The Study Of Small-Caliber Expansion Tubular's Simulation And Experiment

This paper is based on the project "Protecting Walls of Deep Hole by Expandable Tubular Technology", which is cooperated by China geological survey and China university of Geosciences. The studying of expendable tubular technology in geological coring drilling field is discussed in this paper.Based on elastic-plastic mechanical analysis of the pipe expansion, ANSYS FEM and laboratory tests, the paper systematically does a study of the forming mechanism, and obtains a series of important conclusions and understanding: 1.broughted in the theories of cold working of metal and elastic - plastic, the mechanical model of expendable tubular is established, FEM simulation and experimental studies have shown that the establishment of the mechanical model is scientific and rational, and the expansion force formula is practical; 2.at some level, the expansion force approximate linear with the diameter, wall thickness, the material yield strength and the expansion scope, it increases with the increase of the influencing factors; 3. cone angle designing is the important part of the design of the cone head, it is found that along with the increase of cone angle, expanding force first increased, then decreased, and the appropriate angle is 7-10°; 4.when solid cone expands, the casing axial length become shorter, wall thickness become thinner; when rotary compliant expands, the casing axial length increase slightly; 5. with the increasing of the forward speed and rotational speed, expansion force increase, the proper forward speed is 2-5m/min, a suitable rotation speed is 200 r/min; 6. rotary compliant expansion is much less than the solid cone expansion in expanding force, the former is the latter's 1/4; 7.The laboratory expanding experiment shelf was established, effect relations is proved, and the result of theoretical analysis, simulation and experimental are quite close;8.The failure mode and influential factors in expansion process is analyzed in brief; 9. The expandable tubular's mechanical properties and metallographic are analyzed, when solid cone expands, the Material strength and hardness become big, Plastic Strength become small; when rotary compliant expands, the Material strength and hardness become small, Plastic Strength become big.In all, these conclusions will accelerate solid expandable tubular technology to be domestic and practical, raise geological exploration equipment and technology level, and lay a solid foundation for the further research.