4PIPE-HIDROPIG Plugs for pigging: The best way for cleaning flexible pipelines

Authors: Mateus Nobeschi & Sergio Furtado

In recent years, Oil & Gas Operators have been facing challenges in terms of flushing and cleaning flexible pipelines. For decommissioning programs to reuse or to dispose of those pipelines, oil deposited onto the riser can be a big issue:

1. When decommissioning, generally in reels, the flushing and cleaning is challenging due to the pipeline arrangement. Being a robust system, the installation of an ASME standard launcher and receiver becomes difficult and slow. The flange patterns also needs to be considered.

2. In cases where the flexibles do not have a flange, that is, with cut ends, the operator can prepare them but must take into account the removal of the external coating until the arrival of the steel casing to proceed with any welding work.

3. When cutting, the end of the pipe could be easily damaged, ovality and minor kneading can be caused. Due to operational time constraints repairs are often overlooked and not undertaken. In this case if the final end of the flexible wasn’t recovered it would make the installation of equipment more complex.

4. When the flexibles are reeled, in large diameters, that is, above 9", installing an ASME standard launcher or receiver becomes extremely difficult for numerous reasons; ground differences, system support, operationalization, among others.

Searching for a solution to these problems, the equipment is designed by IK-Norway and then manufactured, tested and qualified by 4Pipe-Hidropig to suit nominal diameters of; 2.1/2’’, 3’’, 4’’, 6’’, 7’’, 8’’, 9.1/8’’, 9.5’’, 10’’, 11’’, 12’’ & 14.1/2’’ - with capability to adapt the solution for further sizes.

The project itself was a success in all aspects: every trial was performed as planned and the end users were satisfied with results of the operation in terms of safety and efficiency.

By using this system, we achieved a significant improvement in terms of time optimization; achieving a 75% reduction in the entire process and set-up operations.

After the initial client used the device, we were able to demonstrate the operational efficiencies and functionality leading to implementation of the application by other end users in Brazil.

The system works by torquing up the equipment (with defined torque) to seal the flexpipe ID and pressurizing it for launching, not exceeding 150# (10,3 bar or 1,03 Mpa). The “packer’’ material used for sealing, is made of polyurethane, and is designed using 4Pipe-Hidropig ‘know-how’.

The body of device is projected to resist impact and with high yield limit. The only part that needs to be changed (after multiple uses) is the polyurethane packer.

Nominal diameters tested and proven operationally: 2.1/2’’, 3’’, 4’’, 6’’, 7’’, 8’’, 9.1/8’’, 9.5’’, 10’’, 11’’, 12’’ & 14.1/2’’.

Total assembly (fit-in pipe and start pressurizing) of equipment takes, in diameters of 2.1/2 ‘’ – 6’’, less than 8 minutes. In diameters of 7’’ – 14.1/2’’, takes less than 20 minutes (more time due to increased weight).