"Disappearing" plugs leave full inner diameter
Total Catcher Offshore AS of Bergen, Norway, has developed a series of new plugs for the offshore industry. The plugs have undergone qualifying tests, been installed, and used at some Statoil fields in the North Sea with good results. The company is now manufacturing the plugs for use worldwide.
The Tubing Disappearing Plug (TDP) runs the completion string, sets the production packer, and allows several pressure tests before "disappearing" the plug without any wireline. Both Statoil and Norsk Hydro are partners in the TDP project.
The TDP is installed in a pup joint and runs integrated in the completion string or liner. The firing mechanism is based on a pyrotechnic system and activated by hydraulic pressure. Alternatively, a timer-based system is also available to activate the firing device. Once the TDP has disappeared, the material disintegrates leaving full inner diameter through the tubular. As back-up, the plug can be mechanically opened with a wireline TCO emergency shoot-down tool. The plug enables predetermination of pressure cycle capability and holds differential pressure from above and below. The number of cycles required by the customer is pre-programmed into the filing system, and the last cycle sets off an explosive charge disintegrating the plug. The activating system is typically set to fire after 8-12 cycles.
The Tubing Disappearing Smart Plug (TDSP) is a spin-off of the TDP. It has the electronics and firing system integrated in the wall section of the carrier. Once the system has fired, the glass plug disintegrates into sand-like particles, and the electronics remain protected in the wall section, leaving a full bore for later interventions. The system can be run "upside down" in cases where debris settling is a concern or even as a combination with the standard hydraulic actuation system on top and the timer-based firing system below as a contingency. The Intervention Disappearing Smart Plug (IDSP) is a temporary barrier system. The IDSP can act as a pressure barrier during work in the well and can be installed in the well with standard setting tools on wireline or pipe. The IDSP has the same firing systems and glass plug technology as TDP and TDSP. IDSP can be removed with wire or pipe after use if required.
