水泥浆与泥浆比热的室内研究

LABORATORY STUDY ON HEAT CAPACITY OF CENMENT SLURRY AND DRILLING FLUIDS

井下循环温度是影响注水泥能否成功的关键因素之一 ,要准确计算循环温度 ,除了建立与井下实际情况吻合的模型外 ,还必须准确给出水泥浆、泥浆的热物性数据。首先根据测量液体比热的电流量热器法原理自制了测量装置 ,然后分别测量了 15种水泥浆、5个密度的两类泥浆在 7个温度范围下的比热 ,最后分别分析了水泥浆与泥浆的组份、密度以及温度的变化对水泥浆和泥浆比热的影响。结果表明 :在相同密度温度条件下 ,水泥浆、泥浆组份不同时 ,其比热不同 ;同组份的水泥浆和泥浆 ,在任何温度下 ,水泥浆、泥浆比热随密度减小而增大 ;对任何水泥浆、泥浆 ,其比热随温度升高而增大 ;一般在相同密度和温度条件下 。

The circulating temperature is one of key factors that determine whether cementing is successful. In order to calculate the circulating temperature accurately, thermal physical property data of the cement slurry and drilling fluids have to be given exactly besides setting up mathematical model corresponding with reality in the wellbore. Firstly, a measuring device of heat capacity was developed according to electric current calorimeter method that is used to measure heat capacity of a liquid. Secondly, heat capacity at seven-temperature scope was measured for fifteen kinds of cement slurry and two kinds of drilling fluids with five densities. Finally the influences of composition, density and temperature of the cement slurry and drilling fluids on the heat capacity were analyzed. Results indicate that the heat capacity is different at the same density and temperature when the composition of the slurry and mud is not identical; the heat capacity increases at any temperature when the density of the slurry and mud in the same composition reduces. For any cement slurry and drilling fluids, the heat capacity increases with temperature. In general, the heat capacity of drilling fluids is higher than that of cement slurry.