The installation and construction method of pipeline system in ultra-deep vertical shaft of underground cavern

In a certain national petroleum reserve cavern, there are eight oil inputting and outputting vertical shafts which are over 100 m deep. The pipeline system is successfully installed and constructed in the ultra-deep vertical shafts by means of sectional pipeline prefabrication on the ground, pipeline installation followed by installation of steel support and anchor ring. In this paper, the features of this construction method were introduced. And the key construction techniques were discussed, e.g. sectional pipeline prefabrication, visual precise positioning based on X-ray machine, manufacture of steel truss and basket system, and preparation of yoke-style assistant platform. The main procedures include construction preparation, installation of wellhead system and accessories, sectional pipeline prefabrication, installation of pipeline in vertical shaft, manufacture and installation of steel truss and basket system, installation of steel support in vertical shaft, anticorrosion work in vertical shaft, installation of pump block at the bottom, and pipeline pressure test. By virtue of this method, the lifting of pipeline into shaft is free of the effect of steel support, the aerial workload and its potential safety hazard are reduced, the construction cost is cut down, and the installation efficiency is overall improved.