泥浆地面降温调控特深钻探井筒泥浆温度的分析研究

Analysis of surface drilling fluid cooling for wellbore temperature regulation in extra-deep drilling

摘要:

针对超万米特深钻探面临的超高温导致井下工具失效及泥浆性能恶化等关键挑战，为明确泥浆地面降温技术的调控效果，本文建立了井筒-地层耦合传热数值模型，并结合牙哈501井实测数据对模型进行了验证。研究中以井底泥浆循环温度、井筒泥浆最高温度和出井泥浆温度为关键评价指标，模拟分析了8000、11000、13000 m三种钻进深度时泥浆地面降温对井筒温度的调控规律。结果表明：三种井深条件下，使用泥浆降温后井底泥浆循环温度、井筒泥浆最高温度分别降低了24.3、24.4 ℃，17.4、17.9 ℃，12.0、12.5 ℃。不使用泥浆降温时，三种井深条件下出井泥浆温度持续升高，4次循环后分别可达92.3、96.2、94.3 ℃，使用泥浆降温后则均稳定在60 ℃左右。本研究为特深钻探井筒温度控制与安全施工提供了理论依据和量化指导。

Abstract:

To address the critical challenges in extra-deep drilling beyond 10000 meters， such as downhole tool failures and drilling fluid performance degradation caused by extreme high temperatures， this study investigates the efficacy of surface cooling of drilling fluid. A numerical model of wellbore-formation coupled heat transfer was established and validated against measured data from Well Yaha 501. Using the bottom-hole circulating temperature， maximum drilling fluid temperature， and return drilling fluid temperature as key evaluation metrics， simulation analysis was conducted to examine the temperature control performance of surface cooling at designed depths of 8000 m， 11000 m， and 13000 m. The results demonstrate that implementing surface cooling reduced the bottom-hole circulating temperature and maximum drilling fluid temperature by 24.3 ℃ & 24.4 ℃， 17.4 ℃ & 17.9 ℃， and 12.0 ℃ & 12.5 ℃， respectively. Without cooling， the return drilling fluid temperature after four circulation cycles reached 92.3 ℃， 96.2 ℃， and 94.3 ℃. In contrast， with surface cooling， it stabilized at approximately 60 ℃. This study provides a theoretical basis and quantitative guidance for wellbore temperature control and safe operations in extra-deep drilling.