Analysis of Tubing Collapse Failure during the Operation of blending light dropping viscosity

The heavy oil is the key point which China develops, at present the heavy oil is produced using the technique of blending light dropping viscosity, in addition to usual tubing failure ( pull out, fracture, perforation, corrosion etc.), a new failure form appeared that is tubing collapse, especially in western oilfields China. For the tubing collapse failure in heavy oil recovery well, this paper used the method which the experiment and the theory unify to launch on the analysis research, and mainly considered and analyzed tubing collapse strength under two kind of operating condition according to the field operation situation. This paper pointed out that should consider the bending effect in the pipe string design and the field operation, and must carry on the preliminary calculation to the anti-extrusion pressure in front of the field operation, in order to control the biggest anti-extrusion pressure in the annulus.