柴达木盆地三湖地区第四系生物气源岩中可溶有机质丰度及地质意义

Organic Matter Abundance in Quaternary Source Rocks and Its Application on Assessment of Biogenic Gas in Sanhu Lake area,Qaidam Basin

柴达木盆地东部第四系生物气源岩有机质丰度是控制该区生物气资源的关键因素。通过重新设计实验流程,建立了针对未成熟生物气源岩的有机质丰度评价方法。柴达木盆地第四系生物气源岩可溶有机质含量约是不溶有机质含量的2.6倍,有机质大部分以可溶的形式存在。鉴于未成熟生物气源岩有机质赋存形式的特殊性,提出了柴达木盆地东部第四系生物气源岩的有机质丰度评价标准。大量存在的可溶有机质揭示柴达木盆地东部地区第四系仍处于生物甲烷生成阶段,较高的气源岩有机质丰度为生物气勘探提供了重要的资源保障。

Organic matter abundance of quaternary source rock of biogenic gas in eastern Qaidam basin is the key factor controlling biogenic gas resource in the area. By redesigning measurement processes, the assessment method of source rock for biogenic gas is established. The content of dissoluble organic matter in quaternary source rock of biogenic gas is about 2.6 times than that of insoluble organic matter. So most of organic matter in Qaidam basin appear as dissoluble form. Based on the special existing form of immature source rock of biogenic gas, the assessment system of organic matter abundance for quaternary source rock of biogenic gas in Qaidam basin is suggested. Appearance of giant amount of dissoluble organic matter in the quaternary source rocks illustrates that there still is methane generation in the area, and abundant organic matter in source rock provides a resource guarantee for biogenic gas exploration.