China Petroleum & Chemical Corporation ("Sinopec") announced that its Yuanshen-1 risk exploration well in the Sichuan Basin had successfully completed the drilling at a depth of 8,866 meters, beating the previous deepest record in the Sichuan Basin set by its Rentan-1 well.
A major breakthrough of Sinopec's "Project Deep Earth," the Yuanshen-1 well has reached the deepest oil and gas formation in burial depth in the Sichuan Basin and further shows the great potential of deep ancient carbonate rocks in the region.
On the same day, Sinopec officially unveiled the "Project Deep Earth – Natural Gas Base in Sichuan and Chongqing", in collaboration with Sinopec Exploration Company, Sinopec Southwest Oil & Gas Company, Sinopec Zhongyuan Oilfield Company, Sinopec Jianghan Oilfield Company and Sinopec East China Oil & Gas Company. This is Sinopec's third "Project Deep Earth" base after the Shunbei Oilfield and Jiyang Shale Oil bases.
To date, Sinopec's deep natural gas resources in the Sichuan Basin in areas with mineral rights have reached 15 trillion cubic meters, which holds a heavy weight for China's natural gas reserves and production growth.
The Yuanshen-1 well has reached the deepest hydrocarbon reservoir in the Sichuan basin – the mound-shoal complex of the platform marginal facies in Dengying Formation. During the exploration, the ultra-deep carbonate rock, buried at a depth of over 8,700 meters, still showed positive hydrocarbon evidence in the porous reservoir.
Drilling to a depth of over 8,000 meters can bring many challenges for global industrial players. The large-size upper casing weighs 517 tonnes at ground level, which is a challenge to the rig's lifting and casing capabilities. The ultra-high temperature in the deep earth also has high requirements for the drilling fluid's stability and anti-pollution capability, and coring at such depths is difficult and time-consuming. To combat these challenges, Sinopec has developed five key technologies for ultra-deep drilling to support the oil and gas exploration in deep and ultra-deep carbonate reservoirs.
Sinopec has continually advanced deep hydrocarbon exploration in the Sichuan Basin, mainly including conventional gas in deep marine carbonate rocks and deep shale gas. It has discovered the Puguang, Yuanba and Chuanxi gas fields, and to date, Sinopec's annual conventional gas production capacity from deep marine carbonate reservoirs has exceeded 12 billion cubic meters.