Legendary diver recounts Cook Inlet dangers when now-leaking gas line was installed

Historic footage and the recollections of a legendary commercial diver highlight the challenges Hilcorp Alaska faces as it dispatches divers to patch one of its undersea pipelines.

Owen Boyle, a Cook Inlet construction diver for four decades until 2004, helped install the original platforms and pipelines in Cook Inlet as the basin became a major oil and gas province in the mid-1960s. Boyle said the basin is the most dangerous place in North America for commercial diving, with its black water and some of the world's strongest tides.

Boyle, now 85, is one of two divers inducted this year into the Commercial Diving Hall of Fame of Houston, Texas. Last summer, he published a memoir about his Cook Inlet career, "Diving Blind into Danger."

[Antiquated Cook Inlet pipelines targeted amid busy season for oil and gas leaks]

Boyle helped install in 1965 the pipeline that's now leaking Hilcorp's natural gas northwest of Nikiski, where he lives. It was the first pipeline installed in Cook Inlet, extending 7 miles from the coast to the first offshore oil field and platform in Alaska. Boyle returned to inspect or repair that steel, 8-inch pipeline many times over the years.

"We had to take good care of that pipe. We knew it was vulnerable," Boyle said.

The Inlet's powerful winds and tides complicated the pipeline installation from the outset, according to an original, 13-minute documentary of the undertaking, posted to YouTube by the nonprofit watchdog Cook Inletkeeper.

The feat helped pioneer modern oil and gas development in rugged Alaska, inviting comparisons to Shell's more recent effort to crack open the U.S. Arctic Ocean to development.

But where Shell failed in the Arctic, abandoning its exploration there in 2015, Shell and several other companies found success in the early days in Cook Inlet. Shell originally operated the first pipeline and Platform A in Cook Inlet's Middle Ground Shoal field. The company also produced the documentary.

"Oil has been found in Alaska, and now it must be brought to market," says the narrator, as winds howl and sea ice crunches against what appears to be a massive leg of the production platform built in 1964.

As the pipeline was lowered to the seafloor, Boyle and others made multiple dives to check its joints and make sure it wasn't damaged or sitting on rocks.

The pipe was guided to the bottom by a giant steel structure that acted like a ramp, extending into the water off the end of a barge. At 400 feet long and weighing 140 tons, that steel structure was "the biggest piece of construction equipment ever fabricated in Alaska," the documentary said.

[Hilcorp finds 2-inch gash in leaking natural-gas line in Cook Inlet]

The pipe slid down beside a twin backup pipeline. Either could be operated if the other line failed and couldn't be repaired until winter ended, the film shows.

The now-leaking pipeline initially carried crude oil but was later converted to ship natural gas as fuel.

The gas leak, from a pipe about 80 feet underwater, was discovered Feb. 7 as surface water roiled, though data shows it began in December.

Fixing the pipeline won't be an easy job for divers.

"The treacherous tidal currents and the black, zero visibility water create extreme diving hazards," said a description for Boyle's book on Amazon. "No diver has ever been killed in Cook Inlet, but there have been a lot of close calls."

Jobs have to be done blindly in Cook Inlet, even dangerous ones such as cutting metal with a torch during salvage operations, Boyle said. Divers need a "good feel for things," along with diving partners and support crew to keep them safe, Boyle said.

The diving is especially difficult north of the forelands where the Platform A pipe is located. The Inlet narrows significantly at the forelands, and the tide runs faster there than farther south. Rivers there also contribute lots of dirty glacial silt, Boyle said.

Boyle remembers a time during the pipeline installation when a strong tide turned the barge sideways as pipe was being placed in the water, putting pressure on the pipe.

Every available tugboat sped to the rescue, "pushing on each side and pulling on the other side" to keep the barge straight, he said.

"It saved the pipeline," he said. But that section ended up with a "long, gentle curve," and some of its protective concrete coating cracked off, he said.

Divers checked the pipeline and found it to be "acceptable" for use. Is that where the gas leak is? Boyle said he doesn't know.

The 1965 documentary depicts one such action-packed day, when multiple tugs fight stiff winds and currents to restrain the barge.

The film touts the pipe's engineering. The walls were built "twice as thick as normal" and coated with an inch of concrete. A concrete spiral rib encircled the pipe — research had showed it could reduce the "high-frequency vibrations caused by the currents," the film's narrator said.

Despite those steps, later pipes installed in the Inlet were even "thicker and stouter, with more coating" to protect them, Boyle said.

Boyle spent about the last 15 years of his career working for American Marine Corp. — the company preparing to repair the gas leak for Hilcorp.

"They'll fix it," Boyle said, citing the company's strong safety standards.

Until he quit diving, Boyle's work protecting the pipe often involved placing sandbags around lengthy stretches of pipeline that weren't supported by the seafloor, stabilizing it against vibrations in the strong tidal currents.

"It did a lot to save the pipe," he said. "It's worked a long time."

Swaths of unsupported pipe are threatened by turbulence and could grind against rocks in Cook Inlet, the U.S. Pipeline and Hazardous Materials Safety Administration said in its response to the leak.

Hilcorp Alaska reported Monday that inspection dives had begun over the weekend. They said divers located a 2-inch gash at the bottom of the pipeline, atop a boulder embedded in the seafloor. Divers were taking steps to install a temporary repair clamp.

Rock abrasion at unsupported sections was blamed for two leaks in the gas line in summer 2014, prompting repairs by former pipeline owner XTO Energy, the agency said.

"We did a pretty good job in early years inspecting that thing," Boyle said.

But "that tide keeps rolling things around," and new gaps open beneath the pipelines.

Boyle said he agrees with Hilcorp's decision that it was too dangerous to send down divers until temperatures warmed enough to clear the ice, as they did over the weekend.

"You can't put divers out there when the ice is running around," he said.