There are signs that shales in Japan could harbour commercially viable oil and gas reserves.
Test drilling by Japex (Japan Petroleum Exploration Co) has demonstrated the presence of oil-bearing shales in the Ayukawa prospect located in the Akita prefecture (district).
Japan is desperately trying to diversify its approach to energy which has for several decades been largely dependent on oil, gas and coal imports, plus nuclear-based power generation. There is severely limited domestic oil and gas production.
However, hopes are high that shales (onshore) and gas hydrates formations (offshore) can be successfully tapped.
The lethal combination of a still weak economy coupled with the Fukushima nuclear disaster have served to drive home to need for alternative domestic solutions to the nation’s mounting energy bill.
Having drilled a well at Ayukawa, Japex succeeded in obtaining oil by pumping hydrochloric acid into the target shale formation located around 1,800m below ground.
Shale oil was confirmed after the produced, acidised fluids were put through a centrifugal separator. The trial lasted four days.
Japex pumped 141,600 litres of fluid into the Ayukawa-1 well and had recovered just over 52,000l of fluids by early on day four of the trial, of which 6,900l was oil.
The company is currently analysing the oil sample obtained and plans to drill a further well next April. A horizontal well is being contemplated. The company is also investigating possible means of extracting the oil other than by acidisation.
The company estimates shale oil deposits at Ayukawa and neighbouring prospects to be around 5million barrels. The Akita prefecture resource base could be as large as 100million barrels oil equivalent, which approximates to 10% of Japan’s annual oil consumption.
Conventional oil reserves were estimated to be around 44million barrels at the beginning of this year.
In 2011, Japan’s total oil production was roughly 130,000 barrels per day of which only 5,000bpd was crude oil. The vast majority of the country’s oil production comes in the form of “refinery gain”, resulting from the country’s large petroleum refining sector.
At the start of the current year, Japan has 148 producing oil wells across around a dozen fields.