Prediction of CaCO3 scaling in water injection wellbore

This paper conducts a study on the CaCO3 scaling in water injection wellbore. With the combined effect of fluid flow and heat transfer on scaling taken into consideration, a mathematical model for predicting the scaling of CaCO3 was developed, which is based on the model for the calculation of deposition and removal mass rates. The scaling prediction software of water injection well was developed. The software was used to predict the scaling in a water injection wellbore of low permeability reservoir in Shengli Oilfield. The prediction result is in good agreement with measurement result. It is also found that the scale layer thickness increases with the increase of water injection time and scale-forming ions concentration, while it decreases with the increase of daily water injection rate. As a consequence, in order to reduce scaling in the wellbore, it is reasonable to shorten the water injection times, increase water injection rate and purify the injection water.