Hydrodynamics in subsurface CO2 storage: Tilted contacts and increased storage security
Hydrodynamics in subsurface CO2 storage: Tilted contacts and increased storage security
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DOI：
10.1016/j.ijggc.2016.10.003
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发表时间：
2016-11-01
影响因子：
3.9
通讯作者：
Haszeldine, R. S.
中科院分区：
文献类型：
--
作者：
Heinemann, N.;Stewart, R. J.;Haszeldine, R. S.
在世界各地的沉积盆地中，都有关于超压和盐水流水平变化的水动力含水层的报告。在水动力含水层中，孔隙水向超压降低的方向流动，而圈闭的烃类保持静止。这种压力不平衡在含水层中的主要影响是倾斜的自由水位（FWL）的方向较低overpress.Although石油系统的水动力学的影响是建立在石油工业和勘探和油田开发提供了重要的信息，CO2存储和水动力流的相互作用几乎没有被调查。超临界CO2的密度与北海已知的流体动力系统中的石油密度相当。因此，一个倾斜的CO2-水FWL是预期的，并在规划CO2储存时必须考虑。水动力溢出点将取代结构溢出点，作为CO2储存能力计算中的一个参数。储存安全性取决于CO2溶解速率等因素。CO2越有效地溶解到盐水中，越多的CO2将永久地储存在地下。数值模拟表明，CO2储存在水动力含水层增强溶解的CO2相比，静态制度。当CO2溶解到盐水中时，盐水密度增加，并且CO2饱和的盐水下沉到储层的底部，并被欠饱和的盐水取代。在流体动力系统中，将更有效地从CO2-盐水界面去除饱和CO2的盐水。因此，CO2与更多的欠饱和盐水接触，并以更快的速度溶解。油藏中存在的流体动力学流动需要高度的理解，但对油藏的研究已经证明，这是一个可以充分表征的不确定性。对于长期的CO2储存操作，流体动力学流动甚至可以是更安全的CO2储存的机会。(C)2016爱思唯尔有限公司版权所有
Hydrodynamic aquifers with horizontal variations in overpressure and brine flow have been reported from sedimentary basins worldwide. In a hydrodynamic aquifer pore-waters flow in the direction of overpressure reduction, whereas trapped hydrocarbons remain static. The main effect of this pressure disequilibrium in the aquifer is a tilt of the free water levels (FWL) in the direction of lower overpressure.Although the impact of hydrodynamics on the petroleum system is established in the oil industry and provides important information for exploration and field development, the interaction of CO2 storage and hydrodynamic flow has hardly been investigated. Supercritical CO2 has a density comparable with oil densities in known hydrodynamic systems in the North Sea. Hence, a tilted CO2-water FWL is expected and has to be taken into account during the planning of CO2 storage. Hydrodynamic spill points will replace structural spill points as a parameter in CO2 storage capacity calculations.Storage security is dependent on CO2 dissolution rates, among other factors. The more effectively CO2 dissolves into brine the more CO2 will be permanently stored in the subsurface. Numerical simulations show that CO2 storage in hydrodynamic aquifers enhances the dissolution of CO2 compared with a static regime. When CO2 dissolves into brine, the brine density increases and the CO2-saturated brine sinks to the bottom of the reservoir and is replaced by under-saturated brine. In a hydrodynamic system the brine saturated with CO2 will be removed more effectively from the CO2-brine interface. Hence, CO2 comes in contact with more under-saturated brine and dissolves at a greater rate.The presence of hydrodynamic flow in a reservoir requires a high degree of understanding but research on oil reservoirs has proven that it is an uncertainty that can be adequately characterized. For long term CO2 storage operations hydrodynamic flow can even be an opportunity for more secure CO2 storage. (C) 2016 Elsevier Ltd. All rights reserved.