Feasibility Study of Applying Steamflooding in a Reservoir with High Shale/Sand: Teca Field
哥伦比亚拥有丰富的重油资源，主要分布于东洛拉诺（Llanos Orientales）和玛格达莱纳中游盆地（Magdalena Valley Medium Basin）。Teca 油田位于该盆地，其开发主要依赖蒸汽吞吐（Cyclic Steam Stimulation, CSS）方法，采收率仅约 15%，表明仍有大量剩余油未被动用。由于该油田具有高页岩/砂岩互层特征，页岩层可能作为“贼层”影响蒸汽驱的热效率，因此是否适合实施连续蒸汽驱（Steamflooding）尚不明确。
本文通过数值模拟与解析模型相结合的方法，研究了页岩夹层对蒸汽驱热效率的影响，并评估了不同操作参数（如注入速率、蒸汽干度、选择性注入方案）对开发效果的影响。
🧪 CMG 软件应用情况
本研究使用 CMG 的 STARS 数值模拟器进行热采模拟，具体应用包括：
| 应用方向 | 具体内容 |
| 模型构建 | 建立具有页岩夹层的非均质油藏模型，模拟 A、B 两层砂体，考虑页岩作为贼层的热力学影响 |
| 历史拟合 | 模拟蒸汽吞吐过程（CSS），包括 14 轮注汽历史，拟合实际生产数据 |
| 敏感性分析 | 分析注入速率（600 bbl/day 最优）、蒸汽干度（60% 最佳）等参数对采收率的影响 |
| 方案对比 | 比较均质模型与实际模型的热效率差异，评估页岩贼层的影响（热效率降低约 30%） |
| 优化设计 | 评估选择性注入方案对蒸汽驱效果的提升作用，显著改善下部砂体（Sand B）的动用程度 |
✅ 结论
- 页岩贼层显著降低蒸汽驱热效率，最多可减少约 30%，严重影响项目经济性。
- 选择性注入策略能有效改善蒸汽驱效果，是解决层间非均质性问题的关键手段。
- 在 Teca 油田实施蒸汽驱技术上可行，但需优化注入策略和井网设计。
- CMG STARS 是研究热采过程、评估复杂油藏蒸汽驱可行性的有效工具，能够处理页岩贼层对热效率的影响。
👨🔬 作者单位
- 哥伦比亚国家石油公司（Ecopetrol）
Abstract
Colombia is a country with important reserves of heavy oil, located mainly at the “llanos orientales” and at the “Magdalena Valley Medium” basin, the oilfields located in this basin, have been developed using cyclic steam stimulation, showing recovery factors close to 15%, indicating that a large quantity of oil has not been removed yet.
Due to the above reasons, it has been thought in the steam flooding as an alternative for the extraction of remaining oil, but the intercalated shale in the deposits in question, acting as thieves, heat affects the thermal efficiency of the process, why is not clear whether the steam flooding will be viable in the deposits of the Magdalena valley, specifically in the TECA field. Given the above, it is necessary to conduct a study to determine the effect of the intercalated shale on thermal efficiency. This study was carried out using numerical simulation and analytical models in the case of a numerical simulation model was compared with intercalations of shale and a homogeneous model, we conducted a further analysis of sensitivity to the rock and fluid properties, as well as operational parameters for the implementation of a steam flooding, including a scheme of selective injection.
Finally, we found that the thermal efficiency is greatly affected by the intercalated shale is decreasing by up to 30%, a value considerably higher than would seriously affect the technical and economic feasibility of the project but has been observed to implement a scheme of selective injection could increase the efficiency of the process, making this more feasible to perform.
