Fracture sealing performance of granular lost circulation materials at elevated temperature:A theoretical and coupled CFD-DEM simulation study  

作　　者：Chong Lin Qi-Cong Xu Lie-Xiang Han Gao Li Hai He Hong-Ling Zhou Ji-Ping She 

机构地区：[1]CCDC Drilling&Production Technology Research Institute,Guanghan,618300,Sichuan,China [2]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,610500,Sichuan,China [3]College of Materials Science and Engineering,Chongqing University,Chongqing,400044,China [4]State Key Lab of Oil and Gas Reservoir Geology and Exploitation(Chengdu University of Technology),Chengdu,610059,Sichuan,China [5]College of Energy,Chengdu University of Technology,Chengdu,610059,Sichuan,China

出　　处：《Petroleum Science》2024年第1期567-581,共15页石油科学（英文版）

基　　金：The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(Grant No.52274009);China Postdoctoral Science Foundation(Grant No.2022M723501);Science and Technology Planning Project of Sichuan Province(Grant No.2021YJ0359).

摘　　要：Lost circulation is a common downhole problem of drilling in geothermal and high-temperature,high-pressure(HTHP)formations.Lost circulation material(LCM)is a regular preventive and remedial measure for lost circulation.However,conventional LCMs seem ineffective in high-temperature formations.This may be due to the changes in the mechanical properties of LCMs and their sealing performance under high-temperature conditions.To understand how high temperature affects the fracture sealing performance of LCMs,we developed a coupled computational fluid dynamics-discrete element method(CFD-DEM)model to simulate the behavior of granular LCMs in fractures.We summarized the literature on the effects of high temperature on the mechanical properties of LCMs and the rheological properties of drilling fluid.We conducted sensitivity analyses to investigate how changing LCM slurry properties affected the fracture sealing efficiency at increasing temperatures.The results show that high temperature reduces the size,strength,and friction coefficient of LCMs as well as the drilling fluid viscosity.Smaller,softer,and less frictional LCM particles have lower bridging probability and slower bridging initiation.Smaller particles tend to form dual-particle bridges rather than single-particle bridges.These result in a deeper,tighter,but unstable sealing zone.Reduced drilling fluid viscosity leads to faster and shallower sealing zones.

关 键 词：Geothermal well drilling HTHP formationLost circulation material CFD-DEM Fracture sealing 

分 类 号：TE28[石油与天然气工程—油气井工程]