For waterflooding reservoir,oil trapped in pore's dead ends is hardly flushed out,and usually becomes one typical type of residual oil.The microscopic displacement characteristics of polymer solution with varied v...For waterflooding reservoir,oil trapped in pore's dead ends is hardly flushed out,and usually becomes one typical type of residual oil.The microscopic displacement characteristics of polymer solution with varied viscoelastic property were studied by numerical and experimental method.According to main pore structure characteristics and rheological property of polymer solution through porous media,displacement models for residual oil trapped in dead ends were proposed,and upper-convected Maxwell rheological model was used as polymer solution's constitutive equation.The flow and stress field was given and displacement characteristic was quantified by introducing a parameter of micro swept coefficient.The calculated and experimental results show that micro swept coefficient rises with the increase of viscoelasticity;for greater viscoelasticity of polymer solution,vortices in the dead end have greater swept volume and displacing force on oil,and consequently entraining the swept oil in time.In addition,micro swept coefficient in dead end is function of the inclination angle(θ) between pore and dead end.The smaller of θ and 180-θ,the flow field of viscoelastic fluid is developed in dead ends more deeply,resulting in more contact with oil and larger swept coefficient.展开更多
针对稠油热采存在油汽比低、能耗大、CO_(2)排放高以及稠油冷采采出液难处理等问题,采用自制的降黏驱油剂ODA1配制驱替液,对其进行了静态降黏评价、性能分析以及特稠油冷采物理模拟实验研究。结果表明:提高驱替液中ODA1的质量分数和矿化...针对稠油热采存在油汽比低、能耗大、CO_(2)排放高以及稠油冷采采出液难处理等问题,采用自制的降黏驱油剂ODA1配制驱替液,对其进行了静态降黏评价、性能分析以及特稠油冷采物理模拟实验研究。结果表明:提高驱替液中ODA1的质量分数和矿化度,均能有效降低稠油黏度;当驱替液中ODA1质量分数为2%、矿化度为100 g/L时,特稠油与驱替液以质量比为0.5混合后的降黏率达到了70.62%;特稠油在驱替液表面自发扩散,油水自动分相,完全不乳化。在渗透率约为1 000×10^(-3)μm^(2)、地层温度为40℃、特稠油黏度为11 600 m Pa·s条件下进行模拟驱油实验,驱替液驱的采出程度较模拟地层水驱采出程度提高了6.31百分点;水驱后驱替液依次进行转驱、第1次闷井和第2次闷井,采出程度分别提高了7.48、11.70和7.83百分点,合计较水驱提高了27.02百分点,采出稠油在40℃条件下的黏度降至3 553 m Pa·s,降黏率达61.37%,驱替液具有边驱油边降黏的特点。同时在冷采过程中无碳排放,采出水无污染,可循环利用。研究成果为特稠油绿色冷采提供了一种新的技术思路。展开更多
针对现有商品泡沫驱油剂在高温高盐低渗透油藏中起泡量少、泡沫在多孔介质中稳定性差、驱油效率不高的实际问题,通过醚化、季铵化和取代反应,合成了两种非对称两性Gemini表面活性剂(PAHC和PAOC)作为CO_(2)泡沫驱的起泡剂,将合成的产物...针对现有商品泡沫驱油剂在高温高盐低渗透油藏中起泡量少、泡沫在多孔介质中稳定性差、驱油效率不高的实际问题,通过醚化、季铵化和取代反应,合成了两种非对称两性Gemini表面活性剂(PAHC和PAOC)作为CO_(2)泡沫驱的起泡剂,将合成的产物作为主起泡剂构建一种CO_(2)泡沫驱油体系,评价了该体系的界面活性、耐温耐剪切性、黏弹性、泡沫性能等,并进行了驱替实验。结果表明,PAHC和PAOC的临界胶束浓度c_(cmc)分别为6.76×10^(-5)和5.25×10^(-5)mol/L,对应的表面张力γ_(cmc)分别为31.56和30.71 m N/m。PAHC和PAOC的Krafft点分别低于0℃、1℃。在江苏油田采油二厂高21-3井组油藏温度为80℃、矿化度为7704 mg/L条件下,在恒定剪切速率170 s^(-1)时,0.4%PAHC(或PAOC)+0.1%水杨酸钠+0.1%姜磺素接枝马来酸酐共聚物的PAHC-C_(16)S、PAOC-C_(18)S泡沫体系,耐温分别为81℃和88℃,黏度分别可稳定在6.2和6.4 m Pa·s,具有良好的注入性和黏弹性。PAHC-C_(16)S、PAOC-C_(18)S泡沫体系分别可将油水界面张力降至2.37×10^(-2)和1.81×10^(-2)m N/m。PAOC-C_(18)S泡沫抗温性、抗盐性略好于PAHC-C_(16)S泡沫,能满足江苏油田采油二厂高21-3井组CO_(2)泡沫驱要求。岩心驱油实验结果显示,PAHC-C_(16)S和PAOC-C_(18)S起泡体系分别在CO_(2)驱基础上提高平均采收率20.12百分点和21.91百分点,可见两种起泡体系具有良好的应用前景。展开更多
