Pipe Column With Joint In The Well Bore Static Bucking Experiment

The buckling of pipe string is of great significance in drilling engineering.The pipe in the actual wellbore is connected by a drill pipe through a joint,which is larger than the diameter of the drill pipe and can be as high as 50%.For convenience,the influence of joint is ignored in previous studies and the pipe column is assumed to be an equal diameter beam.The research in this paper abandons the hypothesis that the joint is neglected in the tube buckling study,and uses the simulation test bench to conduct the buckling experiment with the joint column.This paper simulates the actual working conditions of drilling,and completes the design of flexural simulation test table of pipe column in wellbore in horizontal well and vertical well state.An experimental study on the static buckling of pipe string with joint was carried out by means of an experimental platform.In the experimental simulation process,the selection of joints and simulated tubular columns was studied in detail to make the experimental data more scientific.In the theoretical analysis process,the viewpoint of the joint length in the derivation of the column buckling theory is put forward: the joint length is zero relative to the overall length of the pipe column.The influence of the joint on the expansion and contraction of the pipe string during the tension and compression process is analyzed.It has made its own derivation process for the buckling process without joint pipe;and simplified,modified,sorted and perfected the theoretical derivation of Huang Wenjun's buckling with joint pipe.The static buckling experiment with jointed pipe string was carried out through a simulation test bench,and the static buckling experiment without joint pipe column was carried out.The spatial configuration of the pipe column with static joints during the static buckling process is explored to satisfy the three-stage equation.At the same time,through experimental research,it is found that the static buckling experimental data of the jointed pipe string in the wellbore and the static buckling test data without the joint pipe column in the wellbore under the same experimental conditions are obtained by the joint analysis of the pipe string in the wellbore.The force buckling has little effect on the sinusoidal buckling critical load of the simulated pipe column,and has a great influence on the spiral buckling critical load of the simulated pipe string.The critical buckling critical load of the pipe column with joint is opposite to the screw buckling of the jointless column.The load should be too large.At the same time,the article also explored the static buckling of the column for the number and size of joints.And the experimental verification of Huang Wenjun's critical load theory research on the buckling of jointed pipe columns proves the correctness of the theoretical reasoning.