黄陵矿区属于煤油气共生矿区,区内多个工作面发生底板气异常涌出.为探明底板异常涌出气体的成因类型,采集煤层底板气样44 个、2 号煤层气样12 个,进行甲烷碳同位素(δ13C1)、乙烷碳同位素(δ13C2)及甲烷氢同位素(δ DCH4 )等地球化学参数测试.测试分析结果表明,煤层底板异常涌出气不是来源于2 号煤层,其甲烷碳同位素(δ13C1)测值为–52.20‰- –42.80‰,乙烷碳同位素(δ13C2)值为–37.20‰- –29.01‰,成因类型属油型气.通过对区域烃源岩分布及地层裂隙系统的分析,认为黄陵矿区底板异常涌出气可能来源于三叠系延长组烃源岩.
Coal and oil-gas exist in Huangling mining area together, abnormal gas emission from coal seam floor has occurred in multiple working faces. In order to ascertain the genetic type of abnormal gas emission, 44 gas samples were collected from seam floor and 12 samples from NO.2 coal seam, test of geochemical parameters for carbon isotope of methane and hydrogen isotope was conducted. Test and analysis result shows that the abnormal gas is not derived from NO.2 coal seam, the value of carbon isotope of methane(δ13C1) is 52.20‰~42.80‰, and the value of carbon isotope of ethane (δ13C2) is 37.20‰~29.01‰, the genetic type of abnormal gas emission from coal seam floor belongs to the oil-type gas. By analyzing the distribution of source rocks and the fracture system, it is suggested that abnormal gas emission comes from the sourcerock of Yanchang Formation.