拜城盆地北部洪积扇砂砾石包气带石油类和CODMn的运移分析

Analysis of Petroleum and CODMn Migration in Vadose Zone of Sand Gravel from Alluvial Fan in Northern Baicheng Basin

拜城盆地将建成一座年产60× 108 m3/a的天然气处理站,为应对天然气处理站在突发石油类和污水泄漏可能污染地层和地下水的情景,根据建设场地地质、水文地质条件,建立了2种地层结构概念模型,在此基础上建立了一维垂向饱和-非饱和土壤水流数学模型与考虑土壤吸收的饱和-非饱和土壤溶质运移数学模型.应用HYDRUS软件求解非饱和带中的水分与溶质迁移方程,对石油类和CODMn在非饱和带中向下垂向运移过程中进行模拟.模拟结果表明:克深油气处理厂区分布的粘土层将有效阻止污染物向下运移,为避免由于天然气处理厂建设和运行导致污染物进入地层中,装置区防渗最高等级的渗透系数可以不超过10-7 cm/s.

Baicheng basin will built a seat annual 60× 108 m3/a of gas processing station,in order to answerable for oil class and sewage leak may pollute formation and groundwater in gas processing station,according to geological construction site,and hydrological geological conditions,established 2 species formation structure concept model,and established one dimension vertical saturated-non-saturated soil flow mathematics model and considered soil absorption of saturatednon-saturated soil solute shipped moved mathematics model,solving equation of water and solute transport by HYDRUS software in unsaturated zone for oil and CODMn.Simulation results show that clay layer distributed in Keshen oil and gas processing plant will effectively prevent the downward migration of pollutants,the highest permeability coefficient in the seepage control of devices can not exceed 10-7 cm/s in order to prevent pollutants get access to the strata.