ABSTRACT
Hostile environments found in deep, high pressure gas wells require that extra precaution be taken to extend the productive life of the well These measures often result in the use of corrosion resistant alloys (CRA's) to prevent premature failure of the production tubing due to severe corrosive action on carbon steels.
This paper discusses a new technology that employs a new running procedure for CRA tubulars. The procedure eliminates ALL die penetration marks (slip, elevator, and power tong) created during conventional make up of a tubular connection and installation of the tubing string in the well. This procedure uses a number of new and innovative devices and relies on supporting the tubing string weight on the face of the coupling. In addition, the string is lowered into the well with the use of lift subs around which the elevators are latched. The connections are made up with specially built power tongs that employ new technology for gripping both the tubular body and coupling O.D.
A brief background of the design criteria for the tubing string is presented along with expected installation environment data. The history of the development of the procedure is discussed and the testing program to prove the feasibility of the procedure is detailed. The resulting data and actual performance of the CLS Running Procedure in a case study clearly demonstrates the potential for cost savings.
The cost savings is realized by reducing the wall thickness of CRA tubulars. It accomplishes this by using design criteria based on well environment conditions only. The need for increased wall thickness to compensate for a decrease in the cross-sectional area (due to die penetrations) is eliminated.
