川中隆起安岳气田古油藏成藏时间厘定  

Timing of hydrocarbon accumulation for paleo-oil reservoirs in Anyue gas field in Chuanzhong Uplift

作　　者：杨程宇[1] 文龙[2] 王铁冠[1] 罗冰[2] 李美俊[1,3] 田兴旺 倪智勇 Yang Chengyu;Wen Long;Wang Tieguan;Luo Bing;Li Meijun;Tian Xingwang;Ni Zhiyong(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;Exploration and Development Research Institute of Southwest Oil&Gas Field Branch Company Ltd.,PetroChina,Chengdu,Sichuan 610041,China;Key Laboratory of Oil and Gas Resources and Exploration Technology(Yangtze University),Ministry of Education,Wuhang,Hubei 430100,China)

机构地区：[1]油气资源与探测国家重点实验室中国石油大学(北京),北京102249 [2]中国石油西南油气田分公司勘探开发研究院,四川成都610041 [3]长江大学资源与环境学院油气资源与勘探技术教育部重点实验室,湖北武汉430100

出　　处：《石油与天然气地质》2020年第3期492-502,共11页Oil & Gas Geology

基　　金：国家自然科学基金青年科学基金项目(41903059)。

摘　　要：安岳气田是中国目前最大的古老和深层气田,由新元古代-早古生代地层中的古油藏经原位裂解形成。由于古油藏-裂解气藏演化程度较高、时代较老,对其成藏演化的研究,特别是古油藏成藏时间的厘定,长期以来存在较多争议,缺乏足够地球化学证据的佐证。通过最新的实测大地热流史和类似地区的烃源层生烃门限研究,利用地质类比法替代流体包裹体测温,重建关键井埋藏史-热史,厘定德阳-资阳裂陷筇竹寺组烃源层的生烃和古油藏形成和破坏的时间,分析了古油藏的演化过程。地球化学实验和相关地质分析表明,筇竹寺组烃源层生烃时间既古油藏成藏时间约为275~263 Ma,相当于早二叠世后期(孔古阶)-晚二叠世。之后的深埋使古油藏自三叠纪初期开始裂解,在中侏罗世末期-早白垩世初期古油藏被完全破坏并形成大型裂解气藏。Anyue gas field,resulted from the in-situ pyrolysis of paleo-oil reservoirs in the Neoproterozoic-Lower Paleozoic sequences,is one of the largest old and deep gas pools in China.Since the paleo oil-pyrolysis gas pools are high in degree of evolution and very old,and there is in lack of geochemical evidences,the accumulation and evolution,especially the timing of accumulation,remains a controversial issue in study.Starting from the newly-measured terrestrial heat flow history and threshold depth of hydrocarbon generation from source rocks in similar areas,we apply geological analogy method,instead of microthermometry of fluid inclusions,to the analysis of paleo-oil reservoir evolution:reconstructing the burial-geothermal history of key wells,and then determining the timing of hydrocarbon generation in the Qiongzhusi Formation source beds in Deyang-Ziyang rift and of paleo-oil reservoirs’formation and destruction.The results of geochemical experiments and relevant geological analyses indicate that hydrocarbon generation in the Qiongzhusi Formation source rock and paleo-oil reservoir formation occurred around 275263 Ma,corresponding to the late Early Permian-Late Permian.The oil pyrolysis occurred since the early Triassic with deep burial,and the paleo-oil reservoirs were entirely transformed to a pyrolysis gas pools during the late Middle Jurassic-early Early Cretaceous.

关 键 词：埋藏史 成藏时间 裂解气藏 古油藏 安岳气田 川中隆起 四川盆地 

分 类 号：TE122.3[石油与天然气工程—油气勘探]