Vacuum Insulated Tubing Steam injection is the development of heavy oil resource economic effective method. In order to reduce heat loss of steam injection process and protect casing, usually by Vacuum Insulated Tubing(VIT) which generally uses double concentric tube, in the two layers of annulus inside pack insulation materials, and the pipe ends sealed to ensure good insulating properties. Function of Pre-Stressed Vacuum Insulated Tubing 1. Reduce the heat loss, certainly the steam quality and the depth of steam injection can be increased. 2. Minimizes heat stress on casing and cement mantle, protect the casing from damage by high temperature. 3. During oil production it will provide superior insulation and greatly reduce the loss of heat energy. Character of Pre-Stressed Vacuum Insulated Tubing 1. The pre-stress will compensate the tubing expansion caused by temperature difference between the inner and the outer tubes so as to ensure reliable operation under high temp. 2. Gas absorbing materials are packed inside the annulus to clean up harmful gas and maintain good insulating property whilst in service. 3. Integrated application of heat insulation technology, contains vacuum, heat reflection, heat convection block, ensure super heat insulation performance of the insulated tubing. We have passed the API Q1 and API 5CT certification. Technology parameter: