共存物及其投加方式对Tween 80 在中砂上吸附损失的影响

通过静态吸附实验,研究了25℃条件下,表面活性剂冲洗液Tween 80在中砂上的吸附,以及CaCl2、SDS和木质素磺酸盐(木质素磺酸钠和木质素磺酸铵)对其吸附量的影响.结果表明,向Tween 80溶液中加入CaCl2和SDS都可以显著增加其吸附量.投加量越多,吸附量越大,当投加量达到一定程度后,吸附达到饱和,不会继续增大.SDS以预吸附的方式注入同样会导致Tween 80吸附量升高.而木质素磺酸盐与Tween 80共混则可大大降低Tween 80的吸附量.随着投加量的增加,Tween 80吸附量明显下降.在低投加比例(1:10)时,木质索磺酸铵效果较好,可以减少20%-75%的吸附量.而木质素磺酸钠只能减少10%-60%.当投加较高比例(1:2)时,两者都口1以明显降低Tween 80的吸附量,可达70%-90%.而采用木质素磺酸盐预吸附的方式注入的效果较混合注入要好,相同投加最的情况下,所降低Tween 80的吸附量是混合注入时的1.2-1.8倍.因此.在表面活性剂原位冲洗过程中用木质素磺酸盐进行预冲洗,能够减少表面活性剂吸附量,降低冲洗成本,可以作为原位冲洗过程中降低吸附损失的一种手段.

Effect of Concomitant Substances and Addition Order on the Adsorption of Tween80 on Sand

Adsorption of Tween 80 on sand was investigated, and the effect of inorganic salts (CaCl2), anionic surfactant (SDS) and lignosulphonates (sodium lignosulphonate or ammonium lignosulphonate) on the adsorption of Tween 80 on sand were evaluated at 25 degrees C. The results show that saturated adsorption amount of Tween 80 on sand enhance when CaCl2 or SDS is added into flushing solution of Tween 80. And the adsorption of Tween 80 on sand increase with the increase of molar fraction of CaCl2 or SDS in mixed flushing solution. And adsorption amount of Tween 80 on sand also enhance when SDS is added into sand firstly. The effects of mixing ratios and addition order of lignosulphonates on adsorption of Tween 80 were considered. The results show that with the increase of molar fraction of lignosulphonates in mixing flushing solution, adsorption amount of Tween 80 on sand decrease. The adsorption amount of Tween 80 reduce 20%-75% due to the exist of ammonium lignosulphonate is superior to sodium lignosulphonate (10%-60%) when mix the lignosulphonates-Tween 80 at the total mass ratios of 1:10, while the adsorption amount of Tween 80 reduce 70%-90% at the total mass ratios of 1:2. Lignosulphonates added into sand firstly is more efficient than that together. Therefore,use of lignosulphonates as a preflush can reduce the adsorption of surfactants on sand and is a better method to applied in in situ flushing.