Integrity Analysis Of Completion Tubing Strings In High Angle And High Production Gas Wells And Technology To Control Research

The premium threaded connection with gas seals and permanent-type packer are used for completion tubing strings in high angle and high production (HAHP)gas well.The integrity of the completion tubing string consists of two parts:the basis of ensuring tubing not be destroyed and adequate strength so that ensuring the safety of tubing; the other problem is the sealing of strings that guarantee the tubing does not leak. Specific researches includes the following sections:Firstly, considering of the situation that the tubing weight, internal pressure, external pressure, friction and the piston forces, based on classical mechanics strings theory, to analyse the buckling of highly deviated well completion tubing strings,given the buckling equation and the critical buckling load of the tubing in vertical, slant, curved and horizontal well borehole.On this basis, checking to the tubing axial deformation, load and stress calculation method of the former, provide the basis for pipe strings design and a reasonable choice of production parameters.Secondly, analyse the packer rubber tube deformation stress in three stages of the high angle high-yield gas well completion tubing strings. Derived plastic tube with wallface contact force formula at different stages, according to the model of the packer bite into the casing, the casing stress has also been discussed. Acute vibration of downhole strings will made packer sealed tube prolapse cavity, or damage to the casing, packer, test valves and wellhead equipment, etc. Therefore, this article on the basis of strings vibration, unlike previous studies, instead, put the entire tubing sting as a system, analyse the lateral vibration of tubing under multi-point contact circumstances, and three vibration reduction measures has been proposed.Using the ANSYS finite element software, consider about the different conditions which applied different loads, to analyse pipe thread joints'force, given the stress, displacement and contact pressure distribution of the special threaded joint.Then, combine the theory of tubing mechanical and experimental research, using the underground load tester to test in the Daqing oil wells, obtained the underground tubing strings load, pressure, temperature curve in different conditions, and compared with the theoretical results, calculated and measured values'maximum relative error is less. The result is important to guide oil field operations.Finally, using specific examples to analyse the completion control technology of the HAHP gas well tubing, gives the related recommendations to ensure tubing integrity.