【作者】 李晓娟；

【导师】 陈立宇； 齐小峰；

【作者基本信息】 西北大学 ， 化学工程， 2019， 硕士

【摘要】 随着全球原油需求量的不断攀升,保护油井、提高原油采油率成为全球热点话题。天然高分子物质淀粉,具有价格低廉、来源广泛、绿色可降解等特点,改性后的淀粉类物质由于其结构的特殊性,很早便应用于石油天然气行业,并广泛研究。本文首先对国外原样进行剖析检测,确定主要成分。其次以玉米淀粉、丙烯酰胺和丙烯酸钠为合成原料,过硫酸铵-无水亚硫酸氢钠为复合引发剂,采用水溶液聚合法,制备可用于石油开采注剂的共聚产物。我们筛选了不同淀粉原料,并讨论了合成条件如:单体NaAA加入量、引发剂用量、反应时间以及反应温度对聚合反应的影响。从共聚物表观粘度、单体转化率、接枝率的结果考察了合成条件的影响,得到最佳制备条件为:NaAA加入量为0.3 mol/L、引发剂用量为单体总质量的3%、反应时间3 h、反应温度50℃。使用Box-Behnken中心组合建立数学模型,根据预测模型得到各因素对表观粘度的显著性从强到弱依次为:反应温度>引发剂用量>反应时间。借助各仪器对接枝产物进行结构表征分析。红外光谱显示产物拥有各单体特征吸收峰,证明接枝反应的成功发生。从热分析曲线中可观察到,产物较玉米淀粉热分解温度有所升高,证明反应增大了其热稳定性。X-射线衍射曲线与扫描电镜照片显示,玉米淀粉的结构在反应期间遭到了破坏,使得其结晶结构消失。对三元接枝共聚产物的油田应用进行了初步考察,分别考察了其在水溶液与钻井液中的耐盐耐温性。在水溶液表观粘度测定中,发现各价态盐离子对表观粘度的影响变化规律相同,粘度下降程度不同。其中,高价态盐离子存在下的水溶液增粘性损失较多。同时测定高温下水溶液的表观粘度,发现在高温下该水溶液仍具有较好的增粘性。将该共聚产物添加于四种不同类型的钻井泥浆中,对各类钻井泥浆的流变性和降滤失效果进行测定。实验表明该产物在各类基浆钻井液中耐盐性能较好,而耐温性能较差。由此说明,该共聚产物在石油开采方面的应用性能还有待提高。更多还原

【Abstract】 As the demand for crude oil continues to rise in the world,protecting oil wells and improving oil recovery have become a hot topic in the world.As a natural macromolecule,starch has many advantage,the price is cheap,resource is very plenty,non-poisonous and degradable.The modified starch have been used in petroleum and natural gas industry for a long time because of their special structure,and now has been extensively studied.Firstly,the foreign samples were analyzed and tested to determine the main components.Secondly,the graft copolymers were synthesized by aqueous solution polymerization using corn starch,acrylamide and sodium acrylate in the condition of ammonium persulfate and anhydrous sodium bisulfite as composite initiators,which can be used for petroleum exploration.Different starch raw materials were screened,and the synthesis conditions such as the amount of Na AA,reaction time,reaction temperature and the amount of initiator added on the polymerization were discussed.The effects of the synthesis conditions were investigated from the results of apparent viscosity,monomer conversion and grafting ratio of the copolymer.The optimal reaction conditions were as follows: 0.3mol/L of the amount of Na AA,reaction time 3 h,reaction temperature 50℃,initiator dosage 3% of the total monomer mass.At the same time,the mathematical model was established by using the Box-Behnken central combination.According to the prediction model,the order of influence of each factor on apparent viscosity is: reaction temperature > initiator dosage > reaction time.The structure of the grafted product was analyzed by using each instrument.FTIR spectra showed that the product had characteristic peaks of each monomer,which proved the success of the grafting reaction.It can be observed from the TG analysis curve that the product has a higher thermal decomposition temperature than the corn starch,which proves that the reaction enhances its thermal stability.XRD curves and SEM photographs show that the structure of the corn starch was destroyed during the reaction,and the crystal structure was disappeared.The apparent viscosities of ternary graft copolymers in aqueous solution were measured in the presence of different salt ions.It was found that the effects of salt ions on apparent viscosity were the same,and the degree of viscosity decrease was different.Among them,in the presence of high valence salt ions,the loss of water solution viscosity is more.At the same time,the apparent viscosity of the aqueous solution at high temperature was determined,and it was found that the aqueous solution still had a good viscosity at high temperature.The copolymer product was added to four different types of drilling muds,and the rheology and filtration properties of the muds were measured.Experiments show that the product has better salt tolerance in drilling fluids of various types,but the temperature resistance is poor.Therefore,the application performance of the copolymer in petroleum exploitation needs to be improved.更多还原