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Hilcorp seismic still on
Federal shutdown delayed permits for Cook Inlet work, which will now begin in May
Steve Sutherlin for Petroleum News
Hilcorp’s 2019 offshore seismic program planned for federal waters 20 miles due west of Homer in lower Cook Inlet has been delayed by last year’s federal government shutdown, but it has not been canceled, the company said.
The new projected start date is May 3, Mike Dunn, Hilcorp development manager said in remarks to the Alaska Support Industry Alliance luncheon in Kenai March 15.
“We were intending to start shooting the seismic in mid-April, in fact, our seismic vessel is coming up from southeast Asia; it’s going to be here April 18 and we will have to pay probably two weeks of standby at a pretty high price waiting on those permits,” Dunn said. “We started this process first quarter last year and in December they were expected to publish those permits.”
Instead, the comment periods for two key federal permits is expected to begin in late March.
“We were supposed to have (the permits issued) early April; the five-week shutdown really stopped everything,” he said. “April may probably be the best time to shoot a seismic program in lower Cook Inlet; it slipped a few weeks but we expect to be out of there by early June.”
Dunn said the notorious Cook Inlet currents are not as challenging in lower Cook Inlet as they are to the north.
“If all were to go perfect, we’ll be running about three lines per day; there’s about 90 lines; we should be able to finish in 35 days,” he said. “We’ve got some contingency, there will be some tangles, but the tides are not quite as bad down here as they are in the upper Cook Inlet.”
With anticipated contingencies the entire shoot is likely to take 40 or 45 days, Dunn said.
The company is hopeful the seismic results will lead to the drilling of exploration wells in 2020, Dunn said.
It’s certain, however, that Hilcorp will not use either of the jack-up rigs currently positioned in Cook Inlet should it proceed with drilling the prospect.
“The deepest water in that area is about 280 feet; you get to the edges, I want to say it’s at least 180 to 190 feet of water,” Dunn said. “A 300-foot jack-up rig will be able to drill the wells.”
Both the Spartan 151 and the Randolph Yost jack-up rigs - now in Cook Inlet - are limited to a maximum water depth of 150 feet.
The cost of mobilizing a 300-foot jack-up rig to Alaska will raise the bar in terms of the quality of the targets the company must have to justify exploration drilling in the survey area.
“This whole program, including getting the permits, and shooting the seismic, is about $15 million,” Dunn said. “Hilcorp is paying 100 percent of that and we hope to get some partners to help us drill some wells if we do identify some prospects.
“If we make some discoveries, we will do an environmental impact statement and hopefully set a couple of platforms,” he said.
Sound source verification Hilcorp is hopeful that a sound source survey planned for the first two days of the operation will indicate a tighter radius of potential disruption to marine life than that of earlier seismic work in Cook Inlet.
The sound source survey will measure and monitor the sound and the distance from the source that whales or other marine mammals can hear it, Dunn said, adding that the percussion generated by the 2019 survey will be softer than that used in a recent 3-D survey in Cook Inlet by Apache.
“I think it’s about a third less decibel levels, so we’re going to run the source with recorders down on the sea floor to measure and we’ll be able to plot the sound and the dissipation of sound,” he said. “We think that we’ll reduce the area from about a seven-mile radius to about four or five miles.
“When we talk about decibels, it’s different in water than it is in air, so when we talk about 80 or 120 decibels, this is the underwater noise (marine mammal disturbance level) that is the equivalent of about 30 decibels in the air,” Dunn said. “So it’s not that loud; in water, that pressure wave acts differently.”
During seismic operations a nine-member crew of protected species observers will be on duty - five on the seismic vessel, two on one of the support vessels, and two on the helicopters that will go up every day, Dunn said.
“They’re going up to look for primarily beluga whales or other mammals in the area, note them, and if they get to that radius, that seven- or five-mile radius, then we’ve got procedures for shutting down the seismic until they leave that area,” Dunn said. “This is required in all areas where there are protected species.”
April arrival The seismic vessel will re-provision March 18 in a southeast Asian port for its voyage to Alaska, arriving Homer on April 18 or 19 for a day-and-a-half-long call, Dunn said.
“They’re going to swap out crew members and get groceries and that sort of thing, and it will set sail and it will anchor up probably around the point from Seldovia until the shoot,” he said.
Dunn said Hilcorp has contracted with Polarcus Ltd. for one of its unique state-of-the-art purpose-built seismic vessels, which are independently certified for environmental efficiency.
“These are all diesel electric propulsion; they use low sulfur diesel,” he said. “It’s about 310 feet long and it has the most advanced seismic technology available.”
Polarcus received the world’s first-ever DNV GL Level 1 Triple-E rating, the company said in a November 2012 news release.
“Triple-E is a voluntary environmental rating scheme for ships with a rating from Level 4 to Level 1, where 1 is the highest,” the company said. “To achieve Level 1, all levels must be complied with and there are areas of compliance within management, operation and design.”
The rating is based on a verification of a ship’s actual energy efficiency and environmental performance, with key elements being energy efficient operation as part of policies, action plans and daily operations; energy efficient ship design; and verifiable monitoring, measurements and documentation schemes, Polarcus said.
“These vessels are booked months, to a year in advance,” Dunn said. “So we booked it about six months ago and we tried to find that window that would work best.”
Survey array The Polarcus vessels tow a survey array which emanates sound pulse roughly every five seconds, Dunn said, adding, “It goes down to the seafloor and goes into the earth, and its tuned to look primarily at a depth between 300 feet and 12,000 feet.”
Trailing behind the sound pulse source, eight streamers receive the returning vibrations.
“The distance from the boat to the end of the streamer is 2,400 meters, or about 1.3 nautical miles,” Dunn said.
“They create a map - in three dimensions - of what the subsurface looks like, and based on the structure, the depths, and how thick we think the sandstones are then our geophysicists and geologists will draw a map and we’ll (calculate) the chance factor of there being oil enough to do a commercial discovery, and then we run economics,” Dunn said. “The first stage is to create these maps.
“The vessel will have a maximum speed while it’s running the survey of about four-and-one-half knots,” he said. “It will take four to 10 hours per 16-mile line length depending on whether the tide is with you or against you.”
Hilcorp geologists have some idea of what to expect from the survey.
“Our geologists have identified some structures from very old seismic and the idea is to create much better maps with much better resolution that have depths and even perhaps some thickness of sands so that we can put together a plan to drill the wells,” Dunn said.
Dunn said that in the early 1980s Marathon and ARCO drilled in the area, adding, “We have one well to tie the results into.
“The seismic technology has improved immensely, both in minimizing the environmental impact of the vessels - how they’re designed and built; and then the quality of the data that we are able to get and hopefully drill some wells,” Dunn said.
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