Special Report: New launching technology increases pigging efficiency

A new technology allows multiple pig launching with existing pipeline equipment.

Aging pipeline networks and the installation of new lines over greater distances and in more hostile environments have heightened demand for pigging technology. Pipeline pigging is essential for removing debris and collecting sample fluids, ensuring flow is maintained and corrosion minimized. Pigging, however, is time consuming and can disrupt production and operational efficiency.

The UK oil Industry's Technology Facilitator issued a call for technology proposals to increase production capacity and efficiency. Participants identified reliable flow-assurance techniques as critical. This article details field testing of a technology developed by Pipeline Engineering & Supply Co. Ltd. in response to the ITF's call for proposals.

AMPL

The Automatic Multiple Pig Launching System is a new multipigging tool designed by PE. It uses existing pipeline equipment, retrofitted with a cassette loaded with independently launchable pigs. AMPL requires neither modification to existing pipeline launchers nor an external power supply.

Existing automatic pig launchers generally operate a complex arrangement of kicker lines and valves or release flaps for multiple launching. The latter mechanism cannot be retrofitted to existing traps and often requires an external power supply. The complexity of the design can also add substantially to the cost of a launcher.

Opening a trap closure also has health, safety, and environmental implications. These issues become even more complex when pigging from an unmanned platform or during a remote subsea operation. Mechanisms built into the pigs rather than the launcher control pig launching by AMPL, negating the need for human intervention and reducing the intensity and risk of regular pigging activities.

ITF worked with PE to secure industry support from four of its member companies for an AMPL Joint Industry Project to be carried out in two phases. Following successful completion of Phase 1, PE secured further support for two sets of field trials to assess the overall system performance and functionality and gain further understanding of the bypass systems on individual AMPL tools.

JIP participants used a 10-in. AMPL system for the first set of field trials, recently completed at the Petrofac facility in Montrose, Scotland. These trials successfully launched and received the AMPL pigs at flow velocities of 0.5 m/sec and 1 m/sec (14,000 and 28,000 b/d, respectively). The pigs launched successfully and confirmed tests previously undertaken at PE's North Yorkshire base to test and validate AMPL's setup before mobilization to the Montrose base.

Montrose test

The AMPL system cassette was loaded with three suitably configured pigs. Earlier flow tests had shown this configuration to be successful at launching individual pigs with the fluid flow rate set to 0.5 m/sec. Fig. 1 shows data produced from this multiple launch test.