China Petroleum & Chemical Corporation (Sinopec) has announced a major shale gas exploration breakthrough of its Project Deep Earth - Sichuan and Chongqing Natural Gas Base. The vertical depth of the well reaches over 5,300 m with a 1,312-m-long horizontal section, setting a new record for vertical depth of shale gas wells in China.
The breakthrough will boost the gas reserves and production efficiency in the Puguang area as well as contribute to the development of ultra-deep shale gas in the Sichuan Basin, Sinopec stated. The Puguang gas and oil field is the first extra-large deep and high-sulfur gas field in China with large-scale development and has been efficiently developed for 20 years.
To achieve the goal of long-term stable shale gas production, Sinopec is constantly looking for new resources and eyed the Puguang Upper Permian, but most of the resources are distributed in the ultra-deep field with a burial depth of over 4,500 m, which is regarded as a "forbidden zone" because of the rapid changes in the velocity of the strata. Sinopec tackled the bottleneck through extensive research and technological innovations to realize a 100 percent drilling encounter rate of high-quality shale in horizontal section with drilling precision comparable to "threading a needle in the deep underground" to eventually drill the Tiebei 1HF well successfully.
Sinopec's self-developed 175 MPa ultrahigh-pressure (UHP) fracturing equipment dynamically optimizes the parameters on-site with different strategies for each section and opened up a "man-made gas road" in the high-pressure stratum at the depth of 5,300 meters, bringing back all the resources from the deepest and farthest ends of the gas reservoir to maximize the development.
At present, Sinopec Zhongyuan Oilfield is preparing an overall exploration and development plan for the Upper Permian shale gas in Puguang to promote the efficient transformation of resources.
The exploration and development of shale gas are of strategic importance to China's energy landscape, and Sinopec actively takes the responsibility and discovered the Fuling shale gas field in 2012, which kicked off commercial development of shale gas in China, and Sinopec continues to promote high-quality development of China's shale gas industry.
