Abstract
A study was initiated to investigate impact of co-mingling produced water with seawater. The objective of the study was to assess injectivity decline in power water injectors caused by introducing produced water into the seawater injection system using core samples from Arab-D.
A series of core flood experiments was conducted to study formation damage aspects. The core flood study was done using water samples collected from shipping lines from Qurrayah to represent seawater and produced water from HRDH GOSP-2, due to lack of actual produced water from X field. The core flood experiments were performed to assess the effect of produced oily water on core permeability.
Experimental results showed that introducing different ratios of produced water (5, 10, 15 and 100 vol.%) to the seawater resulted in permeability loss of core samples. The damage was found to be proportional to the concentration of produced water. More reduction in permeability was found in low permeability core samples. However, lost permeability was restored by reversing flow in high permeability core (83 md).
Based on the obtained results, it is recommended to inject produced water into a dedicated disposal wells to avoid any injectivity decline in power water injectors and to maintain the injection rate target of 30 MBWPD. It is also recommended to maintain a good quality of the injected seawater. Low level of oil and solids in produced water should also be maintained.
