摘要
鲁西地区上古生界煤系烃源岩发育,为落实其煤成气的勘探潜力,通过野外剖面细测和钻井资料分析等手段,确定了该区烃源岩的类型和分布特征为:上古生界烃源岩主要由煤层、碳质泥岩、暗色泥岩组成,绝大部分地区烃源岩的有机质类型为腐殖型;煤层主要分布于石炭系太原组和二叠系山西组,具有层数多、单层厚度薄的特点。根据有机质丰度、干酪根组分等指标,结合构造演化史将各凹陷烃源岩的生烃演化过程划分为3种类型,在此基础上,评价了各凹陷烃源岩的生烃能力。结论认为:①济宁、巨野凹陷烃源岩为印支期一次生烃型,汶上凹陷烃源岩为印支—喜马拉雅山期二次生烃型,这两种类型烃源岩的热演化程度不高,对该区煤成气成藏贡献较小;②黄口、成武、鱼台凹陷烃源岩为印支—燕山期、喜马拉雅山期二次生烃型,烃源岩在古近纪大面积成熟,生烃潜力最大(鲁西地区喜马拉雅山期生成煤成气资源量为970.81×108 m3,其中黄口、成武、鱼台3个凹陷占据总资源量的93.6%),为最有利的勘探目标区。
The Upper Paleozoic coal measure source rocks are well developed in the Luxi area, western Shandong, China. In order to determine the exploration potential of coal-derived gas there, we studied the types and their distribution features of the source rocks through outcrop observation and drilling data analysis. In this area, the Upper Paleozoic source rocks are mainly composed of coal beds, carbonaceous mudstones and dark mudstones, and most source rocks have humic-type organic matters. The coal beds are mainly distributed in the Carboniferous Taiyuan and the Permian Shanxi Formations, and are characterized by a large number of lay- ers and a small thickness of each layer. Three types of hydrocarbon generation processes were recognized in the source rocks in each depression according to the organic abundance, composition of kerogen and in combination with the tectonic evolution history. The hydrocarbon-generation potential of the source rock in each depression was evaluated, from which the following conclusions were drawn. The source rocks in the Jining and Juye depressions belong to the primary hydrocarbon generation type of the Indosinian epoch, while that in the Wenshang sag belong to the secondary hydrocarbon generation type of the Indosinian - Himalayan epoch. Both of them are low in thermal maturity and minor in contribution to coal-derived gas accumulation. The source rocks in Huangkou, Chengwu and Yutai depressions belong to the secondary hydrocarbon generation types of the Indosinian - Yanshanian and Himalayan epochs, and got mature in a large area in the Paleogene Period and have the greatest hydrocarbon generation potential, thus are the most favorable exploration targets. Among the total Ct3M gas-in-place of 970.81 × 10^8 m3 generated in the Himalayan epoch in the Luxi area, the resource reserves in the above three depressions account for 93.6%.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2013年第2期17-21,共5页
Natural Gas Industry
关键词
鲁西地区
晚古生代
烃源岩
生烃演化
生烃潜力
干酪根
煤成气
勘探区
Luxi area, Late Paleozoic, source rock, hydrocarbon generation evolution, hydrocarbon generation potential, kerogen, coal-derived gas, exploration block
