利用石油包裹体烃组分信息恢复塔中地区油气成藏过程  

Applying Molecular Compositions of Inclusion Data to Restore Hydrocarbon Charge History in the Tazhong Area

作　　者：姜振学[1,2] 李峰[1,2] 李卓[1,2] 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)非常规天然气研究院,北京102249

出　　处：《现代地质》2013年第5期1193-1201,共9页Geoscience

基　　金：国家自然科学基金项目(40972088);国家"973"项目(2011CB201105);国家油气重大专项项目(2011ZX05003-001)

摘　　要：为恢复塔中地区油气成藏过程,利用改进的石油包裹体烃组分分析方法进行了详细的研究。结果表明塔中地区储层油和包裹体油的组分差异明显。包裹体油和下奥陶统储层油中伽马蜡烷和C28甾烷相对丰度较高,来源于寒武系—下奥陶统烃源岩,其他储层油中伽马蜡烷和C28甾烷相对丰度较低,来源于中—上奥陶统烃源岩。储层油的成熟度高于对应层位的包裹体油,表明高成熟度的石油再次充注。石炭系和志留系包裹体油和储层油中存在25-降藿烷系列,表明石油成藏后遭受了生物降解作用。恢复了塔中地区3期油气成藏过程,第1期和第2期分别为志留纪末期和二叠纪末期来源于寒武系—下奥陶统烃源岩的油气成藏,第3期为二叠纪末期来源于中—上奥陶统烃源岩的油气成藏。In order to restore the hydrocarbon charge history in the Tazhong area,an improved molecular com-position of inclusion （MCI）method is applied using oils from oil-bearing inclusions （FI-oils）and crude oils. The results show that the FI-oils and the crude oils in the Tazhong oil field originated from different source rock intervals and the crude oils are more mature than the FI-oils.The FI-oils adsorbed and inclusion oils of the reservoir rocks generally have high concentrations of gammacerane and C28 steranes,similar to the Cambrian-Lower Ordovician source rocks.In contrast,the crude oils generally have low concentrations of gammacerane and C28 steranes,similar to the Middle-Upper Ordovician source rocks.The coexistence of 25-norhopane and the intact n-alkanes in all crude oils,and the higher concentration of 25-norhopanes in crude oils than in FI-oils,suggest that later non-biodegraded oil continue to charge and mix in the productive intervals during and/or after early biodegradation.Three episodes of oil charge from two source rock intervals can be restored in the Tazhong area.The first and the second episodes of oil charge,origin of the Cambrian-Lower Ordovician source rocks,were determined in Late Silurian and Late Permian,followed by the third episode of oil charge derived from the Middle-Upper Ordovician source rocks in the Late Permian.

关 键 词：塔中地区 包裹体烃组分 油气来源 生物降解作用 油气成藏过程 

分 类 号：TE122[石油与天然气工程—油气勘探]