Coupled Flow and Deformation Modeling of Carbon Dioxide Migration in the Presence of a Caprock Fracture during Injection
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- 作者：Hema J. Siriwardane ; Raj K. Gondle ; Grant S. Bromhal
- 刊名：Energy & Fuels
- 出版年：2013
- 出版时间：August 15, 2013
- 年：2013
- 卷：27
- 期：8
- 页码：4232-4243
- 全文大小：787K
- 年卷期：v.27,no.8(August 15, 2013)
- ISSN：1520-5029
文摘
Understanding the transport of carbon dioxide (CO<sub>2sub>) during long-term CO<sub>2sub> injection into a typical geologic reservoir, such as a saline aquifer, could be complicated because of changes in geochemical, hydrogeological, and hydromechanical behavior. While the caprock layer overlying the target aquifer is intended to provide a tight, impermeable seal in securing injected CO<sub>2sub>, the presence of geologic uncertainties, such as a caprock fracture or fault, may provide a channel for CO<sub>2sub> leakage. There could also be a possibility of the activation of a new or existing dormant fault or fracture, which could act as a leakage pathway. Such a leakage event during CO<sub>2sub> injection may lead to a different pressure and ground response over a period of time. In the present study, multiphase fluid flow simulations in porous media coupled with geomechanics were used to investigate the overburden geologic response and plume behavior during CO<sub>2sub> injection in the presence of a hypothetical permeable fractured zone in a caprock, existing or activated. Both single-phase and multiphase fluid flow simulations were performed. The CO<sub>2sub> migration through an existing fractured zone leads to changes in the fluid pressure in the overburden geologic layers and could have a significant impact on ground deformation behavior. Results of the study show that pressure signatures and displacement patterns are significantly different in the presence of a fractured zone in the caprock layer. The variation in pressure and displacement signatures because of the presence of a fractured zone in the caprock at different locations may be useful in identifying the presence of a fault/fractured zone in the caprock. The pressure signatures can also serve as a mechanism to identify the activation of leakage pathways through the caprock during CO<sub>2sub> injection. Pressure response and ground deformation behavior from sequestration modeling could be useful in the development of smart technologies to monitor safe CO<sub>2sub> storage and understand CO<sub>2sub> transport, with limited field instrumentation.