Research On Sealing Performance Of Thermal Injection Well Packing Packer

Along with the development of oil fields,deep wells,ultra-deep wells and thermal wells have appeared in a large number of major domestic oil fields.The high temperature packer,as an important tool in thermal recovery,provides guarantee for the successful realization of various thermal recovery technologies.At present,the packer seals used in high-temperature wells are mainly mental seals and PTFE-based graphite seals,which are inelastic materials and cannot achieve second or more times sealed and unsealed.Therefore,it has great signifi-cance to study the properties of high temperature packer.Firstly,we give preference to the rubber materials,and prepare four rubber cylinders with different recipes through the reference to the recipe of rubber cylinder material.The four different recipes cover three raw rubber fluorine rubbers with different grades and two kinds of curing systems.The mechanical properties of the prepared rubber materials are tested.Through the test,the raw rubber grades were optimized,and the vulcanization system is pref-erably used in different proportions of vulcanizing agent.We select a model by comparing and analyzing five different constitutive models,which is suitable for rubber cylinder simulation.Then the force analysis to the packer rubber cylin-der was carried out,and the finite element model of the packer rubber cylinder was built.Ac-cording to the material properties of rubber cylinder and other metal parts,the main parame-ters and boundary conditions for the finite element simulation can be set.After that,we can simulate the best end angle of the packer rubber cylinder,and the range of length and thick-ness of the rubber cylinder.Since the corrosion situation of rubber cylinder within the wellbore cannot be reflected truly by the device and method of the erosion test of the packer rubber cylinder,we designed a high temperature corrosion device of the packer rubber cylinder by ourselves.The device is equipped with heating system,temperature control system and pressurization system.Thus,a high temperature corrosion test platform for rubber packer with the full-size packer is con-structed.The optimized recipe in the recipe study and the optimized structure calculated by the finite element simulation were selected as the experimental material.Thus,an experi-mental scheme was made,by which a series of corrosion tests were carried out to packer rub-ber cylinder under different compression distances and high temperature saturated formation water conditions.At last,macro morphology observation and mechanical properties test were combined to analyze the packer rubber cylinder after corrosion.Firstly,the corrosion situation of the full-size packer rubber cylinder after experiment was qualitatively analyzed by macro mor-phology observation method.Secondly,four kinds of mechanical properties such as tensile strength,elongation at break,hardness and 100%tensile strength of dumbbell-shaped speci-men are tested by using the dumbbell-shaped specimen intercepted from the packer rubber cylinder after experiment.From that,the mechanical properties and its changing regularity of the packer rubber cylinder with different compression distances are obtained.