表(biao)(biao)面(mian)(mian)活(huo)性(xing)(xing)(xing)劑是一(yi)類在(zai)較低(di)濃度時能顯著降低(di)表(biao)(biao)面(mian)(mian)活(huo)性(xing)(xing)(xing)的(de)物(wu)質(zhi)(zhi),由于其分(fen)子結(jie)構中同(tong)(tong)時含(han)有親(qin)水(shui)基和疏水(shui)基,具(ju)有與其他化(hua)合(he)物(wu)不同(tong)(tong)的(de)獨特的(de)雙親(qin)性(xing)(xing)(xing)質(zhi)(zhi),這些性(xing)(xing)(xing)質(zhi)(zhi)可使表(biao)(biao)面(mian)(mian)活(huo)性(xing)(xing)(xing)劑在(zai)溶液中形(xing)成分(fen)子有序組合(he)體,也(ye)可以在(zai)界面(mian)(mian)吸附從而改變界面(mian)(mian)張力和表(biao)(biao)面(mian)(mian)潤(run)濕性(xing)(xing)(xing)能等。

在大慶油(you)(you)田(tian)三次采油(you)(you)中(zhong),表(biao)面活(huo)性劑作(zuo)為(wei)添加劑的(de)(de)(de)(de)(de)主要(yao)成分(fen)起到(dao)重(zhong)要(yao)的(de)(de)(de)(de)(de)驅(qu)(qu)油(you)(you)作(zuo)用。為(wei)了(le)適應當前的(de)(de)(de)(de)(de)采油(you)(you)狀況(kuang),提高石(shi)油(you)(you)采收率,改變石(shi)油(you)(you)的(de)(de)(de)(de)(de)供(gong)需(xu)矛盾,有(you)關表(biao)面活(huo)性劑在油(you)(you)水界(jie)面的(de)(de)(de)(de)(de)行(xing)為(wei)和(he)(he)抗鹽性能的(de)(de)(de)(de)(de)研究(jiu)一直備受關注。本文(wen)采用分(fen)子(zi)動力學模擬的(de)(de)(de)(de)(de)方(fang)法,從(cong)微(wei)觀角度對表(biao)面活(huo)性劑在油(you)(you)/水界(jie)面的(de)(de)(de)(de)(de)聚集形態、吸附情況(kuang)和(he)(he)相互(hu)作(zuo)用機理等方(fang)面開展了(le)系統的(de)(de)(de)(de)(de)理論研究(jiu)工作(zuo),對選取的(de)(de)(de)(de)(de)四(si)種(zhong)類型(xing)的(de)(de)(de)(de)(de)驅(qu)(qu)油(you)(you)用表(biao)面活(huo)性劑進(jin)行(xing)了(le)對比分(fen)析,對研究(jiu)結果給(gei)出了(le)合(he)理的(de)(de)(de)(de)(de)解釋。

理(li)論(lun)研究(jiu)結果(guo)對(dui)于進一步指導驅(qu)油(you)(you)用表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)的篩選和(he)(he)(he)高效驅(qu)油(you)(you)用表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)的分(fen)(fen)(fen)子(zi)(zi)設計(ji)(ji)具有(you)重(zhong)要(yao)的理(li)論(lun)意義和(he)(he)(he)實際(ji)應用價值。本論(lun)文(wen)首(shou)先通過分(fen)(fen)(fen)子(zi)(zi)動(dong)力學模擬(ni)方法研究(jiu)了(le)(le)(le)陰離(li)子(zi)(zi)、非離(li)子(zi)(zi)、兩性(xing)(xing)(xing)離(li)子(zi)(zi)和(he)(he)(he)雙子(zi)(zi)四(si)種(zhong)類型(xing)表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)在(zai)油(you)(you)/水(shui)(shui)界面(mian)(mian)(mian)(mian)(mian)的微(wei)觀行為,計(ji)(ji)算了(le)(le)(le)四(si)種(zhong)表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)在(zai)油(you)(you)/水(shui)(shui)界面(mian)(mian)(mian)(mian)(mian)形(xing)成的界面(mian)(mian)(mian)(mian)(mian)張力、界面(mian)(mian)(mian)(mian)(mian)厚度和(he)(he)(he)界面(mian)(mian)(mian)(mian)(mian)形(xing)成能,計(ji)(ji)算了(le)(le)(le)四(si)種(zhong)表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)親水(shui)(shui)基與(yu)水(shui)(shui)分(fen)(fen)(fen)子(zi)(zi)的徑向分(fen)(fen)(fen)布函數,計(ji)(ji)算了(le)(le)(le)不同電場強度對(dui)表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)體系中水(shui)(shui)擴散系數的影響(xiang),從(cong)微(wei)觀角度揭示了(le)(le)(le)驅(qu)油(you)(you)用表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)(mian)活(huo)(huo)(huo)性(xing)(xing)(xing)劑(ji)(ji)(ji)(ji)的驅(qu)油(you)(you)機理(li)。

