| Most oil fields in China are continental deposits. The reservoirs are heterogeneous and lack of natural energy. So they are exploited mainly by water injection and extraction. China is the world's highest proportion of water injection wells and the reserves of water injection wells is more than 85% of total reserves. Since the last decade, no major new oil field has been discovered. Stable development of crude oil is largely dependent on controlling water, stabilizing the oil and comprehensive measure such as tapping the potential. Most oil fields have entered the high-water stage whether from the water composition in oil extraction wells, or from the oil production constitutes.After 90 years of the 20th century, the fields according to their characteristics, have carried out studies on mechanisms of flooding, and get some new knowledge. Yi-Ren Fan extended non-symmetrical"U"curve to"U","S","L"3 patterns because the injected water salinity is different. Later, with the updated experimental apparatus and perfect experimental methods, a number of new projects are carried out, such as the induced polarization potential experiments, membrane potential experiments, the experiments of dispersion characteristics for rock resistivity. They provide some help to water-flooded mechanism and the practical interpretation of the water-flooded layer.There are some inconsistencies in laboratory, theoretical simulation and practical application of water-flooded layer log evaluation. Yang Jingjiang, etc. focus on the mechanism of water-flooded in Daqing oil field and the current flooding logging prominent issues in theoretical thinking and analysis in order to make further explanation on the conflicts of water-flooded mechanism and practical application. In the experiment of water-flooded mechanism, the author explicated the S change regularity of the resistivity of core in the course of fresh water displacement process, through the analysis of different contributions of connate water and injected water. After multidisciplinary analysis on the regulation of water-flooded mechanism, sealed core data analysis and practical electrical logging data, the author concluded that the resistivity of water-flooded layer presents the tendency of declination in Daqing Lasaxing oilfield under the current condition of produced water re-injection. Through core data statistics of the declination rules of chlorate at different water flushed levels, the author summed up influential factors on the resistivity variance of water-flooded layers in water-flooded fields, and pointed it out that the dissolution of mixed fluid to chlorate should not be overlooked. The main factor which causes reservoir resistivity high or low is different of accumulation dynamics condition, which also is the main reason causing distribution of irreducible water in different pore tupes.Under the similar condition of reservoir physical property, the reservoir resistivity declines graduslly with the increasing of irreducible water saturation. The microcosmic displacement mechanism of water wet rock can be considered as the reverse process of reservoir accumulation. The law of water-drive electric property can be got from the changes of the resistivity rate in rock electrical parameters experiments. In macro level, water cut plot of reservoir with good physical property presents the characteristic of slowly rising period, while that of poor reservoir shows steep rise.Some layers of Chaoyanggou and Toutai oilfields, east of Daqing Placanticline, have been flooded since they were exploited by water injection in 1986. The moisture content is 55% (the main block of oil field exploitation). However, there is still residual oil because of the inequality between the injection and extraction, large interlayer interference and the inefficient exploitation. Therefore the research on east oilfield interpretation measure to evaluate residual oil appropriately is very important. At present these areas of low reservoir porosity, low permeability, low oil saturation, high irreducible water saturation, have low oil resistivity. Water-flooded layer can not be identified easily because the resistivity dose not descend obviously after flooded and the calcic layer results in high resistivity. The fissure existing in reservoir can make water-flooded suddently. For these reasons, causing the perforation of wells in the encryption, mistakenly flooded when the reservoir level to open fire, killing all wells with high water content (oilfield production in 2001, 30 wells, 5 wells with high water content; the first oil field in Taiwan 2002, 11 production wells, 3 wells with high water content). The eastern oil fields account for 60-70% of the external field, thus the output of eastern oil fields in the periphery play a vital role. However, the first station, there is no flooding oilfield Logging interpretation, and thus according to the field lithology, physical characteristics of a developed oil field flooded layer adapted to the log interpretation method for the preparation of programs to provide accurate perforation basic information to meet the needs of oil field development and production, very necessary.Fuyu layer is the main layer of Chaoyanggou and Toutai oilfields which have low permeability.The sedimentary environment is mainly fluvial, delta plain facies and shallow lake facies. The development consists of fluvial sand body, delta distributary channel sand plain sand, underwater distributary channel and delta front sheet sand. The layer mostly has siltstone and fine sandstone which is slim granule and has high mud content. The composition of the minerals is feldspar, debris and quartz. The large proportion is feldspar and debris. The layer has low maturity. Feldspar is soluble, easily broken by mechanical compaction and filling with the pores of sandstone, but also easy to be dissolved to form a porous, elastic easy to press, easy deformation, easily compacted into a dense rock that decrease the rock's permeability. Due to the lithology, sedimentary facies, micro-structure and control of faults and other factors, Chaoyanggou and Toutai oilfields are low-permeability oil fields lithology, lithologic - structural reservoir. The relationship between oil and water is complex. The mechanism and washing conditions are more complex after water injection and water-flooded. It is difficult to interpretate the grade of water-flooded layer.This paper studies of the the logging theory of water-flooded layer based on the use of domestic logging data, according to the external Chaoyanggou, Toutai Oilfield which has low porosity, low permeability, high clay, high calcium, high bound water, low oil saturation and other geological paper proposes the use of log interpretation methods of identification of flooded layer. It proposes the interpretation methods of identification flooded layer and establishes water-flooded platform of quantitative interpretation chart of Chaoyanggou and Toutai oilfields by using logging curves. It also carrys on core experiment about the reservoir rock wettability and relative permeability and establishes methods to determine reservoir wettability and relative permeability by using logging data. Composite water-flooded interpretation method is established by using logging parameters and the compliance rate of interpretation is 83% or more. It will provide a reference for encrypting well programs and preparation programs reasonably in the external Changyuan of Daqing oil field in the future.
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