Cost reduction has been a strong tendency in the petroleum industry recently, annually millions of tons tubing is abandoned in China, leading to a huge resource waste. Based on self- propagating high temperature synthesis, abandoned tubing could be remanufactured functionally equivalent and visually indistinguishable compared to a new one, its field application has been launched in the oilfields and significant economic benefits was secured.
This paper presented three parts, first the three-dimensional finite element model was employed to study the maximum stress and residual strength of abandoned tubing corresponding to its wearing depth, failure criterion for abandoned tubing was established; second the alumina ceramic layer was prepared at the inner-wall surface of abandoned tubing based on self-propagating high temperature synthesis and the ceramic-lined composite tubing was obtained, the microstructure, corrosion resistance, mechanical properties and bonding capacity of the remanufactured tubing were evaluated, and finally the field operation of remanufactured tubing in harsh downhole environment was summarized.
The results indicated that the abandoned tubing must meet the requirement of certain criteria before being subjected to remanufacturing technique, that is 1.5mm for the J55 tubing and 2.8mm for the N80 tubing respectively; the bonding force between the steel pipe and alumina ceramic layer was more than 30MPa, the maximum impact energy was 73J, the maximum bending radius was 11m, making the remanufactured tubing capable of working in the harsh downhole environment, field application demonstrated its values, the popularization of remanufactured tubing in the oilfield is taking place.
This paper contributes to better understand the remanufacturing engineering in the perspective of petroleum industry, through the pioneering example and profound insights we are able to explore new horizons and yield more benefits to the long term healthy development of petroleum equipment.