天然气水合物钻井泥浆冷却系统研究及优化

RESEARCH AND OPTIMIZATION OF MUD COOLING SYSTEM IN GAS HYDRATE DRILLING

在天然气水合物钻探中,低温泥浆可以抑制水合物分解,对钻获水合物样品十分重要。吉林大学研制的泥浆冷却系统换热器选择同轴套管式对流换热的冷却方式,载冷剂与泥浆全程逆流。在青海祁连冻土带天然气水合物科学钻探项目中,泥浆冷却系统能够快速冷却泥浆,并将泥浆温度动态维持在低温范围内,达到了设计要求,对钻获天然气水合物样品起到重要的作用。为今后能够为水合物勘探提供更加有力的技术支持,对传热机理与换热器结构进行了进一步研究,设计了三层套管式换热器,换热面积和对流换热系数均大幅度提高,经理论计算与数值模拟,新型换热器换热效率显著提高,满足设计要求所需换热长度明显降低,同时降低了泥浆冷却系统的能量消耗和设备体积。

In the gas hydrate drilling,low-temperature mud could inhibit hydrate decomposition,which was very important to get hydrate samples.Mud cooling system heat exchanger developed by Jilin University selected the co-axial convective heat transfer in cooling mode,and the refrigerant and mud were full reverse current.Mud cooling systems could cool mud rapidly and mud maintained dynamic temperature at a low temperature range,which met the design requirements and played an important role in gas hydrate sampling.In order to provide more effective technical support for hydrate exploration in the future,a three-layer pipe heat exchanger was designed by means of the further research on the heat transfer mechanism and the heat exchanger structure.Heat transfer area and convective heat transfer coefficient were greatly improved.By the theoretical calculations and numerical simulation,the new heat exchanger could increased efficiency significantly to meet the design requirements,using short heat exchanger length could reduced the energy consumption and equipment volume of the system.