Research Of Sedimentary Microfacies And Watered-out Mode In Wenxi Three Region

After20years of Tuha Oilfield development, the main oil region has entered a period ofhigh water, most of the major reservoirs have been flooded, make field development stable andhigh-yielding more difficult. This discertation is based on the primary core, logging, oil fielddevelopment and flooded layer logging data, focus on water flooded layers evaluation of thelow porosity, low permeability and low salinity reservoirs in Wenxi Three region, researchfavorable sedimentary microfacies, flooded patterns and distribution of remaining oil. In WenXisan block, according to the river flow and lake waves played the dual role of effecting thebraided river delta front underwater distributary channel, estuarine, sheet sand and distal barmicrofacies, structural features and occurrence state of sand, flooding extent and loggingresponse variations during the waterflood development, proposed seven kinds of floodedpatterns of braided river delta front residual oil distribution evaluation. Among them, floodedpatterns of main microfacies including channel single forward-seepage and multiplesuperposed-seepage, which lead to uneven waterline forward, often formed weak floodedlayers and moderate flooded layers located the upper layer or stacked layers; patterns ofnon-main microfacies including sheeted sand seepage and distal bar seepage, which waterlinepropel poor, often formed mild flooded layers or un-flooded layers. They affected theremaining oil distribution and potential tapping parts of utilized and unused oil layers. Specificexamples of the discertation to analyze the flooded logging response characteristics andmodel of interpretation controlled by different sedimentary microfacies, to clarify the maindirection and goals of flooded layers remaining oil potential tapping in this area.