摘要
勘探实践证实,鄂尔多斯盆地延长组主要的烃源岩长7泥页岩具备形成页岩气的基本地质条件,其分布范围广,厚度稳定(80~130m),埋深较浅(500~2000m),热演化程度较高(1.25%~1.40%),干酪根类型以偏腐泥型(Ⅱ_1)为主,有一定的资源潜力,但目前对其生烃过程及机理认识不清。通过热模拟实验及数值模拟方法再现烃源岩生烃历史过程,得到不同温度条件下烃源岩油气生成量,结果表明,页岩中存在油气的共生关系,根据成烃过程可划分为4个阶段,研究区有机质转化率值小于90%,达到成熟的湿气窗阶段,气油比小于2500m^3/t,其中陆相页岩气为偏腐泥型的干酪根在早白垩世早期至晚白垩世(100~130Ma)时达到低成熟—成熟阶段裂解形成,综合分析认为研究区具备形成页岩气藏的烃源岩条件。
The Mesozoic Chang7 Lacustrine shale in in south of Ordos Basin has possesses the basic geological conditions to accumulation of shale gas, Chang7 shale deposit under the background of Lacustrine facies sedimentary, the thickness of the stable（80-130m）, shallow depth （500 to 2000m）, thermal evolution degree of medium-high （1.25% to 1.40%）, kerogen of Chang 7 lacustrine shale has the characteristics of hybrid type, with type Ⅱ1 （sapropelic） in dominance. Chang 7 lacustrine shale Has certain resource potential, but the hydrocarbon generation process and mechanism is not clear. We got different the amount of hydrocarbon source rock hydrocarbon generation under different temperature conditions with the help of reproduction of hydrocarbon source rocks historical process through thermal simulation and numerical simulation methods give different temperature. The result shows that the symbiotic relationship of oil and gas existed in the shale can be divided into four stages according to the maturity evolution process.The ratio of organic matter conversion Less than 90% ,to window of the moisture generation in the mature stage, gas-oil ratio is less than 2500m^3 /t. The lacustrine shale gas be generated by partial sapropelic type organic matter cracked initially in Immature-mature stage of the early cretaceous to early late cretaceous （100 to 130Ma） .Comprehensive analysis shows that the study area has the hydrocarbon source rock condition of shale gas reservoir.
出处
《非常规油气》
2014年第1期2-10,共9页
Unconventional Oil & Gas
基金
国家科技重大专项子课题"鄂尔多斯盆地东南部页岩气成藏规律与有利勘探区评价"(2011ZX05008-004-70)
关键词
页岩气
陆相泥页岩
热模拟实验
油气共生
生烃量
shale gas, lacustrine shale,the thermal simulation experiment, the symbiotic relationship of oil and gas, hydrocarbon generation quantity
