Utilisation of Oyster Shells Powder for Modification of Acidic Oilfield Produced Water for Reuse and Re-injection

Oysters are bivalve mollusks primarily found around the coastal areas. However, oyster shells are indiscriminately disposed of causing many negative effects on the ecosystem. This study aims to increase its recycling awareness through the utilization of the shells to adjust the pH value of acidic produced water samples C7T, AZ-ST1 & AZ-ST 2 collected from an oilfield in Bayelsa State, Nigeria for reuse and reinjection. Oyster shells were pulverized and characterized using the FTIR technique. The performance of the pulverized oyster shells (POS) was tested for pH modification of produced water for reinjection by using 100g and 200g of the POS placed in a column and allowing 200mL of the untreated produced water samples to pass through each set up and varying contact time (30, 60 & 90 min). The pH level of the UPW samples gradually increased from 6.3-6.5 to reach 8.2-8.5 after 90 min. The study suggests that POS is a potential and sustainable alternative agent for modifying the pH of reinjected produced water to prevent scale formation, corrosion of facilities and reservoir plugging.