainly develops muddy and physical interbeds,and the main genetic mechanism is sedimentation,including flood plain mudstone deposition,argillaceous filling of gullies on the top of the central beach bar,argillaceous deposition of abandoned river channels,tribal siltation deposits in the central beach bar,and relatively coarse sediments of braided river channels and the bottom of the central beach bar.Among them,the mudstones in flood plain are the most stable and widely distributed,which can almost cover the whole study area and are good barrier deposits;Gully mud filling is mostly the product of changes in water flow energy,with the most scattered distribution,mostly located at the top of the central beach dam,extending in a narrow strip shape;The argillaceous deposition of abandoned river channel is similar to that of gully,which is generally located on the side of braided river channel near the concave bank,and is distributed in a crescent shape;The distribution of sediment deposition layer interlayers is relatively scattered,all developed within the core beach dam,with a shorter lateral extension and smaller sedimentary thickness,making them the main interlayers in the study area;The interlayer at the bottom of braided channel and central beach dam is mostly physical interlayer,which is the product of flooding scouring sand bodies.Most of them are sandy conglomerate or pebbly sandstone.Their distribution in the study area is relatively limited,and their barrier effect on underground fluids is weak.The three-dimensional model of interlayer obtained through the combination of deterministic modeling and artificial interaction modeling method has a relatively stable distribution of barriers,and baffles are mostly concentrated in the areas where the central beach dam or abandoned river channel is more developed.The development location and distribution scale of the interlayer are all factors that affect the distribution pattern of residual oil in the reservoir and have a strong control effect on the distribution of remaining oil.