In the past two decades

Sinopec Northeast Oil Gas Company has made significant strides in exploring the southern Songliao Basin

revealing that the basin's volcanic rocks present a new and promising avenue for hydrocarbon exploration. According to the exploration practice of the basin

the company has developed a comprehensive four-component coupling reservoir control model specific to fault depressions. This model emphasizes the interconnected evolution of key elements such as hydrocarbon generating foci

reservoir formation periods

paleostructure

fault cap preservation

and effective reservoirs

with a particular focus on the main accumulation period. This strategic approach led to the significant discovery of a large-scale volcanic gas reservoir within the Huoshiling Formation in the Changling fault depression

located in the Songnan area. Consequently

the exploration focus has broadened from the Yingcheng Formation to the Huoshiling Formation

diversifying the exploration targets from acidic volcanic rocks to intermediate-basic volcanic rocks

and extending from subaerial to submarine eruptions. By using the technique of fine gas reservoir description

the integration of modeling

numerical modeling and geological engineering

the productivity breakthrough has been achieved in several wells in Songnan fault depression

and the efficient development and large-scale production of volcanic gas reservoir has been realized.