矿化水对稠油乳化降粘剂SDGD降粘效果的影响

The Functions of Emulsificator/Viscosity-Reducer SDGD for Viscous Crude Oil as Influenced by Water Salinity

SDGD是室内研制的阴离子、两性表面活性剂和助剂的复配物。考察了SDGD对孤东稠油的乳化降粘作用并与碱 (NaOH)水作了对比。在 5 0℃、油水质量比为 7∶3条件下 ,0 .5g/dLSDGD蒸馏水溶液与稠油形成的乳状液粘度仅为 32mPa·s ,相同浓度的SDGD在矿化度 10 0 0 0mg/L、含Ca2 + +Mg2 + 15 0mg/L的矿化水中的溶液与稠油形成的乳状液粘度略高于 6 0mPa·s,对稠油 (90 0 0mPa·s)的乳化降粘率均在 99%以上 ,乳状液不稳定 ,易破乳。矿化度维持 10 0 0 0mg/L不变 ,SDGD可以抗耐的Ca2 + +Mg2 + 浓度为 2 5 0mg/L。粘土样在 5 g/dLSDGD水溶液中的膨胀程度小于在相同浓度KCl水溶液中的膨胀程度。因此 ,SDGD可用于高矿化度稠油油藏的乳化降粘开采。碱水作为稠油乳化降粘剂 ,在高矿化度特别是高钙镁离子浓度条件下效果很差。讨论了SDGD和NaOH在稠油乳化降粘中的有关机理。

The emulsifying/viscosity reducing functions for viscous crude oil from Gudong, Shengli, of a combination of anionic and amphoteric surfactants and auxiliaries denoted as SDGD are investigated in comparision with aqueous alkaline NaOH. At 50℃ and mass ratio of oil to aqueous phases 7∶3, 0.5 g/dL SDGD solution in distilled water and the crude form O/W emulsion of viscosity 32 mPa·s, 0.5 g/dL SDGD solution in salt water of TSD = 10 000 mg/L and Ca 2+ +Mg 2+ 150 mg/L and the crude form O/W emulsion of viscosity slightly higher than 60 mPa·s. In both cases the reduction in viscosity by emulsification of the crude (9 000 mPa·s) is >99% and the emulsions created are not stable and easy to breakdown. SDGD is tolerent to 250 mg/L Ca 2+ +Mg 2+ at TSD =10 000 mg/L. The swelling rate of clay samples in 5 g/dL SDGD aqueous solution is less than that in KCl solution of same concentration. SGDG can be used as emulsificator/viscosity reducer for recovery of viscous crude oil from high salinity reservoirs. Aqueous alkaline is much less effective when applied as emulsificator/viscosity reducer to reservoirs of high salinity and high Ca 2+ +Mg 2+ . The mechanisms involved in emulsifying and reduction in viscosity of viscous crude oils by SDGD and aqueous alkaline are discussed.