评价生物气生成量、生成期的元素平衡法及其应用

Application of element balance method to evaluating the quantity and the period of biogas generation

生物气的生成期对其成藏有至关重要的制约作用,但目前国内外尚缺少可信、有效方法来对此进行评价。针对这一难题,考虑到无论生物气的生成机理如何,都是一个有机元素之间的物质平衡过程,文章探索并建立了评价生物气生成量的元素平衡法,并利用松辽盆地大量的实际分析数据,对这一评价方法(模型)进行了标定和应用。结果表明,松辽盆地生物气的生成可能主要发生在800m以浅的埋深条件下;区内源岩生物气的生成量约为285.0×1012m3;生物气的主要生成期在嫩江组沉积末期之前。

The period of biogas generation plays a very important role in its accumulation. Now there is not a credible and effective method to appraise it. The generation of biogas is a mass balance process proceeding among organic elements regardless of the generation mechanism of biogas. We have explored and established an element balance method to appraise biogas in this paper. Using the abundant analyzed data, we applied this method to the study of biogas in the Songliao Basin. Results show that the biogas was generated probably at the depth shallower than 800 meters. The biogas quantity generated from the source rock in this area is about 285.0×10^12 cubic meters. The main period of biogas generation occurs before the end of the deposition of the Nenjiang formation.