基金Project(50574060) supported by the National Natural Science Foundation of ChinaProject(2005CB221300) supported by the National Basic Research Program of China
文摘For waterflooding reservoir,oil trapped in pore's dead ends is hardly flushed out,and usually becomes one typical type of residual oil.The microscopic displacement characteristics of polymer solution with varied viscoelastic property were studied by numerical and experimental method.According to main pore structure characteristics and rheological property of polymer solution through porous media,displacement models for residual oil trapped in dead ends were proposed,and upper-convected Maxwell rheological model was used as polymer solution's constitutive equation.The flow and stress field was given and displacement characteristic was quantified by introducing a parameter of micro swept coefficient.The calculated and experimental results show that micro swept coefficient rises with the increase of viscoelasticity;for greater viscoelasticity of polymer solution,vortices in the dead end have greater swept volume and displacing force on oil,and consequently entraining the swept oil in time.In addition,micro swept coefficient in dead end is function of the inclination angle(θ) between pore and dead end.The smaller of θ and 180-θ,the flow field of viscoelastic fluid is developed in dead ends more deeply,resulting in more contact with oil and larger swept coefficient.
文摘针对稠油热采存在油汽比低、能耗大、CO_(2)排放高以及稠油冷采采出液难处理等问题,采用自制的降黏驱油剂ODA1配制驱替液,对其进行了静态降黏评价、性能分析以及特稠油冷采物理模拟实验研究。结果表明:提高驱替液中ODA1的质量分数和矿化度,均能有效降低稠油黏度;当驱替液中ODA1质量分数为2%、矿化度为100 g/L时,特稠油与驱替液以质量比为0.5混合后的降黏率达到了70.62%;特稠油在驱替液表面自发扩散,油水自动分相,完全不乳化。在渗透率约为1 000×10^(-3)μm^(2)、地层温度为40℃、特稠油黏度为11 600 m Pa·s条件下进行模拟驱油实验,驱替液驱的采出程度较模拟地层水驱采出程度提高了6.31百分点;水驱后驱替液依次进行转驱、第1次闷井和第2次闷井,采出程度分别提高了7.48、11.70和7.83百分点,合计较水驱提高了27.02百分点,采出稠油在40℃条件下的黏度降至3 553 m Pa·s,降黏率达61.37%,驱替液具有边驱油边降黏的特点。同时在冷采过程中无碳排放,采出水无污染,可循环利用。研究成果为特稠油绿色冷采提供了一种新的技术思路。
文摘针对现有商品泡沫驱油剂在高温高盐低渗透油藏中起泡量少、泡沫在多孔介质中稳定性差、驱油效率不高的实际问题,通过醚化、季铵化和取代反应,合成了两种非对称两性Gemini表面活性剂(PAHC和PAOC)作为CO_(2)泡沫驱的起泡剂,将合成的产物作为主起泡剂构建一种CO_(2)泡沫驱油体系,评价了该体系的界面活性、耐温耐剪切性、黏弹性、泡沫性能等,并进行了驱替实验。结果表明,PAHC和PAOC的临界胶束浓度c_(cmc)分别为6.76×10^(-5)和5.25×10^(-5)mol/L,对应的表面张力γ_(cmc)分别为31.56和30.71 m N/m。PAHC和PAOC的Krafft点分别低于0℃、1℃。在江苏油田采油二厂高21-3井组油藏温度为80℃、矿化度为7704 mg/L条件下,在恒定剪切速率170 s^(-1)时,0.4%PAHC(或PAOC)+0.1%水杨酸钠+0.1%姜磺素接枝马来酸酐共聚物的PAHC-C_(16)S、PAOC-C_(18)S泡沫体系,耐温分别为81℃和88℃,黏度分别可稳定在6.2和6.4 m Pa·s,具有良好的注入性和黏弹性。PAHC-C_(16)S、PAOC-C_(18)S泡沫体系分别可将油水界面张力降至2.37×10^(-2)和1.81×10^(-2)m N/m。PAOC-C_(18)S泡沫抗温性、抗盐性略好于PAHC-C_(16)S泡沫,能满足江苏油田采油二厂高21-3井组CO_(2)泡沫驱要求。岩心驱油实验结果显示,PAHC-C_(16)S和PAOC-C_(18)S起泡体系分别在CO_(2)驱基础上提高平均采收率20.12百分点和21.91百分点,可见两种起泡体系具有良好的应用前景。
