摘要
聚合物AT-420在大港港东油田新鲜回注污水中的溶液粘度很低,浓度4 g/L时仅为20 mPa.s,为放置20小时的该污水所配同浓度溶液粘度的1/6。AT-420污水溶液的粘度随污水放置时间的延长而增大,前80分钟增速很快,此后增速大大减小。用抗盐聚合物(一种AM共聚物)所作的研究表明,引起溶液粘度降低的主要因素,在港西油田为Fe2+,在羊三木油田为Fe2+和H2S;聚合物盐水溶液粘度随Fe2++Fe3+加入量的变化,证实Fe2+是引起溶液粘度下降即引起聚合物降解的主要因素,配制聚合物溶液用的污水中Fe2+浓度宜低于0.2 mg/L。硫脲和硫代硫酸钠均可减轻污水溶液中聚合物的降解。在港东、港西、羊三木三个注聚站的污水储罐上安装了喷淋装置,使曝气污水中Fe2+浓度大大降低,但曝气污水和用曝气污水配制的聚合物溶液储存12天后,Fe2+浓度又升高。建立了污水通气曝氧—过滤除三价铁化合物—除氧三段处理工艺,建成了包括前两段的处理装置,处理后现场污水中Fe2+浓度稳定地降至0.2 mg/L以下。图6表2。
At Gangdong oil field, Dagang, the viscosity of polymer AT-420 solution prepared in recycled produced water （RPW） as taken immediately is very low, being of 20 mPa·s at concentration of 40 g/L, a value by six times lower than that in RPW aged in open air over 20 hrs, and increases with RPW ageing time fast in initial 80 min and notably slower later. The experiments made with polymer KY （an AM copolymer） indicate that the main factor for the reduction in viscosity of RPW solutions is Fe^2＋ at Gangxi oil field and Fe^2＋ and H2S at Yangsanmu oil field and the conclusion that Fe^2＋ is responsible for the reduction in polymer solution viscosity, or for the polymer degradation in RPW solutions, is verified by the changes in viscosity of polymer solutions in salt water with Fe^2＋ or Fe^3＋ added in various amount; the Fe^2＋ concentration in the RPW for preparing flooding polymer solutions should be 〈 0.2 mg/L. Thiourea or sodium thiosulfate can reduce polymer degradation in RPW solutions. A spray head has been installed on RPW tanks at Gangdong, Gangxi, and Yangsamnu polymer injection stations, the Fe^2＋ concentration was lowered significantly in the RPW exposured to air in the course of spray but raised again in the exlmsured RPW and in the polymer solutions prepared with the RPW after standing over 12 days. A three-stage treating technolcgy aeration-filtration of Fe（ Ⅲ ） compounds-oxygen scavenge is established for the RPW used in preparing polymer solutions and a treating installation of the first two stages is put into operation to produce treated RPW with Fe^2＋ concentration being of 〈0.2 mg/L steadily.
出处
《油田化学》
CAS
CSCD
北大核心
2005年第2期158-162,共5页
Oilfield Chemistry
关键词
回注污水
溶液配制
聚合物溶液
化学降解
二价铁离子
污水处理工艺
曝气处理
大港油田
recycled produced water
solution preparation
polymer solution
chemical degradation
ferrous ion
wastewater treating technology, air exposure
Dagang oil fields
