Texan engineers develop a permanently seabed-based pigger
Engineers at Texan firm NOV are developing a pigging machine that can be permanently installed on the sea bed. The Subsea Automatic Pig Launcher (SAPL), can be operated remotely, has an internal cassette capable of holding up to 10 pigs, while a ROV-operated ball valve barrier enables deployment with no disruption to production. NOV is building a prototype off the west coast of Norway, and expects tests to be completed during Q1 2018. It is also examining an all-electric version of the SAPL.
Subsea field design involves a lot of time spent weighing options and considering the costs and benefits of various technologies.

If a production line is likely to require frequent pigging, for example, a twin pipeline, or loop system, may be justified. But the cost to build and install a second pipeline is significant, especially in very long subsea tie-back developments.

Subsea pig launchers enable pigging with a single pipeline. The downside is that they must be deployed and retrieved with a vessel and remotely operated vehicle (ROV), which is costly — and time-consuming if the pigging operation is not part of a scheduled maintenance programme.