基于灰色关联的压裂液渗吸主控因素分析

Key Controlling Factor Analysis of Hydraulic Fracturing Fluids Imbibition Based on Gray Correlation Method

渗吸作用是影响致密储层开发效果的重要因素,明晰压裂液渗吸机理及影响因素作用规律对于评价致密储层压后生产特征意义重大。基于新疆致密砂岩储层岩心,采用体积法开展了饱和油致密岩心压裂液渗吸实验,研究了压裂液体系、岩心渗透率、实验温度、岩心长度和原油黏度对渗吸速率及渗吸采收率的影响,并基于灰色关联度对渗吸因素进行了影响程度评价。研究表明:渗吸采收率与渗透率、实验温度正相关,与压裂液质量分数、岩心长度和原油黏度负相关,渗吸速率初始较快,随后迅速下降;各渗吸因素对渗吸采收率的影响程度排序为压裂液体系>原油黏度>实验温度>岩心长度>岩心渗透率,致密储层压裂后应对储层性质及注入流体性质进行综合评价,为压后生产特征分析提供依据。

Imbibition is a key factor which decides the effect of tight formation development,and clarifying the hydraulic fracturing fluids imbibition mechanism and influencing factors have a great significance to the production characteristics after hydraulic fracturing.Volume method was adopted to conduct hydraulic fracturing fluids imbibition experiments with oil-saturated cores,and then effect and influencing degree of hydraulic fracturing fluids,core permeability,experiment temperature,core length and oil viscosity on imbibition recovery and rate had been studied.The results show that recovery changes positively with permeability and experiment temperature,and it changes negatively with hydraulic fracturing fluids,core length and oil viscosity.Imbibition rate presents a fast increase at beginning,and then drops quickly at the followings.The influencing sequencing of factors is:hydraulic fracturing fluids >oil viscosity >experiment temperature >core length >core permeability.Comprehensive evaluation should be conducted after hydraulic fracturing to give support to the development.