Study On Sealing Performance Of Carbon Dioxide Flooding Gas Well Packer

With the exploitation of oil and gas resources, the short of energy has become increasingly serious. Meanwhile, as the greenhouse effect caused by CO2become more and more serious, how to curb the growth of greenhouse effect has become a hot issue today. Studies have shown that putting CO2in oil and gas geological reservoirs is an effective way to solve these two problems. On one hand, the content of CO2in atmosphere has been reduced, greenhouse effect has been slowed down too, on the other hand, the recovery of oil and gas fields has been improved because of the dioxide flooding effect.In the production process of oil and gas, the packer is an extremely important component which can isolate well fluid and seal production layer or target layer. While the rubber barrel is the core component in the packer which has the primary sealing effect, therefore researching the sealing performance of packer rubber barrel is very important for production. However, in CO2injection wells, gas may migrate to the annular between the strings due to leakage of tubing and casing, failure of packer or leakage of cement, thus causing the sustained casing pressure which can make the force imposed on packer more complex.Firstly in this paper, the development, category and structure of packer is studied, then a set of method of computing the maximum allowable pressure in tubing and casing is given. Based on the method, the forces imposed on the packer in CO2injection well is analyzed, then a set of method of computing the load of packer is given. This method is used to calculate Well Hei X. Secondly, finite element analysis for packer rubber barrel has been done using the load calculated as boundary conditions. Simulation results shows that when the height is75mm, increase thickness as possible and make the bevel angle45°the rubber barrel has the best performance of sealing. The sealing performance can also be improved effectively by installing device which can prevent should extruding, by a biaxial loading or by decrease the friction. Finally, a set of load-bearing rubber material corrosion experiment which simulating the situation under the CO2injection wells has been designed and conducted. Results show that the corrosion is the result of combined corrosive media and load.