柴东地区石炭系烃源岩地球化学特征  

Geochemical Characteristics of Carboniferous Hydrocarbon Source Rocks in the Eastern Qaidam Basin

作　　者：段宏亮[1] 钟建华[2] 邱旭明[1] 李亚辉[1] 尹成明 

机构地区：[1]中国石油化工股份有限公司江苏油田分公司,江苏扬州225009 [2]中国石油大学资源与信息学院,山东东营257061 [3]中国石油与天然气股份有限公司青海油田分公司,甘肃敦煌736202

出　　处：《应用基础与工程科学学报》2009年第2期219-230,共12页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(No.40503003);江苏自然科学基金项目(No.BK2008584)资助

摘　　要：柴达木盆地东部祁连山南缘石炭系海相地层发育全、分布广且厚度大,岩性多以暗色泥质岩(包括碳质泥岩)和灰色碳酸盐岩为主.借助于有机元素分析仪、碳硫分析仪、岩石热解仪、色谱-质谱仪、显微镜等分析测试手段,对该区地表30个暗色泥质岩样品有机质丰度、类型、成熟度及生物标志化合物等有机地球化学特征进行了分析.结果表明:石炭系泥质烃源岩氯仿沥青"A"和生烃潜量(S1+S2)含量较低;但有机碳含量较高,介于0.40%—4.93%,平均为1.13%(除两个碳质泥岩样品外).有机质类型以Ⅲ型干酪根为主,部分为Ⅱ2型;烃源岩形成于还原性的较咸水环境,母源以陆生生物为主,也有较丰富的低等水生生物.除北部中务隆山前石灰窑、红山中沟及柏树山地区石炭系烃源岩已变质外,盆地内部都兰地区烃源岩Ro值介于2.44%—2.70%(平均为2.60%),处于过成熟的生干气阶段;石灰沟、城墙沟及扎布萨尕秀等地区烃源岩Ro值介于0.85%—1.39%(平均为1.12%),正处于成熟阶段的生、排烃高峰期.综合评价该区石炭系泥质烃原岩为中等烃源岩,具有一定的生烃潜力,主要以生气为主.Carboniferous formations are well developed on the southern Qilian Mountains in the eastern Qaidam Basin. The thick Carboniferous rocks with wide distribution are mainly dark mudstones （including carbonaceous mudstone ） and carbonate rocks. To evaluate their hydrocarbon potential,30 Carboniferous mudstone-samples on outcrop sections are analysed by means of several organic geochemistry methods. Geochemical characters such as organic matter＇ s abundance, type, maturity and biomarkers are discussed with following The abundance of Chloroform bitumen ＂A＂ and hydrocarbon potential（ S1 ＋ S2 ） is organic carbon is preferable, averaging 1.13%. The organic matters are mainly conclusions ： lower, while of type Ⅲ,with partly type Ⅱ2. The sedimentary organic matters are dominantly derived from higher terrigenous plants with also lower hydrobios input, and deposited in reducing environment of saline water. Except those Carboniferous rocks of Shihuiyao, Hongshanzhonggou and Baishushan area on the Zhongwulong Mountain front, which have metamorphosed, the organic matters of Shihuigou, Chengqianggou and Zhabusagaxiu area reach maturity-high maturity stage, peak period for hydrocarbon generation and expulsion. Dulan area reaches post-maturity stage. Geochemical indexes indicate the Carboniferous muddy source rocks of the eastern Qaidam Basin are preferable source rocks with large gas generation potential.

关 键 词：有机质丰度 有机质类型 有机质成熟度 生物标志化合物 烃源岩 石炭系 柴达木盆地东部 

分 类 号：TE122[石油与天然气工程—油气勘探]