基于正交试验的致密油渗吸影响因素分析

针对压裂施工过程中渗吸增产效果受储层性质、作业条件等多种因素影响的问题，开展了不同因素对渗吸采收率影响的量化研究。以渗吸理论为基础，结合新疆油田致密油M区块的储层特征和开发状况，利用自行研发的电子式高精度静态渗吸装置，对影响渗吸的6个因素进行了室内对比实验。在简化实验过程、提高实验精度的基础上，得到了渗吸液体系、渗透率、原油黏度、界面张力、润湿性和防膨剂含量对采收率的影响规律；并基于L₉(34)正交表设计了正交试验，通过较少的试验次数得出其中4个主要因素对渗吸采收率影响程度大小的排序，从大到小依次为:界面张力、渗透率、原油黏度、润湿角。该结论不仅为M区块现场作业压裂液类型的选择和配方的优化以提高渗吸采收率提供一定的理论依据和技术指导，也可为其他致密油区块的压裂施工和提采增效提供参考。

Analyzing the factors influencing the imbibition of tight oil based on orthogonal experiment

The stimulation effect of imbibition in the process of fracturing construction is influenced by a variety of factors, such as reservoir property and operation condition. To solve this problem, a quantitative study on the influences of different factors on imbibition recovery were carried out . Based on the imbibition theory, combined with reservoir characteristics and development situations of the M Block of tight oil in the Xinjiang Oilfield, laboratory contrast experiments were performed on 6 imbibition influencing factors by using the independently developed high-accuracy electronic static imbibition device. After the experimental process was simplified and the experimental accuracy was improved, the influential laws of imbibitions fluid system, permeability, crude oil viscosity, interfacial tension, wettability and antiswelling agent content on the recovery factor were clarified. In addition, based on L₉(34) orthogonal list, orthogonal experiments were designed. And the influential degrees of 4 main factors on the imbibitions recovery were ranked on the basis of fewer experiments. From the largest to the smallest were: interfacial tension, permeability, crude oil viscosity and wetting angle. This conclusion not only provides some theoretical basis and technical guidance for the type selection of fracturing fluid and the optimization of formula on site in M Block so as to improve the imbibition recovery, but also provides the reference for fracturing construction and production and efficiency increase of other tight oil blocks.