Photo: Courtesy of CNOOC

Major Chinese oil company, CNOOC, on Monday announced the discovery of China's first deep coal-bed gas field with proven reserve exceeding 110 billion cubic meters (bcm) in North China's Inner Mongolia Autonomous Region. 

The find is of great significance in supporting China's energy security and supports the development of the western regions of the country, the company said.

Located within the Shenfu Deep Coal Bed Gas Field near the eastern edge of the Ordos Basin, Inner Mongolia, the find is 2,000-meter deep and absorbed within a coal reservoir that is 6.2 meters to 23.3 meters thick. 

CNOOC has currently deployed over 100 exploratory wells, with the maximum daily output of a single well reaches 26,000 cubic meters, the company told the Global Times in a statement.

Coal bed gas stored under 1,500 meters is classified as deep coal bed gas. It is estimated that China's coal bed gas resource totals over 30,000 bcm, buried at 2,000 meters or shallower and about one third of theses deposit sit below 1500 meters.

Due to the complex technology, technical requirements and equipment, extracting deep coal bed gas has long been regarded as an off-limit area for exploration.

The Shenfu field is the second large gas field with proven reserves over 100 bcm discovered by CNOOC in recent years.

After deploying new exploration techniques, such as using ultra-large-scale fracturing technology and continuously optimizing fracturing and drainage processes, and optimized working protocols on deep coal seam development suitable for the Shenfu block, it took CNOOC one and a half years to reach current development levels.

The discovery in the Shenfu gas field offers insights to the vast potential of deep coal bed gas exploration and extraction in the Ordos Basin and provides key reference to exploring other Chinese deposit sitting in basin geography and the ramping up of output of unconventional oil and gas, according to Xu Changgui, CNOOC's deputy chief exploration engineer.

CNOOC CEO Zhou Xinhuai said the gas find creates a solid foundation for CNOOC's plan to develop both offshore and overland gas filed and to build an overland gas exploration zone of over 1,000 bcm, advancing breakthroughs in the production of unconventional gas.

To ensure energy security amid a highly volatile global market, China has been ramping up domestic output and expanding energy storage capacity in recent years.

A dedicated push in ramping up domestic energy sources extraction has led to natural gas output to grow to 220.1 bcm, up from 160.2 million tons five years ago, according the National Energy Administration in July. China's self-sufficiency rate for natural gas has been lifted from 55.7 percent to nearly 60 percent over the past five years.