摘要
临兴地区处于开发初期,上古生界煤系烃源岩特征及排烃规律不清,制约了下一步的勘探开发。综合运用测井及分析化验资料,对该区煤系烃源岩的分布、地球化学特征、排烃规律及控藏作用进行了深入研究。结果认为:临兴地区烃源岩为太原组—山西组煤岩、暗色泥岩及炭质泥岩,有机质丰度为中等—好,受沉积环境影响,有机质类型以Ⅲ型为主,含部分Ⅱ_1型和Ⅱ_2型,Ⅱ_1型仅发育于太原组,且从太原组到山西组,Ⅲ型所占比例增大,Ⅱ型所占比例减小;受紫金山碱性杂岩体影响,有机质为高成熟—过成熟,生气强度大于20×10~8m^3/km^2,呈西高东低、北高南低、大面积广覆式生烃特点;排烃强度控制气藏范围,太原组排烃效率及总排烃量优于山西组,对上古生界气藏形成贡献较大。该研究深化了临兴地区上古生界煤系烃源岩的系统认识,为该区煤系致密砂岩气运聚成藏特征及勘探开发提供了重要的参考依据。
The Linxing region is at initial development stage. We are not much clear about the Upper Paleozoic coal -bearing source rock features and hydrocarbon expulsion rule, which has restrained exploration and development of this region. By combining well logging and laboratory test data, we thoroughly studied the distrlbution, geochemical features, hydrocarbon expulsion rule of coal-bearing source rocks and their controlling effect on hydrocarbon accu- mulation in this region. According to the study results： （ 1 ） the source rocks in this region are coal beds, dark mudstone and carbonaceous mudstone in the Taiyuan Formation-Shanxi Formation, with moderate-good organie matter abundance ; （2） being influenced by sedimentary environment, the major organic matter is type m, with fewer type Ⅱ 1 and type Ⅱ2. Type Ⅱ1 organic matter is only developed in the Taiyuan Formation ; （ 3 ） from the Taiyuau Formation to the Shauxi Formation, the ratio of type Ⅲ organic matter increases, and that of type Ⅱ decreases; （4） being affected by the Zijinshan alkali complex rocks, the organic matter is at high-mature and over-mature stages, with gas generation intensity of more than 20× 10 8 mS/km2 ; （5） hydrocarbon generation intensity in this region is characterized by being higher in its west and north and lower in its east and south, and being exten- sive ; （ 6 ） hydrocarbon generation intensity controls gas reservoir scope ; （ 7 ） the hydrocarbon expulsion efficiency and total hydrocarbon expulsion quantity of the Taiyuan Formation are better than that of the Shanxi Formation, thus the Taiyuan Formation contrihutes more to the Upper Paleozoie gas reservoirs. This study has deepened our system- atic cognition on the Upper Paleozoie coal-bearing source rocks in the Linxing region, and provides important referonce for coal -bearing tight sandstone gas migration, accumulation, exploration and development in this region.
出处
《特种油气藏》
CAS
CSCD
北大核心
2018年第1期5-10,共6页
Special Oil & Gas Reservoirs
基金
中央高校基本科研业务费专项基金"鄂尔多斯盆地东缘康宁地区致密砂岩气成藏规律研究"(2652015330)
关键词
煤系烃源岩
烃源岩特征
排烃规律
上古生界
临兴地区
coal-bearing source rock
source rock feature
hydrocarbon expulsion rule
Upper Paleozoic
Linxing region
