| The fracturing packer is used as a downhole fracturing tool in the development of oil and gas fields.Under the axial load,the radial expansion of the packer rubber contacts the casing wall to isolate the annular space of the oil casing.Therefore,the performance and reliability of the packer cartridge directly affects the success rate and development cost of the downhole process measures.At present,most of the research on the fracturing packer rubber does not consider the influence of temperature on its sealing performance,and also lacks the prediction method of the life of the rubber.Therefore,the reliability study of the fracturing packer rubber considering temperature is of great practical value for improving the reliability and service life of the rubber under important high temperature and high pressure.Taking a certain type of fracturing packer rubber as the research object,according to its operation principle,the sealing model and durability model of the rubber were established by using finite element software,and the sealing characteristics and fatigue life value of the rubber were analyzed when considering temperature.The concepts of sealing reliability,elastic deformation reliability and fatigue damage reliability are proposed.Main tasks as follows:The maximum contact stress of the rubber at different temperatures was analyzed,and the sealing performance coefficient K was introduced as the index for judging the rubber seal.Combined with the maximum contact stress and K,the sealing reliability of the rubber at different temperatures was obtained.Combined with the torsion problem that may occur during the actual operation,the maximum contact stress value and K value and sealing reliability of the rubber under different temperatures under torsional load are analyzed.Using the.fil format file obtained by ABAQUS analysis and introducing Fe-safe,the fatigue life values of the rubber before and after the torsional load were applied at different temperatures were obtained,and the damage reliability of the rubber was obtained.The sealing reliability of the double-cylinder was considered when considering the temperature.Taking the working temperature of 100? as an example,the sealing reliability and fatigue damage reliability of the double-rubber were analyzed when the height of the upper and lower rubber were different.Studies have shown that in the case of constant axial load,the higher the temperature in the temperature range,the better the sealing reliability and fatigue damage reliability of the rubber;Under small angle torsional load,the increase of working temperature will improve the sealing reliability and fatigue damage reliability of the rubber,but will reduce the stability of the rubber rubber seal;The double-rubber combination structure with 50mm on the upper rubber and 40mm on the lower rubber has the best reliability.The upper rubber is 50mm,and and 90mm on the lower rubber has the largest service life value and the best fatigue damage reliability.Based on the compression set rate of compression rubber,the elastic deformation reliability of the fracturing packer was investigated.The four working temperatures of the target rubber were taken as examples to evaluate the elastic deformation reliability.The sealing reliability and fatigue damage reliability of different materials of rectangular rubber under temperature are studied.The reliability of the four materials studied in the operating temperature range increases with the increase of temperature,and the sealing reliability of HNBR can be improved.Preferably,the CR material rubber has the highest fatigue life value and the best fatigue damage reliability performance. |
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