| The study area located in Tai9 area which belongs to Daqing Oilfield 8th oil mining factory, and its position near the Yongle syncline west wing and located in the northern of Toutai nose structure in the San zhao Depression of Songliao Basin, Since 1979, Putaohua oil-bearing layer, which located in Sanzhao Depression, has had many geological researches in Songfangtun, Shengping, Xujiaweizi, Yongle, Zhaozhou, Weixing and others oil fields. The study area and the surrounding oilfield has many years development, and has been in the middle and later stage which means been in the high water development stage, the remaining oil potential and pressure of reserves replacement is increasing. Therefore, Tai9 area, which located in the outside of Sanzhao depression and is not the main body, becomes the key oilfield development area in the future, but the thickness of formation changes quickly, the forecast of sand bodies has difficulty and oil-water have complex relationships in Tai9 area. It is necessary to establish a high-resolution stratigraphic framework, and have a new recognition for the distribution of sand bodies in Tai9 area. This thesis is based on the core, logging and outcrop data, the full application of the theory of high resolution sequence stratigraphy to analysis of Tai 9 area Putaohua reservoir sequence. First to establish high-resolution isochronous stratigraphic framework, selected yong 120-54 well as the standard well because of it’s vertical good separability and sand body characteristic obvious. Putaohua reservoirs can be divided into 1 formations, 2 sandstones, 7 layers and 11 sedimentary units, and use the area enclosed skeleton section and the short cycle sequence comparison technologies to division and correlation of 268 wells of each time unit, the Putaohua oil reservoir from North West to South East stratum gradually thin. Stratum thickness, sandstone development characteristics and development zone sand body reveal that For the study area source north to south east to west, belongs to the typical off-ramp river source control and shallow water delta front surfaces deposition, resulting in the formation of sand body is small scale, multi style and the poor stability. By analyzing the feature of rock-electricity relation of core well in Putaohua reservoir, establish the electrofacies pattern of 6 sedimentary micro-facies in the front-delta, which are underwater distributary channel, sheet sand, mouth bar, natural barrier, float quick sand and mud between underwater shunt, then construct graphs of sedimentary micro-facies in plane of 11 time units in Putaohua reservoir, recognizing that most of the sand bodies are underwater distributary channel and kinds of sheet sand, and the underwater distributary channel growth in the middle of the reservoir at lowstand, sheet sand growth in the area that reformed by strong wave in southeast. Based on the study on isochronous stratigraphic framework, depositional mcro-facies through-going and oil water distribution law, analysis control oil characteristics of every sedimentary micro-facies sand body in Putaohua reservoir, at last divide 4 patterns on the basis of structural setting, fault segmentation, configuration relationship of fault and sand body: reversal high fault area region where fault and sand body intersection at a high angle, downslope area where fault and sand body intersection at a small angle or parallel, shortness upthrow area where fault and sand body intersection at a middle angle, reversal low fault area region where fault and sand body intersection at a high angle, and then reference matching parameter of control oil factor, finally come up with 14 target area of oil hydrocarbon enrichment. |
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