鄂尔多斯盆地地层水的配伍性研究

Compatibility Research of Stratum Water in Ordos Basin

水平井体积压裂技术是致密油气藏高效开发的关键技术。为了合理地处理鄂尔多斯盆地长7采出水及避免油井水淹,通过对水质离子含量分析、失硫酸根率、结垢量和垢型的分析,研究了陕北油田长7和延10地层产出水的混合结垢性质,探索了上述混合水样回注延10地层的可行性,得出了可回注地层的长7与延10地层产出水最佳混合比例。结果表明:长7与延10地层水以8:2比例混合时,失硫酸根率与结垢量达到最高;混合水与延10地层水以9:1的比例混合时,失硫酸根率与结垢量为最低;经过絮凝处理的混合水悬浮物含量、含油量分别降至为1.0,2.50 mg/L,达到SY/T 5329—2012《碎屑岩油藏注水水质指标及分析方法》的要求。

Stimulated reservoir volume fracturing is one of the most significant ways to enhance the recovery of tight reservoir.For safe disposal of Chang 7 stratum water,mixed water properties of Chang 7 and Yan 10 stratum water in shanbei oilfield was studied in terms of ion content test,sulfate loss rate study,scale and scale type analysis respectively.The best mixed ratio for reinjection was achieved.It was shown that Chang 7 and Yan 10 stratum water belonged to highly mineralized sodium bicarbonate type.When the mixed ratio of Chang 7 to Yan 10 stratum water is 8 ' 2,the highest sulfate loss rate and amount of scale(56.76%and 376.6 mg/L,respectively)were achieved.When the mixed water was remixed with Yan 10 stratum water at volume ratio of 9:1,the lowest sulfate loss rate and amount of scale(1.19%and 0.33 mg/L,respectively) were obtained.The amount of suspension content and oil content of the processed mixed water were decreased from 2.00 mg/L and 6.67 mg/L to 1.00 mg/L and 2.50 mg/L,which met the standard of reinjection water.