Preparation And Performance Of High Temperature Resistant Temporary Plugging Agent For Wellbore

At present,the leakage and effluent of the oil and water wells are more and more serious,the existing plugging agents are not resistant to high temperature,and the thermal stability is poor.so they failure to meet the requirements of high temperature plugging.Therefore,this paper addresses the above problems,aimed to develop a high-temperature temporary plugging agent.In this paper,a temporary plugging agent with high temperature resistant,high breakthrough pressure,low viscosity was developed.The optimal formula for the temporary plugging system was determined to be 20% monomer,9:1 monomer ratio.0.6% cross-linking agent,0.006% initiator,and 0.3% reinforcing agent.This article evaluated the high-temperature temporary plugging system,such as the effect of temperature on the gelation time,the effect of salinity on strength,saltwater washout resistance,microscopic performance evaluation,rheological performance evaluation,injection performance evaluation,and breakthrough pressure evaluation.The results show that the temporary plugging agent can retain 90 days thermal stability with 3×104mg/L mineralization at 120?.The high-temperature temporary plugging agent system has dense microscopic structure and has a predominant temperature resistance performance.The high temperature resistant temporary plugging agent system has a very low viscosity so it has good injectability.After shearing,the viscosity of the solution remains basically unchanged and a strong gel can also be formed.The breakthrough pressure of temporary plugging agent is 960 k Pa/m,which has a good plugging effect and is expected to be used for high temperature plugging operations.