| Most blocks in F oilfields have gone into the production decline stage after tertiary waterflooded adjustment, demonstrating ralatively low recovery. It’s difficult to improve the recovery and maintain the long term steady production only through the water injection. No obvious effects were observed after using different well patterns. In order to explore the new thoughts of secondary developments for F oilfield, XX block was selected as a pilot area.Numerical simulation mdeling method was used to optimize the injection-production parameters related to fine waterflooding and chemical flooding. It’s of significance for the follow-up development of whole oilfield.An investigation of sequence stratigraphy was made in this study. Fine stratigraphic correlation was conducted in the study areas by well and by zone. The stratum had been subdivided into single sand body level. Based on the previous study and available well data,extension of every depositional unit was carefully described and reservoir distribution was quantitatively discussed. In terms of areal heterogeneity, interlayer heterogeneity and inner layer heterogeneity, study on reservoir heterogeneity was carried out. According to the comprehensive logging interpretation, oil/ water/ gas distribution law was summarized.Multistage phase dominated geological modeling was used to construct single sand body model. Based on the varied difference function analysis, reservoir parameter model was established to aid in the description of reservoir distribution. 3D modeling was introduced.On the basis of net pay, the historical matching related to OOIP was conducted. Comparison between the matched OOIP and the actual OOIP from database was made.ECLIPSE modeling method was used to export the geological modeling data to establish the geological model of target area. Historical matching in terms of target area was made and geological model was corrected. Based on the modified numerical model, the remaining oil distribution in target area was discussed. Four sandstone units in Fuyu formation were selected as pilot areas to implement the operation of water flooding. In combination with the historical matching, the relevant injection production parameters were optimized. These parameters include the injection volume, injection rate, rational ratio of injection-production,reservoir pressure maintenance, liquid production, water swept area and the development of remained oil. On the basis of forecasting for water driving development indexes of pilot areas,economic appraisal regarding to the fine water flooding and economic benefits was conducted.A survey concerning with the domestic formula system to control the profile and efficient chemical flooding system was made. It’s helpful for the optimization of chemical flooding. Numerical modeling was also introduced to the study on the timing to transfer water flooding to chemical flooding. Some parameters including the cumulative liquid production, cumulative oil production and oil recovery are discussed. Considering reservoir characteristics and flow behavior, some evaluation based on the available data and parameters were made to determine the optimized chemical flooding system and reservoirs which are access to chemical flooding. The reasonable slug size in profile control was also given. Based on the previous geological study and remaining oil distribution analysis, suggestions on profile control system were put forward. The investigation on optimization of slug in chemical flooding was made on the basis of study on chemical flooding formula system. |
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