Optimization Research On Construction Scheme Of Cement Plugging For Horizontal Well

Because of casing damage,casing channeling,high water content and other reasons,down hole plugging implementation is highly needed.One of the common plugging agents is cement slurry system.There are many differences between horizontal and vertical well structures.The common plugging technology applying to horizontal wells may cause many troubles.This essay is aimed to study on the performance of plugging agent system supporting tools,plugging operation procedure and operation parameters of plugging,according to the characteristics of horizontal well plugging construction.There are two major technical problems in international horizontal well plugging field.One is the poor plugging quality of the upper space in the hole caused by the cement slurry gravity settling characteristics.The other is the difficulties of the plugging drilling.Based on the analysis of difficulties of the horizontal well plugging and deficiency of the conventional plugging technology,this essay optimizes the construction scheme of cement slurry plugging in horizontal wells from the aspects of plugging agent system,construction technology and construction parameters.Through the research on the construction technology requirements selection and checking of leakage channeling technology optimization,performance optimization,cement slurry plugging technology selection,construction parameters,plugging tool,theoretical basis is provided for the design scheme of horizontal well cement plugging operation.For this essay,the research of cement slurry and polymer plugging agent composite sealing was carried out.The polymer plugging agent has the characteristics of no solid particles,similar density to water,immiscible with water or oil,and high strength after solidification.The problems of gravity sedimentation will be avoided due to its characteristics of the similarity density between water.It can penetrate into the formation of deep distance because of solid free;and the property of immiscible with water or oil makes it have a better ability to reside consolidation.According to the properties of cement slurry and polymer,the technology of plugging the horizontal well with the combination of cement slurry and polymer is considered in this essay.The plugging technology of the combined plugging agent,which elaborates the characteristics of plugging agent and forms a high strength plugging system,can effectively improve plugging effects and success rate when applied to the local plugging of the horizontal well.