延安组与延长组污水混合结垢规律实验

Experimental study on scaling law of sewage in Yanan formation and Yanchang Formation

油气田开发过程中,产生了大量含油污水,这些污水处理达标后可用于回注。但不同来源含油污水水质差别较大,不同类型的污水相互混合,其中的离子容易发生沉淀反应而结垢。因此,研究污水混合结垢规律是有必要的。根据延长油田实际污水中所含离子的性质特点,模拟配制延安组、延长组污水,按一定的比例混合评价结垢情况。实验结果表明,当延安组污水与延长组污水混合比例为1∶9时,结垢量最小,结垢量均小于500 mg/L。随着延安组污水混合比例的增大,产生的垢量也在逐渐增大。当延安组与延长组污水混合比例为7∶3时,结垢量最大,结垢量均大于1700 mg/L。所以油田现场污水混合时,应避免延安组与延长组污水按7∶3比例混合。

During the development of oil and gas fields,a large amount of oily sewage has been produced,which can be used for reinjection after reaching the standard.However,the quality of oily sewage from different sources is quite different.Different types of sewage mix with each other,and the ions in the sewage are prone to precipitation reaction and scaling.Therefore,it is necessary to study the law of fouling and scaling.According to the characteristics of ions in the actual sewage of Yan’an Oilfield,the sewage of Yan’an and Yan’chang Formations was simulated and scaling was evaluated by mixing in a certain proportion.The experimental results show that when the mixing ratio of Yan’an group sewage and Yanchang group sewage is 1∶9,the fouling amount is the smallest,and the fouling amount is less than 500 mg/L.As the proportion of sewage in Yanan formation increases,the amount of fouling is increasing.When the mixing ratio of Yan’an group and Yanchang group was 7∶3,the fouling amount was the largest,and the fouling amount was more than 1700 mg/L.Therefore,the mixing of the sewage from the Yanan group and the Yanchang formation should be avoided according to the 7∶3 ratio when the oilfield sewage is mixed.