Study On The Anti-squeezing Ability Of Casing In The Complex Well Condition Of The Curved Section Of Horizontal Wells

With its unique advantages,horizontal well technology is widely used in major oilfields at home and abroad,and many types of horizontal wells with different production requirements have been developed.The development and utilization of these technologies have improved oil recovery to a certain extent and significantly reduced production costs,but the use of these technologies has also raised new problems for the design and prevention of casing damage in horizontal wells.The reduction of tube crushing strength has become one of the key factors restricting the development of horizontal well technology in certain regions.In this paper,by referring to domestic and foreign literatures on the bending strength of the casing,the stress situation of the casing extruded model is analyzed,and the casing strength formula is summarized and given.Calculation formula of casing squeezing strength under different working conditions.This paper focuses on the influence of influencing factors such as casing bending load on the bending section of horizontal wells,and derives the calculation formula of its crushing strength.Through the combination of theoretical calculation and ANSYS finite element simulation,the variation law of curvature and crushing strength is studied.The meta-simulation of the change law of the squeezing strength of the casing under various complicated working conditions.First,based on the theoretical knowledge of elastic mechanics and material mechanics,the formula for calculating the ellipticity of the casing under the bending state is derived,and it is substituted into the KT model formula,and then the KT formula is improved by introducing the bending coefficient to make it more accurate Calculate the crushing strength of the curved sleeve.Secondly,the ANSYS finite element software was used to simulate and analyze the curved casing to verify the accuracy of the theoretical derivation formula.By comparing the theoretical and finite element data,it was found that the error of the ellipticity of the curved casing was within 20%,and the error of the crush strength was Within 10%,it shows that the derived theoretical formula has a high degree of credibility,which provides a new calculation formula for the design of casing in the bending section of horizontal wells in the future.Finally,the finite element software was used to analyze the casing squeezing strength of the horizontal well casing under the complicated conditions of corrosion,wear,non-uniform load,cement ring defects and eccentricity,which provided the necessary theory for the design of the actual project.basis.