1. Technical background

  ■ With the development technologies in deep/horizontal wells and large-scale development of natural gas, higher requirement for sealing performance of tubing and casing is up to the surface.
 ■ To minimize the potential risk of the accident due to leakage of premium connections, helium detection has become mandatory requirement in most oilfields in North America, Mexico and South America.

  2. Solution
Machining tolerance, collision in transportation and tiny corrosion, improperly pipe dealing and repeatedly using may cause failure of premium connection of tubing and casing in HP gas well. Hence, periodically detection of the sealing performance of premium connection is necessary to avoid potential hazards.

 3. Technical principle
As helium molecular diameter is small and it is easy to penetrate in the premium connection threads. By this feature the sealing performance of the connection of tubing and casing can be more sensitive to be detected.

4. Detection process
The twin-packer testing tool runs into the pipe string first and then the packer will be set by injection of helium and nitrogen gas mixture. Then pressure will rise to the specified value and be held for a certain time. After releasing the pressure, a high-sensitive helium gas detector will attach to the helium basket to detect if there is  leakage out of the connection..

   5. Technical features
■ 90％N2+10%He as  testing medium.
■ Helium gas is inert gas, innoxious <app:innoxious>, safe to be handled and non-corrosive to tubing and casing.
■ Fast operation, 1.5 minutes for each connection, and small impaction on the tripping time.
■ Range of detected pipes:¾in~20in(19~508mm.
                               ■ Sensitivity of the detector for helium gas is 5ppm.