海上油田生产水回注水质指标优化研究——以涠西南油田群为例

Optimization of Reinjection Quality Indicators of Produced Water in Offshore Oilfields:A Case Study of Weixinan Oilfield Cluster

以涠西南油田群为例,在充分分析油田地质油藏特点以及流体配伍性的基础上,开展注入水中悬浮物含量以及粒径中值、含油量、成垢离子含量的指标优化研究。首先对储层岩心渗透率进行精细分级,即细分为(10~50)×10^(-3)μm^(2)、(50~100)×10^(-3)μm^(2)、(100~300)×10^(-3)μm^(2)三个级别,并对各油田推荐适宜的主力注水开发层位。其次,研发优选高效阻垢剂XSZG-2201,通过流体及岩石的配伍性研究,成功获得满足油田现场离子浓度需求的生产水回注定制水质指标。结果表明:涠西南生产水与地层水的配伍性整体较好,阻垢剂阻垢率达到95.73%,通过正交实验,对岩心的综合伤害控制在20%以内。研究结果将为涠西南油田注水开发提供指导,同时给海上及陆上油田注水指标优化提供参考思路。

Taking the the oilfield cluster in southwestern Weizhou as an example,the indicators of oilfield injected water such as suspended solid content,median particle size,oil content,and scaling ion content are studied and optimized based on a thorough analysis of the geological and reservoir characteristics and fluid compatibility of the oilfields.Firstly,the permeability of the reservoir cores is finely divided into three levels,(10~50)×10^(-3)μm^(2),(50~100)×10^(-3)μm^(2),and(100~300)×10^(-3)μm^(2),and the main layers suitable for injecting water development are recommended for each oilfield.Secondly,an efficient scale inhibitor XSZG-2201 was developed,and the customized water quality indicators of oilfield reinjection water that meet the ion concentration requirements of oilfield sites are successfully obtained through the study of the compatibility of fluid to rock.The results show that the compatibility of the produced water to the formation water in southwestern Weizhou is good,the scale inhibition rate of scale inhibitors reaches to 95.73%.Orthogonal test results show that the damage rate of reinjection water to cores is ness than 20%.