摘要
塔里木盆地古城墟隆起GL3井在鹰山组发现了大量固体沥青,其主要赋存于泥晶砂屑灰岩及云质灰岩的溶孔和裂缝中.通过岩心观察、显微照片和沥青反射率(Rb)等分析,发现沥青边界较清晰,不溶于有机溶剂氯仿,无荧光显示,Rb为2.76%~2.85%,与焦沥青的基本特征相似,表现为古油藏裂解的残迹.GL3井鹰山组沥青的发现具有两大地质意义:①沥青发育段与围岩波阻抗的差异可能是GL3井鹰山组“串珠状”地震强反射形成的主要原因,会造成对该井储层预测的偏差;②根据包裹体测温,沥青和天然气成因、埋藏史及生烃史分析,恢复GL3井古油藏的成藏过程,其大致可分为加里东中—晚期古油藏形成与喜马拉雅晚期古油藏裂解成气并转变为焦沥青残迹的两大过程.该研究这对深化古城墟隆起成藏过程研究具有一定意义.
Great number of soild bitumen have been found in Yingshan Formation from GL3 well in Guchengxu Uplift of Tarim Basin. It occurred in the vug and fissure of micritic calcarenite and dolomitic limestone. Based on the analyses of core observation, micrograph and coefficient of reflection, we found that bitumen has many characteristics of clear boundary, insoluble in chloroform, no fluorescent display, with coefficient of reflection ranging from 2.76% to 2.85%. This characteristics are similar to pyrobitumen resulted from paleo-reservoir cracking. The discovery of bitumen in Yingshan Formation in GL3 well has two major geological significances: ( 1 ) the difference of wave impedance between bitumen development segment and wall rock may be the main reason for string beads reflection in Yingshan Formation in GL3 well, and can cause a deviation of reservoir prediction of; (2) through the analysis of inclusion thermometry, origin of bitumen and gas, burial history and hydrocarbon generation history, we reconstructed the accumulation process of the paleo-reservoir in GL3 well We can divide the process into two phases: Middle-Late Caledonian paleo- reservoir formation and Late Himalayan paleo-reservoir cracking to gas and transforming to pyrobitumen. It is of certain significance to deepening the study of reservoir forming conditions of Guchengxu Uplift.
出处
《岩性油气藏》
CSCD
北大核心
2015年第3期82-86,共5页
Lithologic Reservoirs
基金
国家科技重大专项专题"塔里木盆地中央隆起区海相碳酸盐岩层系油气成藏主控因素与勘探突破目标评价"(编号:2011ZX05005-004)资助
关键词
焦沥青
古油藏
“串珠状”反射
成藏过程
鹰山组
塔里木盆地
pyrobitumen
paleo-reservoir
string beads reflection
accumulation process
Yingshan Formation
TarimBasin