Radiological Hazards Assessment of Produced Water from Some Oil and Gas Flow Stations in Delta State, Nigeria

Abstract

The radiological hazards of produced water collected from seven oil and gas flow stations (fields onshore) of Delta State, Nigeria were estimated using thallium activated 3”x3” Sodium iodide [NaI(TI)] detector. Twenty- one samples of produced water from seven flow stations waste pit were collected within the oil fields using standard methods. From the radionuclide results, the radiological hazards were computed.  Comparing the computed average values for representative gamma index, annual effective dose equivalent (Outdoor) annual effective dose equivalent (indoor) which are 0.104 mSv/y, 0.0229 mSv/y and 0.03276 mSv/y respectively with the standard of 1.0 mSv/y, it was observed that the results are all below the recommended limit. The computed absorbed dose rate ranged from 4.570 nGyh−1 to 10.088 nGyh−1 with an average value of 6.68 nGyh−1 was found to be higher than the acceptable standard of 1.5 mSvy-1. The results obtained in this study provides a baseline map of radiological hazard levels of produced water that may likely be discharge in to the environment and may be used as reference information to assess any changes in this studied area. This subject is important in environmental radiological protection since produced water are widely been discharged in the environment during oil and gas productions.