Depending on the unique core technology, important progress has been made in deep and medium rank CBM exploration in North China Oilfield. Daping 7 well, designed for 1950m to 2045m coal seam in Dacheng block of North China Oilfield, has produced up to 11,000 cubic meters per day since the first 10,000 cubic meters on March 7 and up to March 18.

This is the first time that domestic CBM wells have made breakthroughs in this depth, filling the gap of economic exploitation of deep CBM in the world at 1800 meters.

Coalbed methane resources are abundant in China, which is comparable to conventional natural gas resources. However, due to the strong heterogeneity of coal reservoirs, poor reformability and great influence by burial depth, commercial exploitation of CBM in Qinshui high-rank coal and low-rank coal in eastern edge of Ordos is only realized at present, and the coal seams are all below 800 meters shallow, and the deep area is regarded as the development forbidden zone.

Huabei Oilfield aims at basic theory research and core technology tackling. With the support of major special funds from the state and China Petroleum, it innovatively puts forward the geological theory understanding of “four-element reservoir formation, three-element production control and dredging development” and develops and forms the exploration of “area selection evaluation, reservoir transformation, quantitative drainage, low-cost controllable horizontal well drilling”. Explore and develop key technologies. Relying on new theory and technology, Qinshui breaks through the undeveloped “red line” of 800 meters high rank coal.

In 2014, Huabei Oilfield decided to restart the exploration of Dacheng CBM block located at the junction of Tianjin and Hebei. Scientific researchers and technicians have continuously deployed four vertical wells, two of which have achieved nearly 3,000 cubic meters of high production at 1,750 meters and 2,000 meters, respectively. However, because the wells are too deep, they do not have economic exploitation value. How to realize the benefit development of deep coal-bed methane has become a difficult problem in North China Oilfield.

In 2018, Daping 7 well was designed and implemented scientifically in Huabei Oilfield on the basis of a new theoretical understanding of CBM. With casing pressure of 2.7 MPa and flow pressure of 7.4 MPa, the output per day exceeds 10,000 cubic meters and has great potential for stable production.

The person in charge of Huabei Oilfield believes that the success of well Daping 7 indicates that the exploitable range of CBM in China has increased from 800 meters to about 2000 meters, which is a milestone for the scientific development of CBM in China.