Influence of Hydrodynamic Conditions on Precipitation Kinetics of Barium Sulfate in a Multifunctional Reactor

In this paper, the influence of hydrodynamic conditions in Kenics static mixer, which acts as a multifunctional reactor, on precipitation kinetics of barium sulfate is investigated. The investigated range of the Reynolds number varied between 500 and 5000, which covered both laminar and turbulent flow regimes. In all experiments, the relative supersaturation was maintained at the constant level (s = 205). The obtained precipitate was collected and used for crystal size distribution (CSD) determination. On that basis, the kinetic parameters of the process were calculated using the mixed suspension mixed product removal (MSMPR) mathematical model of the process. It was found that for the whole investigated range of Reynolds number, the mixing conditions were satisfactory. CSD analysis showed that in the laminar regime, a clear tendency in crystal behavior could not be noticed. However, during the analysis of the turbulent regime, the presence of a critical Reynolds number was noticed. Above this value, there is a change in the flow pattern, which results in a change of kinetic parameters (B, G), as well as manifests in a form of a decrease in the value of mean diameters of crystals. The flow pattern change is caused by the geometry of the reactor’s inserts.

The Impact of Sulfate Level Reduction on Seawater Injection Economics: Using Sulfate Scale Precipitation Kinetics to Our Advantage

ADNOC Onshore plans to use seawater as alternative to aquifer water, its source of injection water for over 40 years. However, using seawater for injection introduces a sulfate scaling risk due to incompatibility with formation water. Sulfate in the seawater and cations in the formation water (Ca, Sr) are likely to precipitate, causing scaling and related flow assurance problems and formation damage. Sulfate can be removed from the injection water by means of desulfation, but sulfate removal to well below its scaling concentration is CAPEX intensive and negatively impacts seawater flooding economics. In this paper, the economic benefits of partial sulfate reduction are evaluated, by finding a balance between controllable scaling and costs for inhibition and sulfate removal.