【作者】 盖立学；

【导师】 李伯耿；

【作者基本信息】 浙江大学 ， 化学工程， 2002， 硕士

【摘要】 聚合物驱油技术已在大庆油田得到了大规模应用，2001年大庆油田聚合物驱的产油量达到800万吨。随着聚合物驱油技术的实施，大庆油田含油污水油水乳状液的稳定性较以往水驱时显著增强，使得油田已建含油污水处理站的处理能力显著下降，部分含油污水处理站由于处理能力不够造成处理后水质严重超标。由于聚合物驱含油污水中残留的阴离子型聚丙烯酰胺会与水驱含油污水处理中常规使用的阳离子型絮凝剂和混凝剂发生电性中和反应，一方面使所需的加药量显著增大，另一方面所形成的粘附力很强的絮体还会导致含油污水过滤器堵塞，使得在聚合物驱含油污水处理中投加阳离子型絮凝剂和混凝剂的除油效果不好。 本文中通过聚合物驱含油污水水质分析，油水界面活性物质分离及油水分离特性测试，研究了聚合物驱含油污水油水乳状液稳定性的影响因素，确定聚合物驱含油污水油水乳状液的稳定机理主要为胶态固体颗粒吸附到油珠表面上阻止油珠之间的聚并和降低油珠与水相间的密度差，导致油珠上浮速率下降；水中残留的聚合物一方面使胶态固体颗粒容易沉积在油珠表面上，使油珠聚并困难，另一方面也使水相粘度增大，导致油珠上浮速率下降。 本文中针对大庆油田聚合物驱含油污水油水分离难度大的问题，从阴离子型和非离子型药剂的思路出发，研发了对聚合物驱采出液有良好破乳作用且对聚合物驱含油污水有浮选除油功能的油水分离化学剂。室内实验结果表明，聚合物驱采出液中投加20mg/L本文中研发的油水分离化学剂经过1h 45℃热化学沉降后的油相水含量和水相含油量可分别降至2.88％和651.1mg/L；初始含油量为827mg/L的聚合物驱含油污水中投加20mg/L本文中研发的油水分离化学剂经6min浮选后的含油量可降至23.9mg/L。根据所研发的油水分离化学剂的性能，提出了将油水分离化学剂的加药点设在聚合物驱采出液破乳之前，采用热化学沉降—浮选处理工艺解决聚合物驱采出液和含油污水油水分离问题的方法。更多还原

【Abstract】 Polymer flooding has been widely adopted in Daqing Oilfield to enhanced oil recovery. In 2001, 8 million metric ton crude oil was produced by polymer flooding. With the application of polymer flooding, the stability of the inverse oil/water emulsion in produced oily water of Daqing Oilfield has been significantly increased. The tight oil/water emulsion in polymer flooding produced oily water has significantly reduced the treating ability of some old oily water treating facilities. What is worse is that the treated oily water from some oily water treating facilities is seriously out of specification. The reaction between the residual anionic polyacrylamide in the produced oily water and the state-of-the-art cationic flocculant and coagulant has lead to significant increase of flocculant/coagulant dosage, plugging of oily water filters and worse quality of the treated oily water.Stabilization of inverse crude oil emulsion in polymer flooding produced oily water of Daqing oilfield was investigated through water quality analysis, interfacial active particle separation and tests on oil-water separation of both artificial and genuine polymer flooding produced oily water. The enhanced stability of inverse crude oil emulsion in polymer flooding produced oily water primarily results from adsorption of colloidal particles on oil droplets which presents steric hindrance to oil droplet coalescence and decreases the density difference between the oil droplet and the water phase. Residual polymer in polymer flooding produced oily water enhances its stability by promoting deposition of colloidal particles on oil droplet surface and increasing water phase viscosity, leading to lower oil droplet floating velocity. An oil/water separation agent, formulated mainly with nonionic and anionic active components, was developed for polymer flooding produced liquid and oily water. The newly developed oil/water separation agent works well both as demulsifier for o/w type polymer flooding produced crude oil emulsion and as flotation agent for polymer flooding produced oily water. With the dosage of the newly formulated oil/waterseparation agent at 20mg/L, polymer flooding produced liquid can undergo well phase separation after Ih 45C thermal settling, resulting in only 2.88% water in the oil phase and 651.1 mg/L oil in the water phase. With the dosage of the newly formulated oil/water separation agent at 20mg/L, the oil content of polymer flooding produced oily water can be lowered from 827mg/L to 23.9mg/L after 6min induced air flotation. Based on the performance of the newly developed oil/water separation agent, a thermo-chemical settling - flocculation process, in which the newly developed oil/water separation agent is injected inte polymer flooding produced liquid upstream of free water knock-out, was proposed for the oil/water separation of polymer flooding produced liquid and oily water.更多还原