Development and Application of ZLZY310 High Temperature Drilling Fluid Cooling System

To solve the problem of inaccuracy of MWD instruments caused by downhole high-temperature environment,ZLZY310 high-temperature drilling fluid cooling system was developed.Based on the heat exchange theory,the influence of the drilling fluid entry temperature on the temperature of downhole drilling fluid was analyzed and the temperature change of the drilling fluid when it is still was considered,the technical parameters of the cooling system were determined.With plate heat exchanger,the heat exchange efficiency of drilling fluid cooling system is over 85%.The heat-exchanged water is dissipated by several sets of cooling towers,which work based on the principle of air cooling and evaporation.The backwashing process of drilling fluid was designed,which can solve the problem of pipe plugging by impurities in drilling fluid.The drilling fluid cooling system has been applied in the oil field,and the processing capacity of drilling fluid reaches up to 150～260 m³/h,which has obvious cooling effect compared with similar cooling devices.The circulating cooling capacity of drilling fluid meets the requirements of field operation and reduces the influence of formation temperature on downhole tools.The research results provide effective technical support for drilling fluid cooling and backwashing processes during drilling.