YANG Yunfeng1,2,3, LI Xianqing1,3*, FENG Songbao1,2, WANG Kangdong1,2, KONG Longxi1,2, DONG Peng1,2, XU Feng1,2, PENG Dehua4, and CHEN Yan4;
(1. State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083, China; 2. College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing 100083, China; 3. State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing 102249, China; 4. Research Institute of Exploration and Development, Qinghai Oilfield Company, PetroChina, Dunhuang 736202, China)
Abstract Based on the results of fluid inclusion study (microscopic characteristics, homogenization temperatures and grains with oil inclusions), the pool-forming time of the Nanbaxian and Mabei 1 oilfields in northern Qaidam Basin was discussed in this paper. Fluid inclusions in northern Qaidam Basin are relatively abundant, including aqueous inclusions and hydrocarbon inclusions. These inclusions are small (5–10 μm), and mainly distributed in quartz fissures, overgrowths and cementations. The abundances of grains with oil inclusions (GOI) are commonly low. The GOI values of most samples are between 2.0%–10.5%, and those of about 40 percent of total samples exceed 5%. The homogenization temperatures of fluid inclusions in different samples are markedly dissimilar, indicating that these inclusions were formed in different periods. According to the measured homogenization temperatures of fluid inclusions and in combination with burial history and thermal evolution history, the Nanbaxian and Mabei 1 oilfields are deduced, which have experienced two hydrocarbon charging periods, with the former of N1-N21 and N22- N23, and the latter of N1 and N1 end – N2, respectively.
Key words oil and gas reservoir; fluid inclusion; homogenization temperature; grain with oil inclusions (GOI); hydrocarbon charging period; petroleum accumulation
* Corresponding author, E-mail: Lixq@cumtb.edu.cn
CHINESE JOURNAL OF GEOCHEMISTRY Vol. 29, No. 4, 2010, page 422-430
© Science Press and Institute of Geochemistry, CAS and Springer-Verlag Berlin Heidelberg 2010
