烷基酚聚氧乙烯-聚氧丙烯醇醚用于稠油乳化降粘的研究

Studies on Reducing Viscosity of Extra-Heavy Crude Oil through O/W Emulsion Formation with Alkylphenoxypolyoxyethylenepolyoxypropylene

实验原油为胜利某油田高胶质(47.99%)高沥青质(9.13%)、凝点18℃的脱水脱气特稠油,3.4s-1下30℃粘度3.6×105mPa·s,50℃粘度1.6×104mPa·s,给出了粘温曲线。稠油乳化降粘实验条件如下:油水体积比7∶3,温度50℃,水相中烷基酚聚氧乙烯聚氧丙烯醇醚浓度5g/L。实验结果表明:作为稠油乳化降粘剂,该嵌段聚醚在烷基链长为C8～C18时均可使用,C8～C12时效果较好,C9的效果最好,形成的稠油乳状液粘度280mPa·s,稳定时间240min;壬基酚聚氧乙烯聚氧丙烯醇醚(EP EO PO)中EO加成数占EO+PO加成数的50%～95%时,乳状液粘度小于400mPa·s;用Davies法计算的HLB值在13～17时,使用4g/LEP EO PO形成的乳状液粘度小于300mPa·s;在水相中有2.0×104mg/LCa2++Mg2+存在时该乳化降粘剂可耐浓度≤2.0×105mg/L的NaCl;在有8.0×104NaCl和2.0×104mg/LCa2++Mg2+存在下,温度从35℃升高到80℃时,乳状液粘度和稳定时间均下降,90℃时乳状液发生反相,EP EO PO的使用温度为35～80℃。图4表3参4。

The crude oil used is a dehydrated and degased extraheavy oil from Shengli, which contains large amount of resin (47.99%) and asphaltene (9.13%), has pour point of 18℃ and viscosity at 3.4 s-1 of 3.6×105 mPa·s (30℃) and of 1.6×104 mPa·s (50℃). Its viscositytemperature relationship is illustrated. The experiments on viscosity reduction through O/W emulsion formation are conducted under following conditions: oil to water volume ratio 7∶3, temperature 50℃, and concentration of alkylphenoxypolyoxyethylenepolyoxypropylene in water phase 5 g/L. The experimental results show that: the alkylphenoxylated blockcopolyether can be used as emulsifier/viscosity reducer for the heavy crude when alkyl is C8-C18 ones, is more effective when alkyl is C8-C12 ones and is most effective with C9 alkyl while with the help of nonylphenoxylated blockcopolyether, EPEOPO, crude/water emulsion of viscosity 280 mPa·s is formed and keeps stable in 240 min; the emulsion viscosity is <400 mPa·s with EPEOPO in which the degree of polymerization (DP) of EO is in range 50-95% of the sum of DP of EO and PO; the viscosity of O/W emulsion formed with 4 g/L EPEOPO is <300 mPa·s when the HLB value of EPEOPO calculated by Davies method is in range 13-17; EPEOPO is tolerant to NaCl up to 2.0×105 mg/L when the water phase contains 2.0×104 mg/L Ca2++Mg2+; at the presence of 8.0×104 mg/L NaCl and 2.0×104 mg/L Ca2++Mg2+ in water phase, the viscosity and life of the O/W emulsion formed decrease when temperature raises from 35℃ to 80℃ and phase conversion takes place at 90℃, the working temperature of nonylphenoxypolyoxyethylenepolyoxypropylene EPEOPO is in range 35-80℃.