What’s Vacuum insulated tubing and casing
Vacuum insulated tubing and casing belongs to OCTG and now becomes significant to the exploitation of heavy oil.
Here is some introduction.
With the development of petroleum industry and the increase of petroleum consumption, the exploitation of heavy oil has become the main source of increased production for many oil companies at home and abroad.
There are two methods of heavy oil recovery: steam stimulation and steam flooding.
One kind of insulated pipe with heat insulation function used in heavy oil recovery during steam injection, that is Vacuum insulated tubing and casing, which also called VIT&VIC
Vacuum insulated tubing and casing has a double Pipe structure.
The annulus space between the inner and outer tubes is high vacuumed.
Vacuum insulated tubing and casing connects by couplings and insulated sleeve or donut or insulated coupling only.
The annulus space between the inner and outer tubes of the insulation tube needs to be filled with warped insulation material.
Thermal insulation materials need to be heated and dried to prevent the thermal performance and thermal service life of the thermal insulation pipe.
Conventional insulation material should at least include aluminum foil, mesh, fiberglass mesh, getter, and now new insulated material of aerogels, which are better insulated;
The sealing annulus is in a vacuum state, and the getter is placed inside, so as to clean the polluted gas and extend the service life of the heat insulation pipe.
The prestress compensation technology is adopted in the production of vacuum insulated tubing and casing, which can release the prestress when the inner pipe of the insulated tubing is affected by the steam heat, so as to compensate the temperature difference elongation of the inner pipe and outer pipe and ensure the reliability of the product at high temperature.
Prestressed Vacuum insulated tubing and casing can overcome the stretching deformation due to temperature change.
Its basic structure is composed of outer and inner tubes, between the two tubes are filled with heat insulation materials, such as perlite powder, ultra-fine glass cotton, argon, krypton gas, xenon gas, etc., the highest service temperature can be up to 400℃, the general heat insulation life can be up to 30 huff and huff cycles.
Prestressed Vacuum insulated tubing and casing has an inner connection, an outer connection, and a direct connection.
According to the requirements of the clearance, select the appropriate connection type of vacuum insulated tubing and casing to ensure oil recovery efficiency.
The three thermal insulation technologies of Vacuum insulated tubing and casing, thermal reflection and thermal convection blocking are comprehensively applied to create the super thermal insulation performance of thermal insulation tubing.
