注采井间优势通道的多层次模糊识别方法

为了正确识别并评价注采井间优势通道的发育情况，制定合适的调剖堵水措施，针对其识别过程的复杂性和模糊性，提出了基于层次分析法与模糊综合评价相结合的多层次模糊综合评价指标体系（AHP-FCE）。该评价指标体系包括3个评价对象子系统和25个评价指标，其中注采井间的连通性通过灰色关联度进行定量表征。将该模型应用于N油田S14层优势通道识别，建立了一级优势通道、次级优势通道、正常孔隙通道3种评价等级，利用熵权法确定各因素权重，选择半梯形隶属度函数计算隶属度矩阵，并根据最大隶属度原则对各注采方向进行了优势通道模糊综合评价。结果表明：共识别出一级优势通道16处、次级优势通道10处，高渗透层及注采关系不完善的井间优势通道发育明显；经过井间示踪剂法验证，识别准确率达87.5%。该方法合理准确，可为油田后期实施调剖堵水措施提供指导。

Multi-level fuzzy identification method for interwell thief zone

In order to correctly identify and evaluate the development of the thief zone, and take appropriate blocking measures, considering the complexity and fuzziness of the identification process of the thief zone, a multi-level fuzzy comprehensive evaluation index system(AHP-FCE)based on AHP and fuzzy comprehensive evaluation method was proposed. The evaluation index system consists of three evaluation object subsystems and 25 evaluation indicators, and the interwell connectivity is represented by grey relational degree. The model was applied to the identification of the thief zone in the S14 layer of N oilfield, and three evaluation levels of primary thief zone, secondary thief zone and normal pore channel were established. The weight of each factor was determined by entropy weight method, and the membership degree matrix was calculated by choosing semi trapezoid membership function. According to the principle of maximum membership degree, the thief zone of each interwell was evaluated. The results show that there are 16 primary thief zone and 10 secondary thief zone, and the development of the thief zone is more obvious between the interwells with high permeability and imperfect well pattern relations. The identification results were verified by the well tracer method, and the accuracy rate was 87.5%. The results show that this method is reasonable and accurate, and can provide a clear guidance for profile control or water shut off in the later stage of oilfield.