Vacuum insulated tubular has various forms to meet the needs of different oil well conditions. It can be divided into three types according to the end connection mode: external connection, internal connection, and direct connection.
Vacuum Insulated Tubing & Casing is one of the necessary downhole tools for steam injection to recover heavy oil.
1). Use insulated tubing to inject high dryness steam.
2). Promote more heat into the oil layer to ensure the dryness of steam.
3). Prevent deformation and damage of well casing and cement ring due to high temperature, and improve casing service life.
4). Implementation standard: SY/T 5324-2013 Prestressed insulated tubing.

External Connection Vacuum Insulated Tubing & Casing
As the most popular types of Vacuum insulated Tubing and casing, the external connection has proven technique and easily accepted by end-users. The connection is located on an external pipe, exactly like regular tubing and casing. There are two coupling options. One is regular couplings with an insulated sleeve and the other is vacuum insulated coupling. The external connection Vacuum insulated tubular has the following advantages:
1.Connections on outer pipes.
2.With Regular couplings.
3.Insulation inserts ( PTFE or graphene ).
4.Inner pipe connects each other, no thermal loss area

When the insulated tubing is in use, an extendable graphite sleeve is installed between the tubing and within the coupling. The heat graphite sleeve is made of metal housing and heat insulation material, with good rigidity, which can effectively reduce the heat loss at the coupling.