| Gunan oilfield is a complex fault block oilfield distributed along Gunan fault, but numerous faults as well as complication of oil-bearing series. After nearly 30 years exploiting, Although the oil production droped speedily and unclear of remaining oil distribution , it becomes more and more difficult to keep the yields of the oilfield. However, there are still areas of residual oil enrichment, and it will be potential to improve the recovery ratio in this area. Combined with the practical exploitation of Gunan Oilfield and based on reservoir geology and development geology, with assisting of computer technique and geo-mathematics, the reservoir and sedimentary facies of Gunan Oilfield, remaining oil distribution have been studied in this paper. Following the main recognizes: 1)Based on the recognition of Second Order Sequence Boundary ( the bottom boundary of Guantao group, upper bottom boundary of Sha 2 Section and lower bottom boundary of sha 3 Section), identify 9 third-order sequences in the study area ; There are 32 subsequence sets in every third-order sequence, including type of progradation, type of retrogradation and type of aggradation. Among them the type of progradation's subsequence set is most developed in the study area.2)Based on the research results of core analysis and sedimentary micro-facies, there are developing Alluvial Fan -Fan-delta and lacustrine sedimentary systems. The alluvial Fan -Fan-delta sedimentary system contains 8 kinds of sedimentary micro-facies, such as branched channel above water, flooding, swamp, branched channel under water, tributary between bays, mouth bar, distal bar and gravity flow etc.3 ) The use of new information on three-dimensional seismic interpretation of the fracture field Gunan have a new understanding of the system. The structure had very changed, thus had discovered the advantageous micro-structure and the non-well control area, the new well which deployed in these regions has obtained very good effects.4)Through to mining characteristic analysis of 131 well district of Gunan discoveried, 131 out of the aquifer and the extent of changes in mining laws in line with the S-curve,it can be to predict future developments, at the same time, Changes in aquifer production wells is mainly affected by the formation of hypertonic and injection wells. Production wells of the aquifer is mainly affected by the impact of the corresponding injection wells. Through these awareness of Gunan 131 can provide comprehensive adjustment.5)Aim at the characteristics of the remaining oil areas, some certainly measure have been adopt. For example: micro-structure and partial residual oil-rich region, the deployment of the adjustment well, the complexity of the structure of potential wells. According to the study of residual oil, the measures of the old wells fill holes, card change, water shutoff profile control and blast-hole plugging are implemented to excavate the remaining oil potential. For the difficult to use the remaining oil of the low permeability reservoir, the measures of acidification, fracturing of the industrial technology are implemented to excavate the remaining oil potential. The reservoir of relatively ready to carry out adjustment of the overall injection-production . Ready for the self-contained reservoir,it is necessary to carry out the overall injection-production strategy.
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