my country's first large-scale thin coal bed methane development project is fully operational

The Panhe thin coal-bed methane development project is located in the southern Qinshui Basin of Shanxi Province. A total of 212 wells have been built. The maximum daily production of a single well reaches 11,000 cubic meters, and the average daily production exceeds 2,500 cubic meters. Since trial mining at the end of 2020, the cumulative production of thin coalbed methane in the Panhe block has reached 180 million cubic meters, and the proportion of daily production has climbed to 1/2 of the total production of the block, successfully realizing an efficient conversion from reserves to production.

Coalbed methane refers to the unconventional natural gas associated with coal and stored in the coal seam in an adsorbed state, commonly known as "gas". The development and utilization of coalbed methane can not only effectively solve the problem of coal mine gas control and ensure the safety of coal mining, but also provide new clean energy and achieve environmental protection. At present, the commercial large-scale development of coalbed methane in my country is mainly concentrated in the main coal seams of Qinshui Basin and Ordos Basin. After years of development, the gas production of the main coal seams has declined seriously. In order to achieve production capacity replacement, technical personnel have accelerated the development of thin coal seams.

“There are multiple sets of thin coal seams developed in the Panhe block, and the thin coal seam methane reserves are considerable. However, the thickness of a single layer is thin, with an average thickness of only 0.6 meters, which is only one-tenth of the thickness of the current main coal seams. First, it also has the characteristics of multi-layer stacking, uneven distribution of single layers, and large longitudinal spans, so mining is extremely difficult," said the deputy chief engineer of China National Offshore Oil Corporation.

Thin coal seams generally refer to coal seams less than 1.3 meters thick in underground mining. According to statistics, the recoverable reserves of thin coal seams in my country account for 20% of the total recoverable reserves of coal seams, about 350 billion tons. However, compared with the main coal seams, thin coal seams are like "thousand-layer cakes" with large differences in gas content and relatively low resource abundance. Poor, it has long been regarded as a “marginal resource” in coalbed methane development.

In recent years, due to the dual impact of coal resources and high-level development, in order to achieve production capacity replacement, CNOOC has continued to increase its potential and conducted concentrated research on thin coal seams, forming a thin coal seam. A series of technological innovations such as coal seam identification, complex well network deployment optimization, long-span multi-level fracturing, dual pressure and dual control drainage and production, etc., have built a three-dimensional exploration and development technology system for thin coal bed methane, and realized the resource improvement of thin coal bed methane for the first time in China. storage to achieve efficient utilization of “marginal resources”.

The relevant person in charge of CNOOC China United Company said that the successful commissioning of the thin coalbed methane development project in the Panhe block has provided new ideas and created a new model for the economic and efficient development of domestic thin coalbed methane. In the future, China United will continue to strengthen scientific and technological innovation and vigorously explore new technologies for efficient development of coal bed methane, making new and greater contributions to the construction of CNOOC's onshore trillion-dollar atmospheric area and clean energy base and ensuring national energy security.