油田回注污水三项水质指标检测方法研究

About Determining Methods for Three Characteristics of Recycled Produced Water Quality

胜利油田按照行业标准SY/T 5 32 9 1994检测油田回注污水特别是精细过滤水水质时 ,发现某些指标测定值误差较大或不能反映水质好坏。悬浮固体含量测定误差来源于水质的不稳定性 ,通过避氧取样、水样密闭及添加稳定剂可得到准确的测定结果。含油量测定中 ,汽油萃取法只适用于含油量大于 10mg/L的污水 ,精细过滤水含油量低 ,建议用石油醚萃取 ,在波长 2 2 5nm处测紫外光的透光度 ,求得含油量。粒径中值反映水质好坏有局限性 ,建议增加水样中固体颗粒总数和颗粒直径数量分布两项指标 ,并根据注水地层物性参数判定水质是否合格。图 2表 3。

The quality of purified recycled produced water is appraised according to the trade Standard SY/T 5329 1994 in Shengli and it is found that the determinations of some water quality characteristics are errorous in some cases or do not represent the real water quality, especially after fine filtration. The errors in determinations of suspended solids content in the water samples originate from unstable water quality and accurate values can be obtained after taking following measures: sampling under oxygen free conditions, maintaining water samples hermetic and adding a proper water quality stabilizer. To determine oil content in the water samples gasoline can be used as extractant only when oil content in the water samples is >10 mg/L; the injection water after fine filtration contains much less oily substances and in this case petroleum ether is recommended as extractant and oil content in water samples is to be determined from ultraviolent absorbance of the extract at 225 nm. The characteristic median particle size d 50 represents water quality with great limiatations and it is suggested to determine 2 additional characteristics: total particle number and number distribution of particle size and to assess the water quality according to the physical parameters of the reservoir to be water flooded.