模拟内外源协同催化稠油水热裂解研究

Study on Aquathermolysis of Heavy Oil Catalyzed by Simulated Internal and External Sources

外源催化剂进入油藏后可能与原位无机矿物形成复合物,并发生协同催化水热裂解反应。制备了蒙脱土负载的柠檬酸锌复合物模拟内外源协同催化剂,考察了其对稠油的催化降黏性能,并对反应前后的稠油进行了热重(TGA)、差示扫描量热仪(DSC)、气相色谱(GC)和元素分析(EA)。结果表明,复合催化剂B@Zn(Ⅱ)L使稠油的降黏率(30℃)从55.2%升高到65.4%,说明稠油热采中存在内外源协同催化的现象;复合催化剂B@Zn(Ⅱ)L与供氢剂乙醇协同作用后,稠油的降黏率从65.4%升高到80.1%;协同作用后,稠油中的部分高烃类化合物裂解为低烃类化合物,部分重质组分分解为轻质组分。因此,稠油析蜡点降低,N、S质量分数下降,高碳烃类化合物相对含量降低,低碳烃相对含量增加。

In order to investigate the synergistic catalytic aquathermolysis after external catalyst entering the reservoir and complexation with in-situ inorganic minerals,a simulated internal and external synergistic catalyst of montmorillonite-supported zinc citrate complex was prepared,and its catalytic viscosity reduction performance for heavy oil was investigated.The heavy oil before and after the reaction was analyzed by thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),gas chromatography(GC)and elemental analysis(EA).The results showed that the composite catalyst B@Zn(Ⅱ)L increased the viscosity reduction rate of heavy oil from 55.2%to 65.4%at 30℃,which confirmed the phenomenon of internal and external source synergistic catalysis in heavy oil thermal recovery.After synergizing the composite catalyst B@Zn(Ⅱ)L with the hydrogen supply agent ethanol,the viscosity reduction rate of heavy oil increased from 65.4%to 80.1%.After the reaction of heavy oil,some of the high hydrocarbon compounds in the heavy oil were cracked into low hydrocarbon compounds after the reaction,and some heavy components were decomposed into light components.Therefore,the wax precipitation point of heavy oil decreased,the mass fraction of N and S decreased,the content of high hydrocarbons decreased,and the content of low carbon hydrocarbons increased.