摘要
鄂尔多斯盆地中部气田奥陶系碳酸盐岩储层中既有煤型气又有腐泥型气。煤型气的来源为上古生界煤系源岩已无争议,但对腐泥型气的来源则存在着源自石炭系和奥陶系自生自储两种不同观点。研究了奥陶系碳酸盐岩中的有机显微组成特征,从有机岩石学角度将其细分为三个显微组分组、六种显微组分,其中的碳沥青组对于碳酸盐岩生烃潜力的评价及认识天然气来源具有指示意义。奥陶系岩石中沥青的成因与赋存状况的分析表明,奥陶系储层中的碳沥青主要为液态烃热演化的产物,奥陶系碳酸盐岩具有生烃潜力。同位素特征分析亦表明上、下古生界储层中天然气的同位素组成存在较大差异。认为腐泥型天然气来自奥陶系碳酸盐岩本身。
There are not only the humid gases but also sapropelic ga- ses in Ordovician Carbonate reservoirs of the gas fields in cen- tral Ordos Basin.There are no disputed opinions that the humid gases are sourced from carboniferous coal-bearing source rock,but there are two different viewpoints on the sapropelic gases:one suggestion is that they are sourced from carbonif- erous coal-bearing source rock but the contrary suggestion is sourced from Ordovician source-and-reservoir rock.The opin- ion on origin of gases is associated with estimating of Ordovi- cian carbonate rock.Founded on the study of the features of organic maceral in Ordovician carbonate rock,three maceral groups are divided and six kinds of maceral are subdivided.It is believed that the bituminite group has an index significance to evaluate the hydrocarbon potential of carbonate rock and recognize the source of natural gas.In addition,the reason and the modality of bituminite in rock as well as the features on isotope of natural gases in Ordovician and Carbonic—Permian reservoirs have also been researched.It is suggested that the bituminite in rock is the product evolved from hydrocarbon.The Ordovician carbonate rock with hydrocarbon potential can be provided.The sapropelic gases are mainly sourced from the Ordovician carbonate rock.
出处
《海相油气地质》
2003年第1期35-39,共5页
Marine Origin Petroleum Geology
基金
"九五"国家科技攻关项目99-110-01-03中的部分研究成果
关键词
鄂尔多斯盆地
奥陶系
烃源岩
天然气成因
Ordovician
Carbonate rock
Source rock
Origin of gas
Maceral
Bituminite
Natural gas
Ordos basin
