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Along with exploratory and development of petroleum,to adapt the demand of modern drilling technology,such as speed up drilling rate,cut cost,etc,the manufacturers developed an advanced ,smaller size,lighter mud pump. Through survey we can find that the mud pump has already been developed in large power,large displxcement and high pressure. Current hydraulic parameters design are based on low mud pump behavior,when performance parameters are improved,present method can be modified appropriately.In order to calculate the circulating wellbore temperature field exactly, thermal conductivity and specific heat of polymer drilling fluid and sulphonated polymer mud was experimentalized by using measuring instrument of drilling fluid’s thermal properties,and the influence on wellbore temperature counting resulted from variation of drilling fluid’s specific heat and thermal conductivity was also analyzed. Two kinds of drilling fluid’s Thermophysical parameters’s relationship with temperature was obtained, and the two kinds of thermal properties’computing formulas at different temperature were also fitted.In deep or ultradeep well well,, mathematical model was established in order to wellbore temperature and pressure field considering pressure and temperature’s influnce on drilling fluid parameters, then the pressure loss can be obtained,the base of hydraulic parameters design can be settled.The mud pump has already been developed into large power, large displacement,and high pressure now,but field devices ,such as pipeline, drilling strings, have limited bearing pressure capacity, according to the transmission power relationship, formula of hydraulic parameters design was obtained , variation range of minimum carrying cutting displacement was calculated,the influence of different limiters on drilling bit’s water power was analysed,By coding the program and simulating the law of drilling bit’s water power under different conditions,we can build a new way of hydraulics parameters optimization .
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