龙王庙气田水地面处理达标外排工艺应用评价

Application evaluation the process of ground treatment and standard discharge for Longwangmiao gasfield water

龙王庙组气藏气田水矿化度较高,并含有氯化物、H2S、CO_(2)、悬浮物和有机物等污染物,高压回注存在安全风险及回注井环评审批难度日益增大。根据龙王庙气田水水质特点,采用“氧化脱硫+微电解氧化+MVR蒸发结晶”工艺处理气田水,对每个阶段水质取样进行分析和效果评价。试验结果表明,该工艺具有提高废水的可生化性、除重金属、除硫化物、除氯化物、除磷化物、脱色和降低水中COD等特性,出水水质能满足《污水综合排放标准》(GB 8978-1996)一级标准和《四川省水污染物排放标准》(DB 51/190-93)一级标准,可以实现气田水地面处理达标外排,所得产物结晶盐能达到工业盐中湿盐优级标准,具有工业化推广应用价值。

The gasfield water of Longwangmiao formation gas reservoir is highly mineralized and contains pollutants such as chloride,H2S,CO_(2),suspended solids and organic matter.There are safety risks in high pressure reinjection and it is increasingly difficult to review and approve the reinjection well ring.According to the water quality characteristics of Longwangmiao gasfield water,the process of"oxidation desulfurization+micro-electrolysis oxidation+MVR evaporation crystallization"was used to treat the gasfield water,and the water quality of each stage was analyzed and evaluated.The results show that the process can improve the biodegradability of wastewater,remove heavy metal,sulfide,chloride,phosphide,decolorize and reduce COD.The outlet water quality of the process can meet the first class standard of integrated wastewater discharge standard(GB 8978-1996)and the first class standard of water pollutants discharge standard of Sichuan Province(DB 51/190-93).Theground treatment of gasfield water can meet the discharge standard,and the product crystalline salt can reach the superior standard of wet salt in industrial salt.The process has industrial application value.