Abstract Due to improvements in well development, shale gas production has gained importance in recent years, especially in the United States. To improve gas production and develop a better understanding of shale reservoirs, researchers are conducting field tests to monitor CO2 storage and enhanced gas recovery. Reservoir simulations can then utilize these field results for sensitivity studies, uncertainty analysis, history matching, gas production forecasts, and CO2 storage capacity estimations. One such field test was performed for the Chattanooga Shale formation in Morgan County, Tennessee. Approximately 463 tonnes (510 tons) of CO2 was successfully injected into a hydraulically fractured horizontal well over a thirteen-day period in March 2014. The injection test was achieved in four steps: pre-injection, injection, soaking, and flowback. In this paper, those steps were modeled with a reservoir simulator to match the historic production and injection rates with gas component compositions and forecast the production for five years. The reservoir fluid was modeled as a multi-component gas, including CH4, C2H6, C3H8, N2, and CO2. Langmuir constants, reservoir pressure, and fracture network volume were adjusted to match simulation results with observed production rates and gas composition. Results showed that, under the same reservoir conditions, each gas component behaves differently by way of compositional changes in production. CH4 behaves like N2, while CO2 behaves like heavier hydrocarbons such as C2H6 and C3H8. CO2 plume results showed that, after injection, the produced CO2 is mostly derived from fractured limestone (i.e., Fort Payne Formation) because the injected CO2 is not adsorbed in limestone but rather by shale formations.

中文翻译：

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田纳西州页岩气水平井二氧化碳“吞吐”注入试验的灵敏度和历史匹配分析

摘要 近年来，由于油井开发的改进，页岩气生产变得越来越重要，尤其是在美国。为了提高天然气产量并更好地了解页岩储层，研究人员正在进行现场测试以监测 CO2 储存和提高天然气采收率。然后，储层模拟可以利用这些现场结果进行敏感性研究、不确定性分析、历史匹配、天然气产量预测和 CO2 储存容量估计。对田纳西州摩根县的查塔努加页岩地层进行了一项此类现场测试。2014 年 3 月，在 13 天的时间里，大约 463 吨（510 吨）CO2 成功注入水力压裂水平井。注入测试分为四个步骤：预注入、注入、浸泡和返排。在本文中，这些步骤使用油藏模拟器进行建模，以将历史产量和注入速度与气体成分组成相匹配，并预测五年的产量。储层流体被模拟为多组分气体，包括 CH4、C2H6、C3H8、N2 和 CO2。调整朗缪尔常数、储层压力和裂缝网络体积，以将模拟结果与观察到的生产率和气体成分相匹配。结果表明，在相同的储层条件下，每种气体组分通过生产成分的变化表现出不同的表现。CH4 的行为类似于 N2，而 CO2 的行为类似于较重的碳氢化合物，例如 C2H6 和 C3H8。CO2 羽流结果表明，注入后产生的 CO2 主要来自破碎的石灰岩（即，