Alyeska's smart pig run is successful despite challenges

Alyeska’s Integrity Management team recently overcame low throughput challenges to complete a successful 800 mile run with a sophisticated Inline Inspection Tool (ILI), also known as a smart pig.

Currently, a smart pig is run every three years to inspect for the threat of corrosion, dents, and pipeline movement. TAPS is inspected in two pig run segments. The northern run from Pump Station 1 to Pump Station 4 (144 miles) takes 2.5 days and the southern run from Pump Station 4 to Valdez (656 miles) takes 12.5 days. The southern segment is one of the largest pipe wall surface areas in the world to be inspected by a smart pig.

The smart pig, also known as an Inline Inspection Tool (ILI), used for this year’s run utilized three measurement technologies (corrosion, dent, and movement) on one tool. This type of ILI tool, known as a “combo” tool, eliminates the need to make more than one pig run per segment. The three datasets from this inspection will be used by the integrity management team to locate, prioritize, and investigate pipeline features that may need repair or remediation.

The primary challenge to this year’s pig run was preparing the line for inspection. Inline inspection tools work best in a clean pipeline. As throughput decreases and the oil cools, it becomes more difficult to clean wax from the pipeline walls. Cleaning pigs were run on 4 day increments for one month preceding the ILI run. Another feat that must be accomplished during the ILI run is the lifting and lowering of every check valve clapper to allow the ILI tool to pass without damage.

Despite these challenges, both runs were successful--thanks, in no small part, to the tremendous teamwork of Alyeska employees and contractors across the organization.