其(qi)次比較了(le)(le)不(bu)同(tong)陽(yang)離(li)(li)(li)子(Na~+、Mg~(2+)和Ca~(2+))與四(si)種不(bu)同(tong)類(lei)型驅油(you)(you)用表面(mian)活(huo)(huo)(huo)性(xing)(xing)劑(ji)頭(tou)基(ji)之間(jian)的相互作用情況,通過平均力(li)勢(PMF)分析了(le)(le)陽(yang)離(li)(li)(li)子與表面(mian)活(huo)(huo)(huo)性(xing)(xing)劑(ji)頭(tou)基(ji)之間(jian)形成的結合能(neng)(neng)和解離(li)(li)(li)能(neng)(neng),對表面(mian)活(huo)(huo)(huo)性(xing)(xing)劑(ji)抗鹽性(xing)(xing)能(neng)(neng)進(jin)行了(le)(le)評價,建議了(le)(le)驅油(you)(you)用表面(mian)活(huo)(huo)(huo)性(xing)(xing)抗鹽作用機理。最后(hou)通過自由(you)能(neng)(neng)微擾計算了(le)(le)四(si)種不(bu)同(tong)類(lei)型表面(mian)活(huo)(huo)(huo)性(xing)(xing)劑(ji)在(zai)水溶(rong)液中的熱(re)力(li)學參數(shu),比較了(le)(le)四(si)種驅油(you)(you)用表面(mian)活(huo)(huo)(huo)性(xing)(xing)劑(ji)膠(jiao)束形成的能(neng)(neng)力(li)。

研究結(jie)果表(biao)(biao)明,油(you)/表(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)劑(ji)/水(shui)(shui)界(jie)面(mian)(mian)(mian)張力(li)(li)低有利于驅(qu)油(you),界(jie)面(mian)(mian)(mian)厚(hou)度(du)大、界(jie)面(mian)(mian)(mian)形(xing)成能(neng)低有利于降(jiang)(jiang)低界(jie)面(mian)(mian)(mian)張力(li)(li)。隨著界(jie)面(mian)(mian)(mian)張力(li)(li)的(de)(de)(de)(de)(de)降(jiang)(jiang)低,表(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)劑(ji)在油(you)/水(shui)(shui)界(jie)面(mian)(mian)(mian)穩定性(xing)(xing)增(zeng)強。四種(zhong)驅(qu)油(you)用表(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)劑(ji)中雙子(zi)表(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)劑(ji)降(jiang)(jiang)低油(you)/水(shui)(shui)界(jie)面(mian)(mian)(mian)張力(li)(li)的(de)(de)(de)(de)(de)能(neng)力(li)(li)最(zui)強,形(xing)成的(de)(de)(de)(de)(de)結(jie)構(gou)最(zui)為穩定,更適合(he)(he)(he)作為驅(qu)油(you)用表(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)劑(ji)。表(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)劑(ji)頭基與水(shui)(shui)分(fen)子(zi)之間存在著化學(xue)水(shui)(shui)合(he)(he)(he)層和(he)(he)物(wu)理水(shui)(shui)合(he)(he)(he)層,對于不同(tong)陽離子(zi)(Na~+、Mg~(2+)和(he)(he)Ca~(2+))參與的(de)(de)(de)(de)(de)驅(qu)油(you)過程,徑向分(fen)布函數(shu)的(de)(de)(de)(de)(de)峰值(zhi)越高,表(biao)(biao)面(mian)(mian)(mian)活(huo)(huo)性(xing)(xing)劑(ji)頭基與陽離子(zi)之間的(de)(de)(de)(de)(de)作用力(li)(li)越強,三種(zhong)陽離子(zi)對水(shui)(shui)合(he)(he)(he)層的(de)(de)(de)(de)(de)影響依次為Mg~(2+)Ca~(2+)Na~+。

三(san)種(zhong)不同(tong)陽離(li)子(zi)(zi)(zi)與四(si)種(zhong)表(biao)面(mian)(mian)活(huo)性(xing)(xing)劑(ji)結(jie)(jie)合能的(de)(de)結(jie)(jie)果(guo)顯示,兩性(xing)(xing)和非離(li)子(zi)(zi)(zi)表(biao)面(mian)(mian)活(huo)性(xing)(xing)劑(ji)的(de)(de)抗鹽(yan)(yan)性(xing)(xing)能高(gao)于陰離(li)子(zi)(zi)(zi)和雙子(zi)(zi)(zi)表(biao)面(mian)(mian)活(huo)性(xing)(xing)劑(ji),而解(jie)離(li)能的(de)(de)結(jie)(jie)果(guo)顯示,非離(li)子(zi)(zi)(zi)較兩性(xing)(xing)表(biao)面(mian)(mian)活(huo)性(xing)(xing)劑(ji)在(zai)高(gao)鹽(yan)(yan)狀(zhuang)態下更(geng)容易失去活(huo)性(xing)(xing),因而,在(zai)高(gao)鹽(yan)(yan)油藏(zang)條件下,兩性(xing)(xing)表(biao)面(mian)(mian)活(huo)性(xing)(xing)劑(ji)更(geng)適(shi)用于驅油用。計算的(de)(de)熱力學數據(ju)表(biao)明,四(si)種(zhong)表(biao)面(mian)(mian)活(huo)性(xing)(xing)劑(ji)在(zai)水溶(rong)液中可自發(fa)形成(cheng)膠束,膠束化過(guo)程主要是熵(shang)驅動,隨著溫(wen)度的(de)(de)升高(gao),熵(shang)驅動的(de)(de)貢獻逐步減小,而焓(han)驅動的(de)(de)貢獻逐步增大,存在(zai)著明顯的(de)(de)線性(xing)(xing)焓(han)-熵(shang)補償現象。

四種表(biao)面活(huo)性劑的(de)吉(ji)布斯自由能數據表(biao)明,兩性和雙(shuang)子表(biao)面活(huo)性劑形成膠束(shu)化(hua)的(de)能力較強,穩(wen)定性好,有(you)較好的(de)驅油(you)效果。