在页岩气吸附过程中甲碳同位素分离的末端混合模型及其应用
Changbo Zhai1,2,3, Cheng Tao1,2,3, Yu Zou3
1State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development, Beijing 102206, China.
ACS omega
|September 9, 2024
概括
一个新的模型解释了在页岩气脱氧过程中甲碳同位素的变化,揭示了吸附和自由气体混合驱动的变化. 在长期的页岩气生产中,吸附气体的贡献仍然很小.
科学领域:
- 地质化学 地质化学
- 石油地质学 石油地质学
- 同位素地球化学 同位素地球化学
背景情况:
- 页岩气开发表现出独特的甲碳同位素转移,目前的模型无法解释.
- 现有的同位素分离模型无法捕捉页岩气系统的复杂性.
研究的目的:
- 建立一个新型的同位素分成模型,在页岩气脱吸过程中用于甲.
- 阐明了在页岩气中控制甲碳同位素分离的机制.
- 量化吸附气体对整体页岩气生产的贡献.
主要方法:
- 在吸附和自由气相中开发了甲的同位素分离方程.
- 构建了考虑吸附和自由气体作为末端成员的同位素混合模型.
- 将该模型应用于现场脱氧气体含量和同位素数据,以进行参数拟合和计算.
主要成果:
- 该模型准确地描述了页岩核脱氧过程中的甲碳同位素变化,显示了"最初负,然后转向正"的模式.
- 吸附和自由气体的混合,以及同位素分离,是影响甲碳同位素组成的关键因素.
- 在JY1井的吸附气体贡献在早期是可以忽略不计的,在七年后仅达到15%,每日产量<300万立方英尺.
- 井JY 6-2显示了更好的吸附气体生产,但自由气体仍然是生产能力的主要贡献者.
结论:
- 开发的模型为了解页岩气中的甲碳同位素分离提供了一个强大的框架.
- 吸附气体在研究的贾芝天然气田的长期生产能力中起到有限的作用,自由气体占主导地位.
- 未来的页岩气生产战略可能需要考虑长期吸附气体的有限贡献.
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