Multi-Objective Optimization Design For Perforation Of Casing

Perforation completion has become one of the most important completion methods used in oil fields at home and abroad.Optimum design of casing perforation parameters is of great significance to casing stability and oil recovery.The perforation hole changes the casing structure and reduces the casing collapse strength.When perforated casing is subjected to external forces,damage of casings is prone to occur.It is necessary to determine the impact of perforation parameters on collapse strength of casing.At the same time,perforation completion parameters also have a great impact on productivity of oil and gas well.A three-dimensional spatial model of casing-stratum-formation is established by ABAQUS to study the influence of perforation parameters on casing strength.Through the simulation analysis and calculation of the three-dimensional model,the orthogonal numerical test difference analysis of perforated casing is carried out,and the influence rule and significance of perforation parameters on casing strength are determined.By using the nlinfit fitting function of MATLAB,the function between the compressive strength coefficient of perforated casing and perforation parameters is obtained.Combined with the productivity calculation formula of perforated wells,the influence of perforation parameters on the productivity of perforated wells is analyzed,and the optimum interval of perforation parameters is determined.Orthogonal test method is used to optimize perforation parameters of each casing to achieve the goal of multi-objective optimization.