本文通过耦合井筒-油藏数值模拟方法，系统研究了孔板式流量控制装置（FCD）的关键特性（孔口尺寸、孔口数量及安装位置）对SAGD（蒸汽辅助重力泄油）开发效果的影响。研究涵盖了注入井（蒸汽分流器）和生产井（流入控制装置）两类FCD的优化配置。
研究表明，注入FCD可实现多点蒸汽注入，优化蒸汽腔分布，显著降低井筒压降（达一个数量级），并延迟蒸汽突破1.5年以上；生产FCD则能通过均衡水平段压力分布，抑制蒸汽窜进。通过建立基于净现值（NPV）最大化的自动优化工作流程，确定了最佳FCD数量、位置及孔口参数组合。

CMG软件应用情况

软件模块 具体应用场景 技术细节
STARS SAGD热采过程数值模拟 模拟蒸汽腔发育、多相流动及传热过程
FlexWell 井筒建模与耦合计算 建立水平井筒模型，模拟井筒内多相管流、压降及热损失，实现井筒-油藏双向耦合（IPSM通信协议）
CMOST FCD参数自动优化 采用DECE（Designed Exploration and Controlled Evolution）优化算法，自动搜索最佳FCD位置、数量及孔口参数，基于NPV目标函数进行多方案优选
关键建模技术：
  • 采用拉丁超立方实验设计（Latin Hypercube）进行敏感性分析
  • 使用响应面法（RSM）分析FCD参数与目标函数（产量、SOR、NPV）的关系
  • 实现显式耦合：STARS计算IPR（流入动态）传递至FlexWell，FlexWell计算操作点回传至STARS

主要结论

  1. FCD经济效益显著：通过优化注入井和生产井的FCD配置，6年运营期内NPV从3100万美元提升至7600万美元，增幅超过145%；其中注入FCD贡献约130%的增值，生产FCD额外贡献约8-15%。
  2. 注入FCD主导开发效果：相比生产FCD，注入FCD（蒸汽分流器）对累积产量、SOR和蒸汽突破时间的改善更为显著；最优方案为在注入井安装2个FCD（分别位于跟端70m和370m处）。
  3. 生产FCD优化压力分布：生产FCD虽对累积产量影响相对较小，但可显著均衡水平段压力分布（压降从300kPa降至120kPa），有效延迟蒸汽突破时间（从4年延长至6年以上）。
  4. 参数敏感性排序：对于注入FCD，孔口直径对产量影响最大；对于生产FCD，孔口数量是控制井底流压的关键参数；流量系数（Discharge Coefficient）敏感性相对较低。
  5. 建立标准化优化流程：提出了基于耦合模拟-自动优化的FCD设计工作流程（地质建模→动态模拟→井筒-油藏耦合→CMOST自动优化），可用于指导实际SAGD井的FCD配置设计。

中文单位：

  • 威德福（Weatherford）公司
In order to optimize production of a SAGD process many strategies have been adopted. These strategies may include; a Dual-Tubing completion which contains short and long tubing strings to inject steam in to the reservoir, Proportional-Integral-Derivative (PID) to control steam injection, flow control devices (FCDs), and others. In all these methods; operators try to maximize ultimate recovery by increasing thermal communication between well pairs, enhancing steam conformance, and improving oil displacement efficiency. Currently flow control devices (FCDs) are widely used in thermal operations. This tool can be installed on both production and injection wells in a SAGD well pair. The FCD tool in an injection well is also known as a steam splitter, which gives the operator the opportunity to target sections of the wellbore to receive steam. In a production well, FCDs are used to develop a uniform inflow along the horizontal section of the wellbore. This helps in managing the interface between the injection and production wells to maximize the productivity. The effects of orifice type FCD properties on a SAGD process have not yet been investigated. These properties include port (orifice) size and port quantities. Locations of FCDs in both injector and producer are another important parameter that needs to be addressed and optimized in a SAGD operation. This paper investigates the impact of each of these FCDs properties along with the location of FCDs on a SAGD process through coupled wellbore-reservoir modeling. In addition; a detailed study is carried out to present a workflow for the FCD optimization that can help engineers to design FCDs in both injector and producer in a SAGD well pair.

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