Simulation Of Working Behavior Of HPHT Well Completion Packer

HT/HP completion packers are mainly used for deep well and ultra-deep well completion operations,during the working process,the components of the completion packer,such as the rubber,the slip,and the locking mechanism,are easily destroyed under high temperature and high ’pressure,which results in the failure of the packer,ultimately affecting the oil field operation and causing extremely high safety risks.Therefore,in order to understand the actual stress of the packer at the bottom of the well,this paper first establishes a three-dimensional simulation model of the MHR completion packer,and analyze the force of the packer under well completion-reforming conditions and hazardous conditions;then analyze the force of the locking mechanism;finally,the packer setting experiment was designed to study the contact stress relationship between the rubber and the sleeve.Using ABAQUS finite element analysis software to establish a three-dimensional simulation analysis model of MHR completion packer,according to its working principle,more than 400 pairs of contacts are established between the various components,dividing the number of grids by more than 5 million,the force data of the packer under a dangerous working condition and well completion-reforming conditions are used as the simulation analysis load based on a well in Xinjiang.The simulation analysis shows that the MHR completion packer is the most dangerous phase in the reform process during the five stages of well completion-reformation;The packer is not evenly stressed and the lower part is the most stressed;the central tube is the most stressed in all parts and the stress concentration occurs after the packer is set;under the dangerous load,the force in the lower part of the packer is greatly increased,the maximum equivalent stress in the lower part of the central tube exceeds the yield limit,and the rubber tube is deformed when the upper and lower pressure differences are large,the packer has a large potential safety hazard.Moore theorem was used to obtain the formula for calculating the deformation amount ofthe locking ring,the mechanical model of the MHR completion packer locking mechanism was established by using the static theory,and the mechanics distribution law of the locking mechanism was obtained by using the finite element simulation technique:the deformation of the locking ring decreases with the increase of the wedge angle of the locking ring;the locking ring opening angle has a smaller influence on the deformation of the locking ring;as the axial pressure increases,the force of the locking ring and the central tube are increasing;the force of the locking ring increases and the force on the central tube decreases with tooth width of locking ring increasing;the locking ring and central tube are not evenly stressed,stress concentration at thread connections.The packer setting process experiment was designed to obtain the change law of the contact stress between the cartridge and the sleeve:the force of casing is greatly increasing when the rubber contacts with the casing;the rubber force near the loading end is larger than the rubber far from the loading end,the same rubber has a uniform force in the hoop,but the axial force is uneven,the force of shoulder is larger.The finite element analysis model was established for the simulation experiment conditions,the analysis results and the experiment have similar mechanical laws.