利用采油速度干扰系数评价油藏层间干扰

多层油藏合采时，层间地层压力将自动平衡，会导致注水开采阶段合采各层水淹程度及水驱动态特征具有较大的层间差异，降低了注水油藏的整体采收率。因此，需实时评价层间干扰，并制定合理的井网加密及层系细分调整方案，以提高储量动用的均衡程度。针对多层油藏注水开发中后期的层间矛盾，以开发过程中层间压力及水淹程度的变化差异为基础，利用油藏工程及数值模拟方法建立评价储量动用层间均衡程度的影响因素图，以油藏整体均衡动用为目标，分析注采过程中水淹及压力的层间变化差异对整体开发效果的影响规律。采油速度能够同时体现产能大小及储量动用程度，借鉴产量层间干扰系数的定义，建立了采油速度层间干扰系数的计算方法。结果表明，利用采油速度层间干扰系数能够更加合理地评价合采各层的均衡动用程度，并为制定层系细分界限提供定量依据。

Interlayer Interference Evaluation by the Recovery Rate Interference Factor for the Waterflooding Oil Reservoir in the Medium-late Period

Pressure between payzones that connect the production or injection wellbore will be balanced automatically. This process will deplete production degree of each layer but increase difference of pressure and fluid distribution of each layer for water flooding reservoirs. In the Medium-late period after Overall Development Plan(ODP), the real-time adjustment or modification were required since the ODP may not be the best as long as more and more static and dynamic information from reservoir has been put into the reservoir model. In addition, the performance of interlayer interference will keep changing following in-situ stress and fluid distribution during production and injection development procedure. It is obvious that criteria are required to make the reasonable infill and strata subdivision plan in the medium-late development phase. In this study, the interlayer inference was evaluated by the oil recovery rate interference factor with productivity and reserves and was defined as the ratio of oil recovery rates between commingling payzones. Furthermore, the analysis charts were calculated by numerical simulation to evaluate the balanced level of commingling multilayer reservoir development. The results indicated that production rate adjustment can fix lower level unbalanced development due to minor interlayer interference phenomena and strata subdivision is required during higher heterogenous waterflooding. Results show the best development performance would be the equal oil recovery rate between each commingling payzones.