模糊综合评判方法判断低效循环井层

疏松砂岩油藏注水开发后期，在油水井之问形成了储层大孔道，导致注入水沿大孔道做低效循环，油井产量下降。为改善注水效果达到控水稳油目的，必须采取低效循环井层调剖、封堵等措施，而有效识别低效循环井层是问题的关键。通过分析大孔道形成的影响因素以及在开发中表现出的特征，确定出低效循环油水井判定指标，利用模糊综合评判方法初步选定低效循环油水井。然后通过小层静态数据与沉积微相对比，以及油水井的相 关性对比，最终确定出低效循环井层。基于此方法编制成软件，对大庆油田北三东东块低效循环井层进行了判断，与人工选择结果对比符合率为81．7％。该方法切实可行，并且大大提高了工作效率和客观、准确性。

ESTIMATION OF LOW EFFICIENCY CIRCULATION LAYERS BY FUZZY COMPREHENSIVE JUDGMENT METHOD

In loose sandstone reservoir, high capacity channel would be formed between oil well and water well in the anaphase of water flooding development, which caused the injected water flow circulate at low efficiency, and decreased the oil wells production. The measure of profile control or water shutoff must be taken in order to improve the injection effect, and the key problem is to identify the low efficiency layers. In this paper, the influence factors of forming high capacity channel and its development characters have been analyzed, and the judging indexes of low efficiency circulation well have been determined. Low efficiency wells have been elementary selected by using the method of fuzzy judgment. By the contrast of static data of each layer and sedimentary facies, and the contrast of correlativity between oil wells and water wells, layers with low efficiency circle have been made out ultimately. Using the compiled software based on this method, data of North-Sandongdong block in Daqing Oilfield have been studied. The coincidence rate of results between the software and artificial choice was 81.7%. This method is feasible, and it can improve the work efficiency and veracity.