Oil asset and production integrity

The Spill Incident data is a log for recording information on oil spill incidents, based on the Joint Investigation Visit findings. In accordance with the guidelines for sustainability reports issued by IPIECA, the Spill Incident Data table is updated on a monthly basis and contains all events registered with a quantity of oil spilled strictly above 1 barrel. Joint Investigation Visits (JIV) are conducted by teams comprises of NAOC JV, and Government Regulatory Agencies (GRA),  National Oil Spill Detection and Response Agency (NOSDRA), State Ministry of Environment (SMENV) & Community representatives. The JIV team visits the incident site to confirm the cause of spill through visual observation and Ultrasonic Thickness Measurements (UTM) to determine the quantity of oil spilled through quantitative assessment which normally includes the extension of area impacted and the thickness of oil, as well as porosity of soil (when applicable).

The clean-up method employed by NAOC JV for the clean up of oil impacted sites involves the following:

• Skimming, recovery and transportation of all free-floating oil from the spill site to the nearest company crude oil facility or company approved treatment site for incineration;
• Cutting/clearing of oil stained vegetation from the impacted area where necessary and transportation of the waste to a treatment site for incineration;
• Scraping, gathering and transferring of all contaminated soil/oily waste to an incineration site;
• General tidying up of the entire impacted area is carried out to the extent that there would be no oil on sediments or visible oil sheen on water;
• After the clean-up is completed, a Post Clean-up Inspection (PCI) is carried out with Government Regulatory Agencies (GRA) where samples are collected for analysis. The site is closed-out if the results of the analysis indicates that no further remedial action is required. There is regular monitoring of the spill site by NAOC JV during the clean-up activities to ensure that the clean-up is executed in line with the scope of work and regulatory standards.
  

NAOC JV remediates contaminated sites (soil) using Remediation by Enhanced Natural Attenuation (RENA), which is an integrated use of Bioremediation and Land-farming techniques. The principle for the application of RENA is based on the fact that the hydrocarbon compounds in the spilled oil undergo biodegradation under suitable bio-physico-chemical conditions. Under RENA, various forms of activities promote these conditions, and the hydrocarbon compounds biodegrade gradually to give rise to CO2, H2O and biomass

The RENA process involves the following:

• Site assessment: Surface visual inspection of the site, sampling (sample collection and analysis, results of analysis).
• Site preparation:  Clearing of the site is done manually by cutting down and clearing dead logs for easy accessibility.
• Soil preparation: Tilling and homogenization of impacted soil aimed at exposing the impacted soil to atmospheric aeration.
• Construction of ridges: Construction of ridges in a windrows fashion to expose deeply contaminated soil to the surface for aeration and eventual attenuation through biodegradation.
• Soil amendment:  Nutrients application to contaminated soil to enhance the biodegradation and the quality of the soil.
• Monitoring:  The area will be monitored for a period of four months after soil amendment and samples collected and analyzed.
• Project close out: Site to be closed out only when plants and vegetation have regenerated and the Total Petroleum Hydrocarbons (TPH) and other contaminant levels have reduced in line with the Nigerian standards.