Study On Optimal Structure Of JY445 Gas Drive Packer Rubber Barrel

As an important downhole tool for oil field stratification process,packer is widely used in well completion,water injection,fracturing,acidification,sand control,mechanical oil recovery,gas lift and other production technologies.The rationality of rubber barrel structure design and the reliability of sealing performance of packer play a decisive role in the safe and reliable sealing of the whole packer.Existing research on single factor analysis of hydraulic packer rubber tube structure,and factor interaction study of gas packer rubber tube is relatively small,therefore,according to the operation condition of the packer rubber tube,and the use of performance requirements,finding out the optimal combination of the rubber tube structure,studying the factors and rules on influencing the sealing performance,to improve the packer rubber tube sealing performance and outburst prevention is of great significance.Paper to JY445 packer supporting the combination of the rubber tube as the research object,on hydrogenated nitrile rubber material,using the Mooney-Rivlin constitutive model,the three-dimensional finite element model was established by the finite element analysis software,the selection of contact stress between rubber tube and casing and displacement of steel cage as a rubber tube sealing performance and the performance of outburst prevention measures,in 7.6 t setting force and 35 MPa pressure load finishing the simulation of the tube setting and bidirectional test process.A special test tool for rubber cylinder was designed to test the pressure resistance of packer rubber cylinder.Compared with the simulation test,the validity of the finite element model was verified.Under the setting force of 7.6t,the single factor analysis was carried out on the five factors including the height of the middle rubber cylinder,the height of the steel cage,the angle of the end face of the middle rubber cylinder 1,the angle of the end face of the middle rubber cylinder 2,and the thickness of the middle rubber cylinder respectively,and the optimal selection interval of the factors was determined.The response surface model was obtained by numerical simulation fitting using response surface design method,and the optimal combination of rubber cylinder was obtained.Analytic Hierarchy Process(AHP)-entropy weight method was used to establish a double index comprehensive evaluation model,the weight scoring function of the model was calculated,and the evaluation scheme with the highest score was obtained.The results of the optimal combination and the scheme with the highest score are consistent,and the final optimal structure of the packer rubber barrel is obtained.The sealing test of the structure was carried out to verify that the sealing effect of the rubber cylinder was achieved under the optimal factor conditions.