塔河油田超临界CO2压裂井筒与裂缝温度场

Supercritical CO2 fracturing wellbore and fracture temperature field in Tahe Oilfield

罗攀登 李涵宇 翟立军 李春月 吕欣润 牟建业4

中国石化西北油田分公司工程技术研究院，新疆 乌鲁木齐 830011 中国石油大学（北京）石油工程学院，北京 102249 中国石油大港油田分公司生产运行处，天津 300280 中国石油大学（北京）克拉玛依校区，新疆 克拉玛依 834000

Petroleum Engineering Research Institute, Northwest Oilfield Company, SINOPEC, Urumqi 830011, China College of Petroleum Engineering, China University of Petroleum, Beijing 102249, China Production Operation Department, Dagang Oilfield Company, PetroChina, Tianjin 300280, China China University of Petroleum?鄄Beijing at Karamay, Karamay 834000, China

采用超临界CO2压裂技术能较好地改造塔河油田水敏、低渗储层，而压裂过程中井筒和裂缝温度场对CO2物性参数影响较大，需要对CO2压裂温度场进行研究。考虑径向非稳态传热、轴向非稳态对流以及摩擦力、黏滞力的影响，推导了井筒温度、压力方程，结合K￣D￣R方法和CO2物性模型，建立了CO2压裂过程中井筒和裂缝温度场计算模型，并通过实测温度、压力数据拟合，验证了模型的准确性。应用所建模型分析了塔河油田胡杨2井CO2压裂施工排量对温度场的影响，结果表明：CO2注入排量对井筒温度、压力以及裂缝温度影响明显，而对裂缝内压力影响较弱；井筒压力梯度随着排量增大而变小；井筒和裂缝中CO2均可存在液态和超临界态2种相态。研究成果能为塔河油田CO2压裂施工设计优化提供一定指导。

The use of supercritical CO2 fracturing technology can better improve the water?鄄sensitive and low?鄄permeability reservoirs in Tahe Oilfield. The wellbore and fracture temperature field in CO2 fracturing process has a great influence on its physical parameters, and the CO2 fracturing temperature field is studied. Considering the effects of radial unsteady heat transfer and axial unsteady convection, as well as friction and viscous forces, the wellbore temperature and pressure equations were derived. Combined with K?鄄D?鄄R method and CO2 physical property model, the calculating model of wellbore and crack temperature field of CO2 fracturing process was established. The accuracy of the model was verified by the measured temperature and pressure data of a well. The influence of CO2 fracturing displacement on the temperature field in Huyang 2 Well of Tahe Oilfield was analyzed. The results show that CO2 injection displacement has obvious influence on wellbore temperature and pressure and crack temperature, but weak influence on crack internal pressure; wellbore pressure gradient becomes smaller as the displacement increases. There are liquid and supercritical states of CO2 in wellbore and fracture. Certainly, this study can provide some guidance for the design optimization of CO2 fracturing in Tahe Oilfield.

10.6056/dkyqt201902019