Hoffmann Eugen, Hincapie Rafael E, Borovina Ante, Clemens Torsten, Tahir Muhammad, Lueftenegger Markus, Wegner Jonas
HOT Microfluidics GmbH, 38640 Goslar, Germany.
OMV Exploration and Production GmbH, 1020 Vienna, Austria.
Polymers (Basel). 2024 Mar 20;16(6):854. doi: 10.3390/polym16060854.
The study demonstrates the significant enhancement in oil production from a Romanian oil field using alkali-polymer (AP) flooding for reactive viscous oil. We conducted comprehensive interfacial tension (IFT) measurements across various alkali and AP concentrations, along with phase behavior assessments. Micromodel flooding experiments were used to examine pore-scale effects and select appropriate chemical concentrations. We tested displacement efficiency at the core level and experimented with different sequences and concentrations of alkali and polymers to minimize costs while maximizing the additional recovery of reactive viscous oil. The IFT analysis revealed that saponification at the oil-alkali interface significantly lowers IFT, but IFT gradually increases as soap diffuses away from the interface. Micromodels indicated that polymer or alkali injection alone achieve only minimal incremental recovery beyond waterflooding. However, AP flooding significantly enhanced incremental oil recovery by efficiently moving the mobilized oil with the viscous fluid and increasing exposure of more oil to the alkali solution. Coreflood experiments corroborated these findings. We also explored how divalent cations influence polymer concentration selection, finding that softening the injection brine significantly increased the viscosity of the AP slug.
该研究表明，在罗马尼亚的一个油田中，使用碱-聚合物（AP）驱替法开采活性稠油可显著提高原油产量。我们针对不同的碱浓度和AP浓度进行了全面的界面张力（IFT）测量，并进行了相行为评估。利用微观模型驱替实验来研究孔隙尺度效应并选择合适的化学剂浓度。我们在岩心层面测试了驱替效率，并试验了不同的碱和聚合物注入顺序及浓度，以在使活性稠油的额外采收率最大化的同时将成本降至最低。IFT分析表明，油-碱界面处的皂化作用显著降低了IFT，但随着皂从界面扩散开来，IFT会逐渐增加。微观模型显示，单独注入聚合物或碱，在水驱基础上只能实现极小的采收率增量。然而，AP驱替通过有效地将可动油与粘性流体一起驱替，并增加更多原油与碱溶液的接触，显著提高了采收率增量。岩心驱替实验证实了这些发现。我们还探究了二价阳离子如何影响聚合物浓度的选择，发现软化注入盐水会显著提高AP段塞的粘度。
