Numerical investigation of non-uniform temperature fields for proppant and fluid phases in supercritical CO_(2)fracturing  

作　　者：Boyu Liu Jun Yao 

机构地区：[1]Research Center of Multiphase Flow in Porous Media,China University of Petroleum(East China),Qingdao 266000,China

出　　处：《Particuology》2024年第7期149-163,共15页颗粒学报（英文版）

基　　金：the National Natural Science Foundation of China(grant number 52034010).

摘　　要：The non-uniform temperature distribution in supercritical CO_(2)(Sc-CO_(2))fracturing influences the density,viscosity,and volume expansion or shrinkage rate of Sc-CO_(2),impacting proppant migration.This study presents a coupled computational fluid dynamics-discrete element method and heat transfer model to examine the effects of proppant bed shape and the heat transfers of proppant-wall,proppant-fluid,and fluid-wall on the fluid and proppant temperature fields.The Sc-CO_(2)volume expansion is assessed under various temperature conditions by evaluating the volume-averaged Sc-CO_(2)density.Several factors,including proppant size,shape,thermal conductivity,concentration,temperature difference,and injection velocity,are carefully analyzed to elucidate their impacts.The findings elucidate the existence of four distinct zones in the fluid temperature field.Each zone exhibits different magnitudes of temperature change under diverse conditions and undergoes dynamic transformations with the development of the proppant bed.The fluid-wall heat transfer and the fluid temperatures in Zones C and D are significantly subject to the fluid injection velocity(governing the heating duration),the temperature difference between fluid and formation(impacting the magnitude of heat flux),and the proppant bed shape(controlling the effective heating area).Additionally,the proppant-wall and proppant-fluid heat transfers determine the temperatures of both the proppant bed and the fluid within Zone B,showing a strong correlation with proppant thermal conductivity,proppant size,injection velocity,and temperature difference.The proposed coupled model provides valuable insights into the temperature distributions and flow behaviors of temperature-dependent fracturing fluids and proppants.

关 键 词：CFD-DEM Heat transfer Compressible fluid CO_(2)sequestration Proppant transport 

分 类 号：TE37[石油与天然气工程—油气田开发工程]