Japan Petroleum Exploration Co. (JAPEX) said Wednesday it has succeeded in extracting the country’s first shale oil at the Ayukawa oil and gas field in northeastern Japan. The major developer of natural resources retrieved crude oil from a shale rock layer about 1,800 meters below the Ayukawa field in Akita Prefecture. The company began Japan’s first test production of shale oil on Monday, which is to continue until Thursday. JAPEX estimates around 5 million barrels of shale oil are contained in the Ayukawa and neighboring oil and gas fields. The company also figures it could recover about 100 million barrels of shale oil, equivalent to nearly 10 percent of Japan’s annual crude oil consumption, in entire Akita Prefecture. JAPEX plans to study the amount and speed of extraction to assess its commercial feasibility. The production of shale oil could help increase resource-poor Japan’s energy self-sufficiency. Shale oil is extracted from hard rock layers deep underground by heating and distilling. Shale oil has attracted global attention as a new energy resource, with its production sharply spreading in North America.