摘要
针对碳酸盐岩发育区烃源岩普遍存在二次生烃的问题,以苏北盐城凹陷朱家墩气藏源岩二叠系栖霞组灰岩为目标,应用化学动力学方法定量研究该源岩的二次生烃(气)。在模拟实验基础上,选取动力学模型,求取动力学参数,再结合朱家墩地区的埋藏史和热史,最终求取了源岩生气史曲线。得出在距今240～190Ma(三叠纪—早侏罗世)时二叠系灰岩第一次生气,随后地层抬升,生气过程中止;在距今54Ma(始新世)时该烃源岩埋藏条件达到了第一次生气终止时的条件,开始第二次生气,生气过程一直持续到现今,第一次生气量(10%)远无法与第二次生气量(80%)相比。并通过储层包裹体的均一化温度判断朱家墩气藏流体注入期次,结果显示,二次生气的生气高峰与流体注入期相匹配,验证了用动力学方法评价二次生烃、多次生烃的合理性,同时也佐证了二叠系灰岩对朱家墩气藏的贡献。
Carbonate source rocks usually have secondary hydrocarbon generation. The secondary hydrocarbon generation of Permian Qixia Formation carbonate source rocks of Zhujiadun reservoir in Yancheng sag, Subei basin was quantitatively studied using chemistry kinetics method of hydrocarbon generation. Selecting kinetics model and on the basis of Simulation experiment, we obtained the dynamic parameters. Considered the burial and thermal evolution history of the Zhujiadun area, the curve of gas formation of the source rock was finally derived. Permian carbonate source rock generated gas for the first time in 240 - 190 Ma （T -J1）. Then, the strata rifted and the gas formation stopped. The source rocks reached the condition of the ending of the first gas generation 54 Ma ago （NI）, then, the second gas generation began, and lasts until now. Compared to the second one （80%）, the quantity of the fist generation （ 10% ） is very, small. Homogenization temperatures of the fluid inclusions were used to estimate the injection time of the fluid. The results shows that the time of the climax of the second generation was consistent with that of the injection of the fluid, showing the rationality of using kinetics method to estimate the secondary hydrocarbon generation or multi-times hydrocarbon generation, and also demonstrating the contribution of the carbonate source rocks to the Zhujiadun reservoir.
出处
《地球化学》
CAS
CSCD
北大核心
2008年第3期251-257,共7页
Geochimica
基金
中国石油股份公司攻关项目
中国石油风险基金(2005-01-02)
关键词
碳酸岩
二次生烃
动力学
模拟实验
朱家墩气藏
江苏省
carbonate rock
secondary hydrocarbon generation
kinetics
simulation experiment
Zhujiadun reservoir
Jiangsu Province
