The Effect Of Produced Water Ions On The Crystallization Process Of Calcium Carbonate

The oil field in our country has entered the period of high water cut,and the oil field has the characteristics of"four high and one low",namely the high degree of salinity;high temperature of the extracted water;high content of bacteria and suspended solids;The PH is lower.This makes the scale of the collection pipe more serious,and the most common scale in the pipeline is calcium carbonate scale.At present,the research on the scale behavior of calcium carbonate microcrystalline is also focused on the qualitative study of thermodynamics and the lack of quantitative crystallization kinetics.Coordination titration method was used to study the influence of the ion of calcium carbonate in produced water solubility,results show that the common ion including Na⁺,K⁺,Mg²⁺has obvious solubilization effect on the solubility of calcium carbonate,exist the best promote the concentration of dissolved,before the best promote the dissolved concentration,with the increase of adding ion concentration,increase the solubility of calcium carbonate,over the best promote the dissolved concentration,promote the dissolution effect gradually becomes poor.Moreover,the effect of ionic acid on the solubility of calcium carbonate is not only related to ionic strength,but also related to the interaction between ions.Use of pure acid-base titration respectively research system and simulated oil field produced water systems,calcium carbonate crystallization kinetics,and explore the ion from the angle of activation energy and the scale inhibition rate effect on the crystallization process,the results show that Mg²⁺on the crystallization process of calcium carbonate is significant,the influence of pure activation energy in the system is82.414 kJ/mol,simulated oil field produced water system activation energy of 151.548kJ/mol,to inhibit the reaction of the produced water ions.By scanning electron microscopy?sem?to test the calcium carbonate crystal under different growth conditions,the results found that Mg²⁺made the morphology of calcium carbonate crystals into irregular shapes by regular rhomboids.This may be the result of a dramatic change in the growth rate of the three dimensions of calcium carbonate.