Studies On The Formation Kinetics Of Inorganic Scale Of Waterflooding In Oilfield

Scaling is one of the most serious problems during oilfield flooding process.It is crystallized and deposited in the process of flow,because the scale-forming ions arenot only affected by the variation of pressure and temperature but also the thermodynamic instability.Due to the complicacy of scaling process,current experimental study mainly focuses on the thermodynamic analysis.Therefore,it is of significant important to study the effect of formation kinetics of inorganic scale of waterflooding in oilfield scaling prediction and the occurrence of preventing harm.In this paper,the flameion chromatography,titration and spectrophotometry method are used to analyzethe ion of the oil water scaling.The oilfield water scaling is measured by the scaling trend prediction model Oddo-Tomson saturation index method and the saturation coefficient method.The scaling prediction accuracy of Oddo-Tomson saturation index method is better than that of the saturation coefficient method.Multi-component scaling competition and the kinetic equation of scaling process in inorganic scaleare obtained by the ion concentration of the different temperature,pH values,pressures and flow rates measuring by ion chromatography and titration.In addition,The fitted scaling dynamics equation isy = y +Ae.It is beneficial to generate the calcium carbonate scale with the rise of the temperature from the equation.The higher pH value,the easier to form carbonate scale.In general,the scaling is inhibited when the pH value is less than 7.Otherwise,the scaling is promoted when the pH is higher than 7.When the flow velocity is 0.726m·s-1,the degree of water scaling is serious.The increase of pressure has a certain inhibitory effect on the scaling trend of oilfield water.