Study On The Influence Of Centralized Treatment Facilities For The Waste In Oil Fields On Groundwater Environment

At present,the issue of regional groundwater environment security caused by the exploitation of large-scale oil and gas has gradually became a hotspot to scholars from many country.The exploitation of oil and gas will produce many kinds of waste,which are harmful to the environment.In order to ensure the steady development of the oil and gas industry,avoid the adverse effects of oil field exploitation,we need to disposal the wastes from oil and gas fields centralized.This paper takes the waste disposal project of an oil field in Ordos as an example.Analyzes the projects of oil field exploitation,clarifies the main kinds of pollutants,which have an adverse effect on groundwater during the oil field exploitation.According to the natural geography,geology,hydrogeology,groundwater exploitation and utilization status of the area under the waste concentration treatment facility,We construct the mathematical model,numerical model and the solution of main pollutant model,predict the impact on the groundwater during the operation of waste disposal facilities.Conclusions are as follows:This paper analyzed the exceeding range,influence range and the concentration change trend of the pollutant by selecting the priority pollutant.It can be found that the pollution degree of COD and oil in the upper layer is obviously greater than that in the lower layer due to the accidental release of pollutants in unconfined aquifer.The COD concentration exceeded the standard before 100 days,the maximum concentration is 3.0mg/L,and the superstandard range is 2400m2.After 100 days,the maximum concentration is 0.5mg/L.The concentration of petroleum pollutants exceeded the standard before 1000 days,among which the maximum concentration before 100 was 3.0mg/L,exceeding the standard by 8000m2.The maximum concentration of petroleum pollutants was 0.05mg/L between 100 days and 1000 days,exceeding the limit by 20800m2,and 0.03mg/L after 1000 days.The accidental release of COD and oil pollutants in a short period of time will have certain pollution effects on groundwater environment,but the impact is limited,only distributed in the downstream area of the pollution source;With the dilution and diffusion of groundwater,the pollutant and concentration at the center of the pollution halo migrate southwest along the groundwater flow direction in a gradually decreasing manner.Within 7,300 days of the release,the pollution has not affected residential wells with the time goes on,under the influence of groundwater dilution and other effects,the concentration and range of pollutants are gradually reduced.