The Study Of Sedimentary Model Of Reservoir Stratum In West Of North-Ⅱ-East District Of North Saertu Oilfield

West of North-II- East district is located in the East of anticlinal structure of saertu in Daqing placanticline, after the study area entered the development stage of ultra-high water cut stage, with the conditions of water cut increasing and the deepening of oil production, the complicated distribution of remaining oil requires an more accurate knowledge about the reservoir stratum. Due to the notable features of complex injection-production relationship, unclear layer division, the confliction between layers, and the advanced exploitation of Class-I, Class-II reservoir stratum in the study area, the study and development of Class-III reservoir stratum become a top priority. To meet this requirements, this study refines the type of sedimentary microfacies and establishes the logging microfacies model through the study of sedimentary unit subdivision and fine stratum statistics comparison of Class-III reservoir stratum of West of North-II- East district based on the theory of high resolution sequence stratigraphy and fluvial sedimentology, combining microfacies analysis of coring well; then we have a deep acknowledge about the sedimentary environment and vertical evolution law of Class-II reservoir stratum, and can determine the Facies boundary of between the inner and outer Front of Delta, and further establish facies depositional model of Delta front after the detailed study of plain sedimentary microfacies of model combination and recognition of logging facies.In this study, a high resolution of isochronous sequence stratigraphy correlation framework has been established setting all levels of flood surfaces as standard layer, through fine stratum statistics comparison of 65 time units in 1136 wells, the study realizes a unified hierarchical boundaries for each time unit, further refines character of plane distribution in reservoir stratum. After an analogy with sedimentation of Modern Delta and analysis of relationship between lithology and logging, we establish logging facies models of 13 microfacies of the Delta front. After drawing 65 plain microfacies maps of time unit, we also sum up plane sedimentary models of Class-II reservoir stratum in 6 large class and 10 sub class. Then we find large front sand bar sand body in the Delta Outer front facies. According to the deposition environment and distribution features of sand body, we get a new knowledge about the deposition environment of sand body, as well as conduct detailed study of vertical evolution law of Class-II reservoir stratum, such as Saertu I group(G I) is outer front parfacies, G I 2~4+5b is inner front parfacies, P II group is delta inner front parfacies, G I group(G I) 1~9, 11+12~14+15 units are inner front parfacies, G I 10, 16~20 units are outer front parfacies and G II group is outer front parfacies, to establish 6 classes of sedimentary model for sand body of Class III reservoir stratum in research district.