Kaidu River Crossing in Korla-Shanshan Oil Pipeline

Kaidu River is a large river crossed by Korla-Shanshan Pipeline. Used in the project was the method of horizontal directional drilling, which is characterised by high construction speed, adequate depth of cover for pipeline, accurate location and low environmental impact. Described in this paper are the construction techniques and quality control measures. Preheating before welding was made to prevent microcracks. To prevent pipe coating from damage during back draging, American-made heat shrinkage sleeves were used, which are dedicated to the usage for directional drilling. Sample inspection, 100% x-ray and 100% ultrasonic examinations were made to guarantee welding quality. Joint coatings were inspected by means of high pressure pinhole, peeling test as well as visual examination. Finally, hydrostatic test was made.