The need to reduce the maximum injection pressure has been considered an important subject for storage efficiency and safety. Brine extraction from the storage formation is one of the most reliable methods to manage formation pressure. When brine extraction is performed, it is very important to select the optimum location of the extraction well, where the storage efficiency can be maximized. In this study, the sensitivities of the distance between injection/extraction wells and the length or depth of extraction intervals was investigated with a 20,183 metric ton/year injection/extraction rate for 30 years. The injected CO₂ moves upward by buoyancy and spreads horizontally along with the top of the storage formation. Therefore, CO₂ was re-extracted through extraction wells in the case with fully perforated intervals. Even if the intervals were shorter than 20 m, CO₂ was re-extracted with an extraction distance within 500 m from the injection well. Excluding scenarios with CO₂ re-extraction, the injection pressures at injection wells were reduced by 71.7% and the volumes of CO₂ plume increased by 18.8%, compared with the maximum pressure and the gaseous volume of CO₂ in case 1. It was found that the shorter extraction interval of the well located in the bottom part of the reservoir can significantly improve the injection performance, thus reducing the chance of CO₂ re-extraction. With the viewpoint of long-term injectivity, in general, it was confirmed that as the distance of brine extraction increases, the injectivity decreases. However, we could find a considerable exception in general trends. If the extraction well is located within the lateral extension range of the CO₂ migration, brine extraction can limit the lateral migration of CO₂ and consequently increase the overpressure induced by the injection. Therefore, when determining the optimal location of the extraction well, the expected migration range of CO₂ as well as the distance to the injection well, the depth and length of the extraction interval should be considered.

中文翻译：

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压力积累和CO 2迁移对盐水生产的影响

降低最大喷射压力的需求已被认为是存储效率和安全性的重要课题。从储层中抽出盐水是管理地层压力最可靠的方法之一。进行盐水提取时，选择提取井的最佳位置非常重要，在该位置可以最大程度地提高存储效率。在这项研究中，以20,183公吨/年的注入/提取速率研究了30年的注入/提取井之间的距离和提取间隔的长度或深度的敏感性。注入的CO ₂通过浮力向上移动，并与存储地层的顶部一起水平扩散。因此，CO ₂在完全穿孔的情况下，通过萃取井再次萃取。即使间隔短于20 m，CO ₂也会以距注入井500 m以内的萃取距离重新萃取。排除与CO场景₂再提取，在注入井的注射压力是由71.7％降低和CO的体积₂羽流上升18.8％，其中最大压力和CO的气态体积相比₂在壳体1而发现位于油藏底部的井的较短开采间隔可以显着提高注入性能，从而减少了CO ₂的机会重新提取。通常，从长期注入性的观点来看，可以确认，随着盐水提取距离的增加，注入性降低。但是，我们可以在总体趋势中找到相当大的例外。如果萃取井位于CO ₂运移的侧向延伸范围内，则盐水萃取会限制CO ₂的侧向运移，从而增加注入引起的超压。因此，在确定萃取井的最佳位置，CO ₂的预期迁移范围以及到注入井的距离时，应考虑萃取间隔的深度和长度。