AKIPRESS.COM - Japan Petroleum Exploration Co. announced Monday that it was the first company to begin commercial production of shale oil in Japan.

The developer of oil and gas reserves known as JAPEX kicked off production on April 1.

This followed the successful extraction of oil from shale formations in October 2012 in Yurihonjo, Akita Prefecture.

Shale oil had been considered an unconventional resource that was difficult to extract, the Japan Times said. 

However, recent technological improvements and rising crude oil prices have combined to make production more profitable.