大庆石油地质与开发2025，Vol.44Issue(2)：167-174,8.DOI:10.19597/J.ISSN.1000-3754.202401010
页岩储层压裂后返排支撑剂回流及裂缝导流能力变化规律
Variation laws of proppant backflow and fracture conductivity of flowback after fracturing in shale reservoir
摘要
Abstract
In order to clarify laws of proppant backflow after fracturing in shale oil reservoir,the influence of flow-back sand production on fracture conductivity is studied.Split rock slabs of Yanchang Formation shale oil reservoir in Ordos Basin are selected to design laboratory experiment including 2 phases of proppant backflow test and frac-ture conductivity test.The influence of different factors on proppant backflow in fractures is analyzed,the law of fracture conductivity loss caused by fracture sand production is defined and the effect of optimized placement parrten on reducing proppant flowback and maintaining fracture conductivity is studied.The results show that clo-sure pressure has the most influence on critical backflow rate of flowback fracture after fracturing,followed by prop-pant particle size,sand concentration and flowback fluid viscosity,with backflow sand production rate positively correlated with sand concentration.Uneven proppant placement in rough wall fractures leads to easier backflow.Af-ter proppant backflow,fracture conductivity decreases significantly with the increase of closure pressure,and the smaller the particle size is,the more the decrease is.At closure pressure of 20 MPa,40/70 mesh quartz sand de-creases as much as 26.9%.Higher proportion of large-diameter chase proppant placement is more conductive to in-creasing critical backflow rate,reducing sand production rate and maintaining high fracture conductivity.The re-search provides theoretical guidance for considering the influence of flowback after fracturing and optimizing fractur-ing design to match conductivity requirements.关键词
页岩储层/压裂后返排/临界回流流量/回流出砂率/裂缝导流能力Key words
shale reservoir/flowback after fracturing/critical backflow rate/backflow sand production rate/frac-ture conductivity分类
能源科技引用本文复制引用
吴涛,宋明明,袁旭..页岩储层压裂后返排支撑剂回流及裂缝导流能力变化规律[J].大庆石油地质与开发,2025,44(2):167-174,8.基金项目
国家自然科学基金项目"致密油储层人工裂缝网络形成机制及其流体多场耦合渗流理论研究"(52074226). （52074226）
