贺兰山汝箕沟地区及中卫探区上三叠统烃源岩初步评价  

Preliminary evaluation of the Upper Triassic source rocks in Rujigou area and Zhongwei prospecting area of Helan Mountains

作　　者：张建锋[1] 张金功[1] 吴汉宁[1] 徐春华[2] 董波[2] 

机构地区：[1]西北大学大陆动力学国家重点实验室,地质学系,陕西西安710069 [2]中国石化胜利油田分公司勘探项目管理部,山东东营257000

出　　处：《古地理学报》2008年第5期481-486,共6页Journal of Palaeogeography：Chinese Edition

基　　金：中国石化总公司重大基础研究项目(编号:P06086);中国石化胜利油田分公司勘探项目(编号:2003-kt-02)资助

摘　　要：贺兰山中卫探区是中国石化胜利油田分公司2002年8月份登记的勘探新区。迄今为止,探区内还没有钻井资料,勘探程度非常低。为研究中卫探区上三叠统烃源岩的生烃能力,对探区以北汝箕沟地区上三叠统露头区暗色泥质岩进行了取样分析,结果表明:该泥质岩的有机碳含量为3.03%,总烃含量0.0025%;干酪根显微组分以镜质组为主,类型指数-72.5,属Ⅲ型干酪根;RO值为0.93%,有机质热演化已达到成熟阶段。与探区以东鄂尔多斯盆地延长组烃源岩和石炭系—二叠系煤系地层相比,汝箕沟地区上三叠统泥质岩样品的有机质丰度较高、成熟度好,可作为较好的气源岩。晚三叠世,中卫探区和汝箕沟地区同属滨浅湖相沉积环境,中卫探区更靠近湖盆中心,处于更有利的生烃沉积相带。中卫探区上三叠统烃源岩应具有较好的生气能力,因此,应以该套烃源岩为基础,加强探区内天然气的勘探。The Zhongwei area of the Helan Mountains is a new prospecting area that was registered by the Shengli Oilfield Company of SINOPEC in August, 2002. So far, no drilling has been attempted in the Zhongwei prospecting area and the exploration maturity is quite low. To study the hydrocarbon-generating capability of the Upper Triassic source rocks in the Zhongwei prospecting area, the Upper Triassic dark mudstones in Rujigou area to the north of Zhongwei prospecting area have been collected and analyzed. The results indicate that ： （ 1 ） The content of organic carbon is 3.03%, and the total organic content is 0. 0025%; （2） The kerogen macerals are mainly vitrinite, and the type of organic matter in the mudstones is type Ⅲ kerogen whose type index is - 72.5. （3） The vitrinite reflectance is 0.93%, and the thermal evolution of the organic material has reached the maturity. Compared with the Yanchang Formation and the Carboniferous-Permian coal measures in the east of the prospecting area in the Ordos Basin, the organic matter of the Upper Triassic dark mudstone samples in Rujigou area has a higher abundance and has reached a high maturity, which can become better gas source rocks. The Zhongwei prospecting area and Rujigou area were dominated by the shore-shallow lacustrine facies during the Late Triassic, and the Zhongwei prospecting area was closer to the lake center, and thus the sedimentary facies was more favorable. The Upper Triassic source rocks in the Zhongwei prospecting area have higher gas generating capacity, and the gas exploration in this area should be strengthened on the basis of the source rock evaluation.

关 键 词：贺兰山 汝箕沟地区 中卫探区 上三叠统 烃源岩评价 

分 类 号：TE122.1[石油与天然气工程—油气勘探]