VIT Buyers Guide

Respecting your right to make your own decisions we offer verifiable facts , specifications, and technical documentation to help Buyers and Petroleum Engineers make a comparison between the different manufactures of VIT. We provide five (5) important specifications and manufacturing procedures decisions makers might use the evaluate the technical qualifications of each manufacturer. Qualification statements for OTSI ThermalTube 3H are listed.

Qualification Detail OTSI
Bake-Out (Temperature Programmed Desorption Cycle): This is a 15-24 hour process whereby a completely assembled joint of VIT is placed into an oven and baked at increasing temperatures over time to desorb and mechanically pump gas molecules trapped in the matrix structure of the steel inner and outer tubing. Yes
Controlled activation of Getter: A general requirement for Getters materials is the activation in a vacuum having a pressure below 1-Torr.  The reason is to avoid contamination of the Getter surface and the chance of forming a new Passivation layer blocking the sorption of gas molecules. If Getter is field activated the VIT manufacturer should provide technical detail confirming how <1-Torr annulus pressure is guaranteed when Getter is activated. Yes
Activation at less than 10-15 Milli-Torr (0.01 to 0.015 Torr)
Quantity of Getter installed into each joint: Getters have a finite capacity for sorbing gas molecules. Buyers should ask each manufacturer the quantity of Getter in each joint. If there has been no Bake-out then substantially higher Getter quantities are required.


(This is proprietary information and OTSI will provide these quantities upon request and with agreement for non-disclosure)

Number of Radiation Barriers: In a steam injection well, heat transfer is by radiation, conduction and convection.  Radiation alone accounts for about 85% of the heat losses from well head to the casing, cement and formation.  The VIT insulation system is optimized with multiple reflective barriers having each barrier separated by an insulating material. The Buyer should know the number of reflective barriers used by the manufacturer. Yes
(7-layers of AL foil each separated by ceramic paper or fiberglass cloth plus shinny OD of inner tube, shinny ID of outer tube and High Build Aluminum paint on the OD of the outer tube.)
Qualification of Raw Materials for Vacuum Service: The manufacturer should provide the technical data sheet to confirm multilayered insulation system raw materials are manufactured for vacuum duty. Yes
(Data Sheets upon request with agreement for non-disclosure)