Study On The Remaining Oil Distribution After Polymer Flooding In Unit Sa ? 4-10 In Beidong 1st Area

Block 1 of the North East Block of Lamadian Oilfield has now entered the mid-term stage of development in the ultra-high water-cut period,and tapping the potential of the remaining oil after high-concentration polymer flooding is the focus of work to ensure the stable production of the oilfield.Based on the fine geological model,this paper uses the production data of oil and water wells in the water flooding stage and the polymer flooding stage to carry out history matching and obtain the remaining oil level distribution of different units.At the same time,multiple sets of comparative tests were used to carry out the design of polymer flooding schemes,so as to provide guidance for the later adjustment of remaining oil potential tapping measures.Establish a fine geological model and use the corner grid method to establish a three-dimensional structural model of the target layer in the study area.Using the GPTMAP processing program,the digitization of the deposition microfacies of the target layer in the study area was realized,and a three-dimensional deposition model of the target layer was established.Using the sequential Gaussian simulation process and the stochastic method,the attribute models representing the physical development degree and fluid distribution of the target layer were established respectively.Under the constraints of sedimentary facies,a three-dimensional fine geological model of the target layer was established.Numerical simulation results show that the Sa III4-10 water flooding stage in Northeast District 1 has produced a total of 773,000 tons of oil as of September 2008,which is the Sa III4+5 layer,with a recovery rate of 38.42% and an overall recovery rate of 36.3%.The remaining geological reserves after polymer flooding are 85.48×104t.Analyze the effect of polymer flooding is affected by the heterogeneity of the reservoir plane.The high value of remaining oil saturation after flooding is mainly in the low-permeability parts with poor physical properties,and the positions where the sand body distribution and well pattern are weakly matched..Based on the analysis and optimization of polymer colloid concentration,injection rate,dosage,and slug combination,comparative experiments were used to analyze the influence of polymer colloid concentration,injection rate,colloid dosage,and slug combination on the recovery factor.Constrained by the deposition cost,the polymer flooding method has optimal parameters and slug combination methods.The production simulation of vertical wells was carried out using the optimal scheme,and good prediction results were obtained.