【摘要】 对处于特高含水期开发的油田,只有搞清低效无效循环场的分布,才能有针对性地开展无效注水治理,从而改善水驱开发效果。大庆长垣油田油层多、非均质性强、层系井网复杂,低效无效循环严重。基于物质守恒原理和容量阻力模型,提出了改进的分阶段低效无效循环场定量评价方法。将注采井作为输入输出系统,建立基于单砂体注采关系评价的以井组为单元的分阶段容量阻力模型,运用集合卡尔曼滤波同化方法,通过单井液、油指标自动拟合,确定注采井间优势渗流方向;综合考虑渗透率分布、砂体连通质量等,建立非均质两相渗流阻力模型,定量评价各小层注采方向的注水量、产液量及含水率等指标;结合低效无效循环含水率界限,实现小层各方向上的低效无效循环场定量识别,并指导典型区块油水井措施调整。该识别方法具有操作简便、效率高等特点,已编制成软件系统,现场应用取得较好效果,对多层砂岩特高含水油田低效无效循环识别与治理具有指导意义。更多还原

【Abstract】 In the light of ultra-high watercut developed oilfields, only making sure of the distribution of the low and no-efficiency-cycle flow field can take the corresponding measures to manage the no-efficiency injection and improve the displaced effects of the water flooding. Daqing Placanticline Oilfields are characterized by multi-reservoir, strong heterogeneity, complex well pattern and serious low and no-efficiency cycles. Based on the principle of energy conservation and capacity resistance model(CRM), the improved quantitative evaluating method of the staged low and no-efficiency cycles was presented. By means of taking the injecting-producing wells as the input-output system, the staged CRM taking the well group as the unit was established based on the evaluation of the individual-sandbody injection-production relationship, and moreover with the help of the assimilating method i.e. the ensemble Kalman filter(EnKF), by means of the automatic matching of the individual-well liquid and oil indexes, the dominant flow directions among the injection-production wells were determined;comprehensively considering the permeability distribution, sandbody connected quality and so forth, the model of the heterogeneous two-phase flow resistance was established to quantitatively evaluate the water injection, liquid production, water cut and the other indexes for each sub-layer in the injection-production direction;combined with the limits of the low and non-efficiency cycle watercut, the quantitative identifications of the cycle fields stated above in each direction were realized for the sub-layer, and furthermore the measure adjustment of the oil and water-injecting wells in the typical block was guided. The identifying method is characterized by easy-to-use, high efficiency and so on, and has compiled into software system, and moreover much better effects have achieved for the field application, thus a certain guidance has been provided for identification and management of the low and non-efficiency cycles for the multilayered sandstone oilfield with ultra-high water cut.更多还原