Estimation of potential barium sulfate (barite) precipitation in oilfield brines using a simple predictive tool

Scale deposition is one of the most important and serious problems that limits and sometimes blocks oil and gas production by plugging the oil producing formation matrix or fractures and perforated intervals. One of the most insoluble substances formed from formation water (brine) and one that is very difficult to remove once formed on equipment, formation matrix or fractures and perforated intervals is barium sulfate. It is so insoluble that quantitative analysis methods for both barium and sulfate are based on the precipitation of barium sulfate. In this work a simple-to-use predictive tool is developed to estimate potential barium sulfate (barite) precipitation in oilfield brines that are predominantly sodium chloride solutions as a function of sodium chloride concentration and temperature. Estimations are found to be in excellent agreement with reported data in the literature with average absolute deviation being <1.3%. The tool developed in this study can be of immense practical value for experts and engineers to have a quick check of barium sulfate scale formation at various conditions without opting for any experimental trials. In particular, petroleum and process engineers would find the approach to be user-friendly with transparent calculations involving no complex expressions. (c) 2012 American Institute of Chemical Engineers Environ Prog, 32: 860-865, 2013