Study On The Reservoir Architecture Of The Neogene IV-V Oil Group In The Footwall Of The No. 2 Fault In Gaskule Oilfield

With the old area of domestic oilfield in the field of water injection mostly enter the later stage,the distribution and understanding of the large-scale contiguous sand bodies cannot solve the contradiction between the injection and the production in the current stage of the oilfield,therefore,the requirements for the fineness of the reservoir description are getting higher and higher.Under the background of such demand,for the ?-? reservoir group of the lower plate of N1-N21 reservoir in Gaskule oilfield,the three aspects of the small-layer sequence framework,sedimentary microfacies distribution and internal reservoir configuration are re-examined and described.Taking the small layer as the basic Stratigraphic unit,the Y58 well with rock core data and obvious well logging response is selected as the standard well,the small layer comparison network with 33 lines was established according to the direction of the vertical source and the direction of the parallel source.The Logo layer method is the main division method and is supplemented by the Equal elevation method and the Slice method,divided 623 wells into 50 small layers in the work area?Through the summarization and summary of previous studies,it is clear that the N1-N21 reservoir in the Gaskule oilfield is a set of main development lakes,braided river deltas,and braided river sedimentary systems.By analyzing the petrological characteristics,sedimentary tectonic markings and particle size distribution characteristics of the core of the target layer and combining the logging phase markers to the sedimentary facies of the target layer,determining the work area as the sub-phase of the dialected river delta,with underwater distributary channel microfacies,estuary dam microfacies,mat sand microfacies,subaqueous interdistributary area microfacies.Through the analysis of single well phase,the relative ratio of wells,and the planar distribution of sedimentary microfacies,the distribution scale and morphological characteristics of sedimentary microfacies in the horizontal and vertical directions are fully understood,and the characteristics of sedimentary microfacies vertical evolution of the ?-? reservoir group in the lower part of the study area also be described.Finally,the sedimentary facies model of the IV-V reservoir group in the lower part of the Gaskule oilfield was established.According to the Miall configuration interface grading and lithofacies type division method,under the control of the 5-level interface,according to the overlapping relationship between the sand bodies separated by the 4-level interface and the splicing relationship between the sand bodies under the 5-level interface control The interior of the sand body is divided into configuration units.The rock facies division is carried out inside the configuration unit,and 21 types of facies are summarized.According to the different splicing methods in the vertical and vertical directions,11 kinds of configuration unit splicing methods are divided.Finally,the reservoir configuration pattern is drawn.Explain the five configuration patterns.The results of this study can provide reference for the prediction of favorable oil blocks in the old oilfields,and help to reduce the cost of development wells and improve the efficiency of harvesting.