The purpose of this project is to determine the solubility of BaSO4 in temperature and pressure ranges that have not been investigated carefully in the past. In addition, the scaling tendency of BaSO4 in typical North Sea wells will be analyzed using the ScaleCERE software.
BaSO4 solubility in pure water and in NaCl solutions under various temperature and pressure conditions has previously been measured and published. There is relatively good agreement between data from different sources with a few important exceptions:
At temperatures between 100 and 200 °C at the vapor pressure of water, there are significantly diverging trends between the two sources of data available for BaSO4 solubility in pure water.
For BaSO4 solubility in NaCl solutions at pressures between the water vapor pressure and 500 bar, there is only one source available. The data from this source are inconsistent with data at higher and at lower pressures.
The objectives of this project are:
OB1: Reproduce existing low pressure solubility data for BaSO4 in water and brines.
OB2: Measure BaSO4 solubility in pure water at temperatures up to 200 °C to establish the correct solubility of BaSO4 in this temperature range. Existing equipment is used.
OB3: Design and build a cell for solubility measurements at pressures up to 500 bar and temperatures up to 200 °C.
OB4: Measure BaSO4 solubility in NaCl solutions under pressures up to 500 bar.
OB5: Measure BaSO4 solubility at relevant reservoir conditions. The measurements will be carried out at temperatures, pressures, and compositions similar to reservoir conditions.
OB6: Compare measured data with ScaleCERE calculations. Fine tune model parameters using the measured data if necessary.
OB7: Determine conditions which gives a tendency for BaSO4 to form under typical North Sea conditions using the ScaleCERE software.
Related Phd project: Kinetics of scale formation in oil and gas production, Petter Lomsøy