Recommended Doping Procedure for Casing/Tubing Connections

Compound Preparation and Contamination:

Upon opening the container, the product should be stirred with either a dope brush or other suitable device to re-blend any oil separation or settling of the component solids that may have occurred during shipment and storage. Care should be taken that after opening the container, no contamination of the compound in the container occurs, i.e. drilling fluids, water, dirt and other debris. In no instance should any material such as diesel fuel, kerosene, motor oil, etc. be added to the compound to improve the ease of application. Contamination or adulteration can change the friction factor / torque factor of the compound and also degrade the galling resistance properties.

Connection Surface Preparation:

Tube Mill, Threading, Inspection and Pipe yard Operations: Connection surfaces should be free of moisture and contaminants (including storage compounds) prior to the application of thread compound, whether it is intended for storage only or also as a ?running? compound. All corrosion effects are the result of an electrolytic process that requires both water and dissolved ions (chlorides, sulfides, sulfates, and other dissolved ions) to serve together as an electrolyte. Most corrosion inhibitors are ?surface active?, meaning that these active molecules will attach themselves to the metal surfaces preventing access by the contaminants that cause corrosion. If those contaminants are present on the threaded surface prior to application of the thread/storage compound, they will be trapped against the surface and corrosion will occur. Simply drying the surface with compressed air will not be sufficient. When the moisture evaporates, any dissolved contaminants will remain on the surface. To remove moisture and contaminants, a de-watering fluid/corrosion inhibitor can be applied to threaded surfaces. Immediately prior to compound application, any excess de-watering fluid/corrosion inhibitor on threaded surfaces should be removed.

Running Offshore: All tubular connections should be thoroughly cleaned (including removal of storage compound) and dried at the rig prior to inspection and application of thread compound. Care must also be taken to ensure that the cleaning process does not cause environmental pollution.

Compound Application:

After the connection is clean and dry, inspect and remove any brush bristles left on the threads/seals from cleaning process. Apply a light, even coating of thread compound over the entire thread and seal areas of the pin and box, leaving the thread form clearly visible. The practice of slapping a ?gob? of pipe dope on one side of the pin or box and depending on the pipe rotation during make-up to distribute the compound over the connection surface, is not sufficient. The compound must be worked into the thread roots and should completely cover the entire thread and seal areas of the pin and box. If the pins are doped when the pipe is on a rack, care should be taken to ensure that when the string is stood up on the rig floor prior to running, that the compound does not pick up contaminants (e.g. dried mud, cuttings, etc.) off the rig floor. Ideally, protectors should be installed on the pins after doping and then removed just prior to stabbing on the rig floor.

Good handling, cleaning and thread compound application procedures are key elements for a successful make-up job.