Application of Element Balance Method to Evaluate the Quantity and Period of Biogas Generation

The period of biogenic gas generation plays a very important role in its accumulation, but till now there is no creditable and effective method to appraise it at home and abroad. It is a material balance process of organic elements during organic matter evolution, regardless of the mechanisms of biogenic gas. In this article, the element balance method is explored and established to appraise biogenic gas, which is demarcated and applied according to the abundant analyzed data in Songliao basin. Results indicate that the depth of biogenic gas generation is possibly shallower than 800 m; the biogas-generated quantity of source rock in this area is about 285.0 × 1012 m3. And the main period of biogenic gas generation occurs before the end of Nenjiang period.