【作者】 刘义刚；

【导师】 赵立强；

【作者基本信息】 西南石油大学 ， 油气田开发工程， 2013， 博士

【摘要】 污水回注是维持渤海石油资源持续开发与环境保护之间协调发展的重要措施,然而目前海上油田经注聚后所产生的含聚污水在回注时面临众多问题,如：水质状况差,注采比低,注水量达不到配注要求；注水井措施有效期短,层间矛盾突出；含聚污水乳化程度高,油水分离困难,没有配套的高效污水处理药剂。这些问题严重制约了含聚污水的回注,也同时限制了海上石油的开采。本文以渤海SZ36-1油田、LD10-1油田、JZ9-3油田含聚污水回注的共性问题为研究对象,以含聚污水高效、经济、持续回注为目标,首先在线监测和分析了上述三大油田的污水处理情况及注入水水质情况,同时开展了含聚污水与储层适应性程度的研究,确定了回注水质指标；然后,通过分析含聚污水的组成及特性,搞清楚了含聚污水的稳定机制,并在此基础上有针对性地研制出了适用于含聚污水的处理剂体系；经过优化和调整污水处理系统后,最终实现了含聚污水的达标回注。在线水质监测表明上述三油田的污水处理效果及注入水水质受产出聚合物的影响明显,严重超标。这些含聚污水回注后会造成一定程度的储层伤害,其机理主要为药剂不溶或者不相容产生的沉淀、药剂对残余聚合物絮凝；其次为腐蚀与结垢产物、清污不配伍产生的FeS等沉淀,残余聚合物与含油乳化堵塞对储层不会造成永久性堵塞。通过考察污水中悬浮物浓度和粒径中值、含油率及聚合物浓度等因素对储层的影响,推荐了LD10-1油田、SZ36-1油田、JZ9-3油田含聚污水回注的水质标准。通过分析含聚污水的组成特点、研究聚合物水相粘度对油水分离速度的影响、聚合物在油水两相的分配系数以及聚合物对油水界面电荷和扩张粘弹性的影响,发现含聚污水稳定的原因有两方面：一是随着注聚的进行,污水中极性大的油组分含量增加；二是产出聚合物吸附在油珠界面,导致油珠Zeta电位及油水界面膜强度增加,影响油珠的聚结与聚并,从而大大提高污水的稳定性。根据这一原因及药剂的矿场使用要求,本文设计并构建出以DAC为阳离子单体、MOA为乳化剂、V50为引发剂的乳液聚合体系,通过单因素及正交实验优化出乳液型污水处理剂的最佳合成配方及反应条件,并完成了规模从500kg及1000kg的逐级放大生产试验。矿场使用可使核桃壳出口污水含油低于30mg/L,固体悬浮物含量为4.2mg/L、粒径中值为1.627μm。另外,在系统研究含聚污水对污水处理系统性能影响的基础上,优化了斜板除油器、气体浮选器等性能参数,大幅度提高了设备对含聚污水的处理性能和效率；研制出适合海上平台的清水除铁技术在矿场试验成功应用,以及配套的、性能优良的阻垢剂和缓蚀剂。最后,本文提出了水质分级控制,实现了海上油田含聚污水的高效回注,为化学驱产出污水回注提供了技术保障。更多还原

【Abstract】 Reinjection of wastewater is the most important technique for keeping the balance between continuable exploitation of oil in Bohai oilfield and environment protection. Howerver, there are several problems for the reinjection of wastewater produced polymer flooding (WPPF) after the performance of polymer flooding in several offshore oilfield, as follows:(1) the bad water quality, low ratio between injection and recovery, and the amount of inject water is far from the demand.(2) the period of validity of water injection is not long enough and the conflict between the different horizons is obvious;(3) the degree of the emulsification of water and oil is high and is difficult to be treated, and there is no effective treating compound for now. Theses problems seriously limit the effective rejection of WPPF and the exploitation of oil in Bohai oilfield.In this paper, the common problems of rejection of wastewater produced from polymer flooding in Bohai SZ36-1oilfield, LD10-1oilfield and JZ9-3oilfield were studied. For the effective, economic and continuable reinjection of WPPF, the monitoring of the water quality in time in these oilfields was developed firstly. At the same time the degree of adaptability of between WPPF and reservoir was studied and the indexes of the reinjection of WPPF was made. Then, the characteristic compose of WPPF was analyzed and the mechanism of the stability of the WPPF was discussed. On the basis of the mechanism of the stability of the WPPF,a new effective treating compound for WPPF was prepared. At last, after the optimization and adjustment of the system of wastewater treatment, the effective rejection of WPPF was realized and the demand of reinjection was met at the same time.The results the monitoring of the water quality in time showed that the water quality was above the standard seriously and the treatment of the WPPF and the water quality were affected the polymer obviously. The reinjection the WPPF would destroyed the reservoir and the reasons were as follows:(1) there were precipitation caused by the incompatibility between the treating compounds;(2) there were production of corrosion and crustation and FeS;(3) the permanent blockage of caused by the residual polymer and emulsion reservoir. The effects of the concentration of suspended solid, size of the suspended solid, concentrations of oil and residual polymer on the destroy of reservoir were studied and a new standard of rejection of WPPF was established.After the analysis of characteristic composes in WPPF and study of the effect of residual polymer on the stability of the WPPF,the reasons for the stability of WPPF were found. There were two main reasons:(1) the amount of polar composes in water increased with the oil concentration in water;(2) the adsorption of the residual polymer on the interface between oil increased the strength of the interfacial film and the affect the floating of the oil.On the basis of the two reasons, a new polymer emulsion containing the AM, DAC and MOA was prepared. After the optimization experiment of several conditions, the best treating compound for the WPPF was get. After the treatment of WPPF by this treating compound, the oil concentration in water was30mg/L, concentration and size of suspended solid were4.2mg/L and1.627μm, respectively.In addition, on the basis of systemic study of the effect of WPPF on the treatment the system of wastewater treatment, the performance parameters of shew slab oil remover and flotator were optimized and their performance and efficiency were improved. At the same time, the technique of the remove of iron ion was successfully used in the offshore oilfield and corresponding antiscale and corrosion inhibitor were prepared.At last, the step control of water quality was proposed and the effective rejection of WPPF was realized. Theses results supplied the guarantee of the rejection of the wastewater produced from the chemical flooding.更多还原