基于多层次模糊综合评价的剩余油分布研究方法

Application of Multi Level Fuzzy Comprehensive Evaluation Method in the Research of Remaining Oil Distribution in Xing 6 District

大庆油田杏六区油藏经过43 a的注水开发,现已进入高含水开发后期,总体采出程度高,水淹严重,地下油水关系复杂,亟需对剩余油分布进行精细研究。在对影响剩余油分布的地质因素和开发因素综合分析的基础上,结合杏六区油藏的动静态资料,筛选出4个地质因素、5个开发因素共计9个动静态因素构成剩余油潜力评价因素集。依据二次加密后取芯井资料和各小层水洗资料,对各因素进行层次划分和权重统计,运用多层次模糊综合评价法研究剩余油分布。将最终计算出的A2-7小层各单井点剩余油概率评价结果绘制成剩余油平面分布概率图,并与数值模拟结果和现场取芯分析结果对比,单层剩余油识别符合率达到86.7%。该方法能够精确预测剩余油分布,具有较高的实用性和可靠性,为类似油藏的剩余油分布研究提供了依据。

After 43 years of water flooding development, Xing 6 district of Daqing Oilfield has now entered the late period of high water cut stage. It had many problems, such as a high degree of overall recovery, serious flooding and complex underground oilwater relationship. Therefore, a detailed research of the distribution of remaining oil is urgently needed. On the basis of comprehensive analysis of the geological factors and development factors affecting the distribution of remaining oil, and making use of the dynamic and static data of the Xing 6 district reservoir, we selected four geological factors ： the types of sedimentary facies, reservoir thickness, plane connectivity, struc^xe, and five development factors： injection relationship, injection distance, well network, water status, direction by the effect. All the nine static and dynamic factors constitute the remaining oil potential evaluation factors. With coring well data and water data of each layer, we made hierarchical division and statistical weights of all the factors, and studied the distribution of remaining oil with multi level fuzzy comprehensive evaluation method. We used the final remaining oil evaluation results of each well to draw out the remaining oil plane distribution probability plots of layer $2-7. A comparison of the results with numerical simulation and core analysis results proved that remaining oil of single layer recognition accuracy is 86.7%, which means this method can predict the remaining oil distribution accurately, ang has higher practicability and reliability. This method provides a basis researches on remaining oil distribution of similar reservoir.