Abstract
The critical technical issues for the structure design of three-roller tube expander were first studied and analysed in this paper. Then, the major design parameters of the expansion unit structure and the bearing limit of 12¼″ three-roller tube expander were optimized and investigated by finite-element numerical simulation method. Results from study show that the required expansion force increases when the taper angle of the roller outer surface gets larger, taking the axial expansion force as the quantitative indicators. It is suggested that the roller tape angle of the expansion unit should be in the range of 9–12° considering the proper length of the roller and the non-self-locking tube expansion process. The required expansion force of the bellows first decreases and then increases when the gauge length of the expansion unit becomes longer. The optimal value of the gauge length is 50 mm considering the proper length of the roller. And according to the numerical simulation results, the designed three-roller tube expander meets the strength requirements. The results of this study are of great significance to the expend bellows drilling technology.
Highlights
The oil and gas exploration and development in China is gradually developing towards offshore deep drilling
The technology of equal-diameter isolation of complex well segments by expandable bellows is to roll the circular tube, of which the inner diameter is larger than the borehole diameter, into a bellows with diameter smaller than the borehole diameter according to the metal plastic deformation
The major design parameters and key parts of the expansion unit structure of 121⁄400 three-roller tube expander were optimized by theoretical analysis and finite-element numerical simulation method
Summary
The oil and gas exploration and development in China is gradually developing towards offshore deep drilling. If the tool structure design is unreasonable, the bellows may be damaged in the process of expansion and the expansion operation cannot be completed. It may result in some severe drilling accidents. The bellows has certain ovality after hydraulic expansion, so the bellows is trimmed to the corresponding borehole size of the drill bit by three-roller expander. In this paper, according to the function requirement of expansion tools in the mechanical expansion process of bellows, the key issues of the structure design of three-roller tube expander are studied. The major design parameters and key parts of the expansion unit structure of 121⁄400 three-roller tube expander were optimized by theoretical analysis and finite-element numerical simulation method. The three-roller tube expander can be used in the field of coil-wound heat exchangers [12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
