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Sunday, July 25, 2010
Japan's 'seismic ship' may yield a bonanza
By EDAN CORKILL
Despite the ongoing Deepwater Horizon catastrophe in the Gulf of Mexico, the search for deep-sea oil and gas reserves elsewhere continues unabated — off the coasts of Scotland, Greenland, West Africa, Brazil, the Philippines . . . and even Japan.
As it lacks significant known commercially exploitable oil resources of its own, Japan has to look abroad to supply its considerable needs. Right now, indeed, the Japan Oil, Gas and Metals National Corporation (JOGMEC) and a host of private firms are involved in explorations the world over.
But this is no new phenomenon. A 1948 report prepared at the headquarters of the Allied Occupation forces noted that Japan's oil deposits are "lean, scattered and geologically complex." That assessment was echoed as recently as 2008 in an updated report by the American Energy Information Administration, which declared: "Japan has virtually no domestic oil or natural gas reserves."
Despite those two assertions, however, a lot has changed in the half-century between them with regard to the technology used to look for oil. Just as the telescope brought previously unknown wonders into man's field of vision, new oil-exploration technologies now have the potential to reveal previously unknown reservoirs within Japan's realm.
That's not to say Japan will suddenly find reserves of black gold beyond its wildest dreams, but — with the country relying on imported oil for around 50 percent of its total energy requirements — the government has decided to deploy those new technologies in the hope it might.
The plan for renewed oil exploration was given a formal framework in March last year, when the Ministry of Economy, Trade and Industry published its "plan on maritime energy and mineral resource development" — clearly signaling that its seas, rather than its land, would henceforth be the focus of attention.
According to the plan, "almost all" of the exploratory drilling that has taken place in Japan's waters to date has been in waters less than 300 meters deep.
The plan mentions wells in the Gulf of Mexico and off western Africa in asserting that new technology now makes possible exploratory drilling and oil extraction in waters up to 2,000 meters deep. (The Deepwater Horizon rig was operating in water 1.2-km deep, drilling to depths exceeding 10 km.) That means that all the sea areas between 300 and 2,000 meters deep within Japan's 4.4 million-sq.-km Economic Exclusion Zone are now accessible for exploration.
First, though, three-dimensional seismic surveys need to be conducted to determine if likely oil- or gas-bearing strata lie beneath the seabed. And even before METI published its plan last year, the government had started taking steps to bolster its seismic-surveying capabilities.
In February 2008, the government took delivery of a vessel that could conduct the most advanced type of three-dimensional seismic explorations. Bought from Norwegian oil prospectors Petroleum Geo-Services, the ship, formerly named Ramform Victory, cost ¥23.2 billion.
"There is no Japanese company with the ability to conduct three-dimensional geophysical surveys," the report states in justifying the purchase a year earlier. "And as there are so few such vessels in existence, it has become difficult to lease them when they are necessary."
The ship, renamed Shigen (meaning "Resource" in Japanese), is now on the front line of this new push to seek out domestic oil resources.
Like other seismic-survey ships, Shigen collects its data by shooting seismic waves down at the seabed from a so-called "air gun" it tows behind it. Those waves reflect off various layers in the Earth's crust and are collected by hydrophone sensors positioned on long cablelike "streamers" the ship also tows behind it.
Shigen's ability to tow up to 20 streamers allows it to collect highly complex readings from which detailed three-dimensional maps of the bedrock can be created.
Each of Shigen's streamers can be several kilometers long. In fact, in 2001, when the boat was being used for a survey project in the North Sea, it set the then-record for the largest "spread" of streamers ever as it hauled 16 cables with a combined length of 72 km. To tow all that cable, Shigen is fitted with two, 3,090-cu.-inch engines — the equivalent of eight long-haul coach buses.
According to the ministry's 2009 plan, Shigen will survey 5,000 sq. km each year between 2008, when it was purchased, and the end of 2011.
In a series of written answers to questions from The Japan Times, JOGMEC, which operates the boat, explained that it was slightly off-pace, having completed just 7,900 sq. km in its first two years of operation.
Areas searched so far include seas off the Sanriku coast in north-eastern Honshu, off Akita and Miyazaki prefectures, off the the Tokiwa region centered on Fukushima Prefecture, around Sado Island in Niigata Prefecture on the Sea of Japan, around the Ogasawara Islands south of Tokyo, around Tsushima off Nagasaki and around Okinawa.
The current status of all these areas within Japan's Exclusive Economic Zone is undisputed — although a sizeable number of lawmakers in Seoul would like to see Tsushima transferred to South Korean sovereignty.
Regarding areas slated for future surveys, JOGMEC was more cagey. All that Hirotaka Miyake — the member of JOGMEC's geophysical research team who prepared the answers to this reporter's questions — revealed was that, "The Sea of Japan, the Pacific Ocean side of the Ryukyu archipelago and more of northern Japan's eastern coastal waters were candidates (for exploration)." The METI report explained that those areas were determined in part on the basis of positive signs gleaned from previous "two-dimensional" seismic surveys.
By 2012, it is planned that Shigen's survey capabilities will improve as its Japanese operators become more familiar with its operations. Annual survey goals will then be increased to 6,000 sq. km. As a result, by 2018 it is hoped that a total of 62,000 sq. km will have been surveyed.
However, the METI plan allows for delays in Shigen's schedule due to several potential causes: typhoons, dealings with local fishing industries and the risk that other vessels will collide with the streamers. So far, the last has proved the most prophetic. In June 2009, a Maritime Self-Defense Force submarine, Oyashio, collided with Shigen's giant streamers, severing seven of them. A total of 7.25 km of cable was lost at sea.
"For nine days from June 17, when the accident occurred, till June 26, surveying was canceled, meaning we were unable to complete all the surveying that had been planned," Miyake wrote, for JOGMEC, to The Japan Times.
The METI plan suggests that as early as this year, the national government could conduct exploratory drilling based on the data collected by Shigen. But, according to JOGMEC, that goal has been set back. "There are no plans to start boring this year," Miyake wrote.
"Once the seismic survey has been completed, the data needs to be processed, analyzed and a report of findings made," Miyake explained. Consideration of whether and where to bore will only be made after that.
In the event that boring does proceed and successfully locates commercially viable oil reserves, the undersea data will then be made available to the private sector. Oil companies will be free to conduct their own supplementary experimental boring and, if the results are positive, new oil fields could be developed.
"Generally speaking, it takes about 10 years from the exploratory boring stage through to the commencement of extraction," Miyake wrote.
After a century of being famously resource-poor in fossil fuels, Japan may yet strike it rich. But, with any discoveries likely to be in waters at least as deep as the 1,200 meters in which the Deepwater Horizon rig was operating, oil extractors and Japan's regulators will have to reap any newfound bounty with the utmost attention to safety and the environment.