羌塘盆地唢呐湖地区煤系地层烃源岩特征研究

Research on Source Rock Characteristics in Coal Measure Strata of Suonahu Area in Qiangtang Basin

唢呐湖地区位于羌塘盆地中部,二叠系热觉茶卡组为一套滨岸相三角洲前缘、潟湖沉积含煤建造地层。热觉茶卡组总有机碳3.68%,生烃潜率0.68 mg/g,氯仿沥青"A"0.17‰,达到了较好烃源岩丰度标准;具有前低后高的双峰型特征,主峰碳主要为C23,整体为Ⅱ型或Ⅱ2型干酪根类型。通过冻土条件、烃源岩条件储盖条件方面进行了天然气水合物地质条件总结,认为区泥火山地区以东,构造圈闭较好,新构造运动不发育,是有利区块内最有利于天然气水合物成藏的区域。

Suonahu area is in the middle of develops shore face with delta front and lagoon Qiangtang basin, Rejuechaka formation of Permian deposits, which are coal-bearing series. Total organic carbon content in Rejuechaka formation is 3.68% ,potentials of generation hydrocarbon of kerogens is 0.68 mg/g and bitumen ＂A＂ is 0.17%o, all of which are fair to good source rock;Double peak is front- low-rear-high with the main peak carbons to be C23. The kerogen types of whole source rock are dominated to Ⅱ type or Ⅱ 2 type. Through geology conditions evaluation of gas hydrate comprise of frozon soil conditions, hydrocarbon source rock conditions and reservoir and cap conditions evaluation, shows that east area of mud volcano area is the most favorable for reservoir of gas hydrate with good structural trap and tectonic movement is agenesis.