Experimental study on foamy viscosity by analysing CO2 micro-bubbles in hexadecane
Experimental study on foamy viscosity by analysing CO2 micro-bubbles in hexadecane
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DOI：
10.11648/j.ogce.20140202.11
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Chanmoly Or;K. Sasaki;Y. Sugai;M. Nakano;Motonao Imai
中科院分区：
文献类型：
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作者：
Chanmoly Or;K. Sasaki;Y. Sugai;M. Nakano;Motonao Imai
稠油中的气体不断解吸，产生较低的粘度并分散气体微泡。本研究通过实验室实验测量了稠油典型成分泡沫状十六烷的粘度，并研究了温度20~50℃、减压压力1.0~6.0MPa下的CO2气体微泡。显然，十六烷的流动性随着泡沫膨胀的增加而增加。泡沫与原始十六烷的粘度比显示为 0.90 - 0.70，泡沫溶胀在 3.0 - 4.8% 的溶胀范围内增加。泡沫溶胀是由分散的气体微泡引起的，根据目前的测量结果，其粘度在低温或高泡沫溶胀下更容易降低。气泡分布显示，在测量后 3 分钟内，大气泡（直径约 50 µm）聚结，但微气泡（直径约 5 µm）在 1575 s-1 的剪切力下保持稳定。这表明直径较小的微气泡对高剪切速率具有更高的稳定性。因此，通过产生CO2微气泡产生泡沫能够使流体通过孔喉并降低粘度，并通过其膨胀来提高聚集体和细孔等非流动域的采收率。
Continuous desorbing gas in the heavy oil generates lower viscosity with dispersing gas micro-bubbles. In this study, laboratory experiments were carried out to measure the viscosity of foamy hexadecane, typical component of heavy oil, and to investigate the CO2 gas micro-bubbles at ranged temperature of 20 – 50 °C and depressurization pressure of 1.0 – 6.0 MPa. Apparently, hexadecane mobility increases with increasing foam swelling. The viscosity ratio of foam vs. original hexadecane showed 0.90 – 0.70 with increasing foam swelling in the swelling range of 3.0 – 4.8%. The foam swelling is caused by dispersed gas micro-bubbles, and its viscosity was more reducible at either low temperature or high foam swelling based on present measurement results. The bubble distribution showed the large bubbles (approximately 50 µm in diameter) were coalesced but the micro-bubbles (approximately 5 µm in diameter) were stable under the shear of 1575 s-1, within 3 minutes of measuring. It shows that the micro-bubbles in smaller diameter have higher stability against the high shear rate. Therefore, generating foam by creating CO2 micro-bubbles is capable to make flow through the pore throats with viscosity reduction and improves oil recovery from non-mobile domain, such as aggregate and fine pores, by its swelling.