Study On Stress And Deformation Of Casing For Heavy Oil Well In Permafrost Region

Under the requirements of the national development strategy and the trend of globalization,the scale of infrastructure construction in our country's permafrost regions is gradually expanding,and the development of oil and gas energy in the permafrost regions has great potential,but the technology of energy extraction is not yet mature.In order to ensure the supply of domestic oil and gas energy,energy cooperation between my country and countries in the Arctic region has become more and more frequent.The diseases of oil and gas energy extraction projects in permafrost regions are mainly caused by the additional effects of frozen soil thawing settlement on the structure.my country's energy structure is in a transitional stage,and further research on the internal mechanism of oil and gas well diseases in permafrost regions has important reference significance for my country's energy development in permafrost regions.Based on the field survey data,this paper uses ABAQUS finite element software to analyze the evolution of permafrost temperature field,casing mechanics and deformation state of a heavy production well in a permafrost area during the operation period;in addition,in order to be more consistent with actual working conditions Close,considering the inevitable construction factors during the installation and construction of oil well casing,a preliminary study on the mechanics and deformation state of the eccentric casing was carried out.The main research contents and results are as follows:(1)Based on the material mechanics parameters provided by the site survey data and related literature,combined with the heat transfer theory,the ABAQUS finite element software is used to establish a three-dimensional analysis model.The model analyzes the evolution of the permafrost temperature field around the wellbore of heavy oil production wells during the operation period.(2)Through the thermo-mechanical coupling method,the results of the temperature field simulation of the heavy oil production well during the operation period are used as field variables,and a three-dimensional model of the interaction between the casing and the soil is established.The mechanics and deformation state were studied,and the mechanism of negative friction on the casing was further explored.(3)During the operation of the production well,the maximum settlement deformation of the soil at the surface is greater than that of the casing,and the settlement deformation difference between the both shows a gradually smaller trend;(4)In view of the influence of the most unfavorable axial load on the casing in the operation period of heavy oil production wells,based on ABAQUS numerical analysis platform,a parametric modeling script was written in Python language.The formation was regarded as soil spring,and a simplified model of interaction between casing and soil spring was established.The stress and deformation state of eccentric casing and non-eccentric casing were studied;Under the action of soil spring,the lateral deformation of eccentric casing is large,and its vertical deformation is larger than that of non-eccentric casing.