Study On The Gradual Plugging Strategy Of Multiple Thermal Fluid Flow

At present,in the process of heavy oil thermal recovery,the problem of multiple thermal fluid flow is becoming more and more serious.How to prevent and control the flow of multiple thermal fluid is one of the key problems that restrict the development of offshore heavy oil.The heavy oil exploitation of multi thermal fluid is a dynamic process,with the development of significant changes in reservoir conditions will increase the multiple thermal fluid channeling plugging technical difficulty: the first multi thermal fluid belongs to high temperature fluid under high temperature conditions,ordinary plugging agent is difficult to apply;the time with the development of stratum,heterogeneous enhancement the advantage,seepage channel formation,channeling phenomenon intensified.In this paper,to solve this problem,gradual plugging technology of multiple thermal fluid flow is proposed.In space,according to the different permeability,with different types of plugging agent system: channeling and other serious heterogeneous areas with high strength plugging agent,the common heterogeneous area used foam plugging;time,according to different stages of development and the main contradiction and difference of multiple rounds of plugging,resulting in multiple heat the fluid flow by plugging method.In order to realize this idea,the two problems need to be solved are the selection of high temperature resistant and high strength plugging agent and the rational use of plugging agent.In this paper,by adding alkali lignin system in the high temperature resistant foam,the foam stability and plugging strength are increased,and then the foam plugging strength is enhanced.The plugging agent system can be gelled in the range of 100 DEG C ~250 DEG C,and the gelling property can be maintained at more than 85% after heating 72 h.Through the experimental evaluation of the alkali lignin foam system and water plugging ability and oil temperature,fluid composition,gas-liquid ratio,water saturation,permeability,permeability,injection mode and injection quantity of alkali lignin foam plugging performance,and several common plugging system are compared and evaluated.The results of physical model experiments show that the alkali lignin foam system has good plugging ability.The numerical simulation software was used to simulate the process of alkali lignin foam system,and the experimental results were fitted.By using the method of numerical simulation analysis of typical reservoir multi thermal fluid in the process of development,different development stages,the multiple thermal fluid channeling reservoir in different position of the flow rule,and according to the previous plugging strategy analysis,establish different multiple thermal fluid flow model,the multiple thermal fluid channeling plugging template strategy gradually.