基于分布式光纤温度监测的气井产出剖面解释——以中国南海永乐区多层合采探井为例

Interpretation of Gas Well Production Profile Based on Distributed Temperature Sensing Monitoring:A Case Study of Multilayered Exploration Wells in Yongle Area,South China Sea

随着分布式光纤温度(distributed temperature sensing,DTS)监测精度和分辨率的提升,逐渐成为油气生产管理和动态分析中产出剖面监测的重要技术之一,但其解释技术还处于起步探索阶段。考虑流体渗流过程中焦耳汤普逊效应以及诸多微量热效应,结合质量守恒、动量守恒、能量守恒定律建立低渗多层合采气井温度剖面预测模型。该模型耦合了渗流过程中压力和温度场两部分数学模型,求解模型分析讨论了产量、生产时间和渗透率对产出温度剖面影响,结果表明:产量增加产出剖面温度降低;储层渗透率对产出温度剖面影响最为明显;储层渗透率降低,产出剖面温度增加,且增加幅度是非线性的;随着生产时间增加温度增加,但增加幅度逐渐减小且趋于稳定。最后以南海永乐区一口多层合采探井DTS实际温度测试数据进行了产出剖面解释,结果与实际地质认识具有一致性,验证了理论模型的可靠性。该研究结果促进了DTS监测技术在低渗致密多层合采气藏监测中的推广与应用。

With the improvement of the accuracy and resolution of distributed temperature sensing(DTS),it has become one of the important technologies in oil and gas production management and dynamic analysis,but its interpretation technology is still in the initial stage of exploration.The temperature profile prediction model is established about low permeability multilayered commingled production gas well.The Joule Thompson effect and many micro thermal effects in the process of porous flow were considered in the model,combined with the laws of mass conservation,momentum conservation and energy conservation.The model was coupled with two mathematical models of pressure and temperature field in the process of porous flow and the effects of production,production time and permeability for the production temperature profile were analyzed and discussed.The results show as follows.With the increase of production,the temperature of production section decreases.The permeability of reservoir has the most obvious effect on the temperature of production section.With the decrease of reservoir permeability,the temperature of production section increases,and the increase amplitude is nonlinear.With the increase of production time,the temperature increases and the increasing range gradually decreases and tends to be stable.Based on the DTS temperature data of a multilayered exploration well in Yongle area,South China Sea,the production profile is interpreted,and the results are consistent with the actual geological understanding.The reliability of the theoretical model is verified.The results promotes the popularization and application of DTS monitoring technology in the monitoring of low permeability and tight multilayered gas reservoirs.