碱对烷基苯磺酸盐吸附损失的影响研究

A Study on Adsorption of Heavy Alkyl Benzene Sulfonate on Reservoir Sand as Influenced by Alkali

研究了有效物含量50％的两种国产工业品重烷基苯磺酸盐HAILS在大庆洗油油砂上的吸附及外加碱的影响。实验温度45℃，HABS溶液用矿化度3．83g／L的模拟油藏盐水配制。随溶液浓度增大，HAILS样品1（M=427，CMC=0．86g／L）在0．5～1．0g／1，浓度区间显现吸附峰．最大吸附量1．29mg／g砂，在1．0～3．0g／L浓度区间吸附量缓慢下降。在外加碱影响实验中使用8．0g／LHAILS溶液。HABS样品1和样品2（M=440，CMC=0．78g／L）的吸附量，在外加NaOH浓度分别为6．0～11g／L和4．0～9．0g／L时低于无碱吸附量，最小吸附量分别为无碱吸附量的68％和53％，外加NaOH浓度≥12g／L时吸附量高而稳定。在外加Na2CO3浓度低于～3．0g／L或外加NaOH＋Na2CO3浓度低于-8．0g／L时，HABS样品2吸附量低于无碱吸附量，外加碱浓度再增大时则迅速升高。加入Na3PO4＋Na2CO3，加量≤12g／L时，HAILS样品2吸附量稳定而显著降低，其原因尚不明了。HABS样品1在储层岩心中的动态吸附量和在油砂上的吸附量随NaOH浓度的变化规律相同，岩心吸附量不到油砂吸附量的1／10。图4表5参8。

The adsorption and the influence of alkali on the adsorption of two commercial heavy alkyl benzene sulfonate, HABS, containing 50% active substances as EOR surfactant on oil-cleaned Daqing reservoir sand （RS） are studied at 45℃. HABS solution is prepared in a simulation formation brine of TSD = 3, 83 g/L. With increasing HABS solution concentration, the adsorption of HABS sample 1 （ M = 427, CMC = 0.86 g/L） on RS gces through a peak at concentration 0.5-1.0 g/L with a maximum of 1.29 mg/g sand and decreases slowly in concentration range 1.0-3.0 g/L. Various alkali, single and in combination, are introduced into 8.0 g/ L solution and it is found that： lowered values of HAKS adsorption on RS are observed for sample 1 and sample 2（M= 440, CMC = 0.78 g/L） in NaOH concentration range 6.0-11 and 4.0-9.0 g/L with minimal values being of 68% and 53% of that from coresponding alkaline free solution, respectively, and high and stable values of adsorption appear at NaOH concentration ≥12 g/L; the adsorption of HABS sample 2 on RS is lower than that from alkaline free solution when the Na2CO3 concentration 〈 --3.0 g/L or the NaOH ＋ Na2CO3 concentration 〈 -- 8.0 g/L and raises fast with further increasing concentration of these alkali; the adsorption of HABS sample 2 on RS decreases down notably and steadly when Na3PO4 ＋ Na2CO3 are introduced at dosage up to 12 g/L, the reasons for this phenomenon are unkown yet. The changes of adsorption of HABS sample 1 in reservoir core and on reservoir sand with increasing NaOH concentration are similar meanwhile the adsorption in core is by more than 10 times smaller than that on sand.