海上油田隔热空心杆热洗管柱

Heat Insulation Hollow Rod Heat-washing String for Offshore Oilfield

渤海JX油田BX井原油含蜡质量分数10. 2%,井口温度27. 0℃,易出现周期性蜡堵。为实现不停产洗井,避免损坏电泵和电缆,结合海上油田整体采油树以及潜油电泵生产管柱的结构特点,设计了隔热空心杆热洗管柱及与其配套的双通道采油树、定位油管挂、空心杆密封器、自力单流阀等关键井下工具,提出了井口混合液温度的简化算法。现场应用结果表明:采用隔热空心杆热洗管柱进行热洗作业,当洗井液温度为90. 0℃且自力单流阀深度为1 000 m时,井口返出温度达到79. 5℃,高于熔蜡点7. 0℃。该热洗管柱满足现场清蜡需求,可以在海上油田推广使用。

The Well BX of Bohai JX Oilfield with a wax content of 10. 2% and a wellhead temperature of 27℃ is prone to periodic wax plugging. To perform well washing while producing and avoid damage to the electric pump cable, considering the design features of offshore Christmas tree and the submersible electric pump production string, the heat insulation hollow rod heat-washing pipe string and its supporting tools like double-channel Christmas tree, positioning tubing hanger, hollow rod seal and self-powered single-flow valve are designed. A simplified algorithm for calculating the temperature of the wellhead mixture fluid is proposed. The field application results showed that, with the heat insulation hollow rod heat-washing string, given the temperature of the well washing fluid of 90. 0 ℃ and the depth of the self-powered single-flow valve of 1 000 m, the wellhead returned fluid temperature reached 79. 5 ℃, which is 7.0℃ higher than the wax melting point to meet the needs of on-site wax removal. Thus, the developed string can be promoted in offshore oil fields.