天然气水合物泥浆制冷传热效率优化实验的设计与实践

Design and Practice of Experimental Teaching Exploration Based on Mud Refrigeration for Gas Hydrate

冻土天然气水合物在钻探取心过程中极易因为温度升高而发生分解,因此需采用泥浆制冷系统将钻井泥浆的温度控制在0℃以下,抑制水合物的分解。换热器是泥浆制冷系统的核心设备,选择合适的换热器结构是获得低温泥浆的关键。该文通过室内实验研究3种换热器结构的换热效果,以泥浆出口最低温度、进出口温差以及换热功率3个关键参数作为指标,评价3种换热器的换热效果。结果显示螺旋折流板换热器能够获得最低的泥浆出口温度为-2.1℃,进出口温差达到4.1℃,具有良好的换热效果。最后针对换热器关键工艺参数及泥浆制冷系统关键设备的选型提出了指导性意见。

Natural gas hydrates are easily decomposed in the process of drilling cores because of an increase in temperature,so it is necessary to control the temperature of drilling mud in the mud refrigeration system below 0℃to inhibit the decomposition of hydrate.Heat exchanger is the core equipment of the mud refrigeration system,and selecting a suitable heat exchanger structure is the key to obtain low temperature mud.The three key parameters of the minimum mud outlet temperature,temperature difference between the inlet and outlet and heat transfer power were taken as indicators to evaluate the effect of the three heat exchangers.The results showed that the minimum mud outlet temperature of spiral baffle heat exchanger could be-2.1℃,and the inlet and outlet temperature difference reached 4.1℃,which showed a satisfied heat transfer result.Finally,the key process parameters of heat exchanger and the selection of key equipment of mud refrigeration system were proposed.