Substantial progress made in deep coal bed methane exploration in Yan'an

A substantial progress has been made in the exploration of Paleozoic coal seams in Yan'an, Shaanxi province of Northwest China, said developer the Gas Field Company of Yanchang Petroleum on Nov 30.

These seams are anticipated to produce over 30,000 cubic meters of gas per day per well, breaking the record for the highest daily output of this type of resource in Yan'an gas field.

The project developer, the Gas Field Company of Yanchang Petroleum, said such a discovery showed that the exploration and development of deep coal bed methane in Yan'an gas field has great potential.

Coal bed methane refers to natural gas stored in coal seams, commonly known as "gas". Coal bed methane buried deeper than 1,500 meters is commonly referred to as deep coal bed methane.

The company highlighted the increased complexity of formation mechanism and geological conditions for deep coal bed methane compared with medium and shallow reserves. With rising burial depths, formation temperature, pressure, and stress escalate significantly, amplifying the challenges and costs of exploration and development.

The coal seam burial depth of Yan'an gas field exceeds 2,000 meters and is notably thinner compared with the surrounding discovered coal seam gas fields. This geological makeup intensifies the intricacy of exploration and development endeavors, said the company.

Extracting natural gas at such depths also presents challenges such as a lack of technical experience, complex engineering processes, and difficulty in profitability, the company noted.

To address these bottlenecks, the Gas Field Company of Yanchang Petroleum said it actively pursued a coal bed methane exploration and development strategy tailored to the Yan'an Gas Field. By prioritizing key core technologies — geology, drilling, fracturing, and drainage — the company engaged in industry research, expert consultation, and rigorous quality control measures throughout the entire process.