| Wenmingzhai oilfield is located in shen county of liaocheng city in shandong province with qingfengxian interchange of puyang city, henan province, oil bearing area of 8.7km2, oil geological reserves of 2234.47×104t, oil-bearing horizon of paleogene shahejie formation sand a to four, reservoir buried depth of 1360-2320 meters, with the well segments for an average of 960 meters. The oilfield is atypical complex fault block oil fields, through more than 30 years of development, the overall water flooding development effect is good, but with the improvement of degree of oilfield development, oil accumulation appeared many problems, such as depositional systems complex, reservoir changes quickly, reservoir heterogeneity is serious, remaining oil is highly fragmented, understanding is difficult, and so on. In order to solve the problems we are facing, further improve the development effect, in this paper, on the basis of the research of sedimentary microfacies of reservoir characteristics and distribution of sand body to do a thorough analysis and characterization, looking for remaining oil provides a reliable geological basis for later.Based on sedimentology, reservoir geology, logging geology, comprehensive utilization of fine reservoir description technology, multidisciplinary combination of technology and system analysis technology, adopts the research method of multi-factor comprehensive analysis by using drilling, logging data and logging data, through the analysis of scanning electron microscopy (sem) images, the casting thin sections, core analysis data, etc, further study of reservoir petrology characteristics, physical characteristics and heterogeneity characteristics, sums up the study area reservoir heterogeneity characteristics on the transverse and longitudinal distribution, identified the isolate interlining interlining and analyzed the distribution characteristics. The reservoir heterogeneity in the studied area the main influence factors of comprehensive research, thus to improve the ultimate recovery in oilfield and improve development effect laid the foundation of geology.According to core observation, casting thin sections identification and sem image analysis, we can see the Lower 2ndand the Upper 3rd sandstone reservoir are mainly composed of arkose, lithic arkose, the Lower 2nd reservoir porosity is 26.81% on average, the average permeability is 207×10-3um2. The average porosity of the Upper 3rd sandstone reservoir is 25.61%, the average permeability is 396.25×10-3um, both of the two members have medium-high porosity and permeability. Controlled by the sedimentary microfacies in the delta front end, the Lower 2nd and the Upper 3rd is strong reservoir heterogeneity, especially the intraformational heterogeneity and plane heterogeneity is serious. Lithology and physical properties on the vertical facies are mainly characterized by complex rhythms, porosity and permeability in the plane of strong heterogeneity, the permeability variation coefficient of more thanl. Thickness of reservoir interlayer very development, generally larger, distribution range is wide, main development are lithologic interlayer and the property of two kinds of interlayer. Effective reservoir is mainly distributed in the underwater distributary channel, frontal sheet sand, but the effective thickness coefficient significantly smaller. After in-depth analysis of the influence factors of reservoir heterogeneity, it is concluded that the heterogeneity of the reservoir are influenced by many factors, one of the most important is the sedimentary characteristics, diagenesis and tectonism, and later period of waterflooding on reservoir sand bodies on the lateral and longitudinal control, through the change of macroscopic and microscopic reservoir structure, make the area of the reservoir heterogeneity is strong. |
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