深圳大学学报理工版

泡沫驱油体系在多孔介质中的渗流机理十分复杂,为准确认识CO2泡沫驱油机理,揭示其渗流规律.本研究基于低渗透油藏CO2泡沫驱渗流特征,考虑启动压力梯度及泡沫中表面活性剂的吸附,根据分流理论和物质平衡原理,将表面活性剂分别溶于水或CO2,并在不同注入条件下,分别建立低渗透油藏CO2泡沫驱一维渗流模拟模型.运用图解法进行求解,确定驱替过程中含水饱和度的剖面分布.油藏数值模拟结果验证了所建模型的有效性.对不同泡沫质量、表面活性剂分布情况下的曲线进行分析,结果表明,泡沫中含水率提高,泡沫质量变差,泡沫驱替前缘移动速度先增后减,存在最佳的含水饱和度使得驱替效果最好; 泡沫混相驱替前缘移动速度随气相与液相中表面活性剂质量浓度之比的增大而增加,当其趋近于无限大时,驱替效果达到最优.

The seepage mechanism of foam flow in porous media is very complicated. The purpose of this research is explaining the flooding mechanism accurately and revealing the seepage mechanism of CO2 foam flow in porous media.Based on the characteristics of CO2 foam flow in low permeability oil reservoirs, a novel model of CO2 foam flooding considering the effects of surfactant adsorption and threshold pressure gradient is established and solved using the fractional-flow function and the principle of material balance. We derive the fractional-flow solutions for the foam displacement to find the water-saturation distribution in system, in the two cases of surfactant dissolved in supercritical CO2 or in water, respectively. The numerical simulations are presented to verify the graphical solutions obtained from fractional-flow function. In addition, the controlling factors that control the mobility and moving velocity of the foam bank are investigated, and the optimal design of flooding process is proposed(in the context of idealized 1D displacements). As the water fraction of the injected foam increases with deterioration of foam quality, the velocity of the flooding front would first increase and then decrease. Therefore, the optimal water fraction can be expected to maintain the gas front slightly ahead of the foam front for best performance. The propagation of the foam front depends on both surfactant adsorption onto rock and the partitioning of surfactant between water and CO2. The optimal process can be reached while the ratio of surfactant concentrations dissolved in CO2 to that in water tends to zero. Our work can provide a theoretical basis for the design of CO2 foam process in field applications.

引言
1 低渗透油藏CO₂泡沫驱模型
2 模型求解与验证
3 饱和度剖面分布特征分析
4 结论

图1 CO2泡沫驱油示意图<br/>Fig.1 Schematic of CO2 foam flooding

图1 CO2泡沫驱油示意图
Fig.1 Schematic of CO2 foam flooding

图2 表面活性剂溶于水的情形<br/>Fig.2 Condition of surfactant dissolved in water

图2 表面活性剂溶于水的情形
Fig.2 Condition of surfactant dissolved in water

图3 表面活性剂溶于CO2的情形<br/>Fig.3 Condition of surfactant dissolved in CO2

图3 表面活性剂溶于CO2的情形
Fig.3 Condition of surfactant dissolved in CO2

图4 第2个气-水两相区消失的情形<br/>Fig.4 Condition of disappearance of the second gas bank

图4 第2个气-水两相区消失的情形
Fig.4 Condition of disappearance of the second gas bank

图5 气-水两相区全部消失的情形<br/>Fig.5 Condition of disappearance of gas banks

图5 气-水两相区全部消失的情形
Fig.5 Condition of disappearance of gas banks

图6 气体前缘低于泡沫前缘速度的情形<br/>Fig.6 Condition that miscible shock velocity is slower than that of chemical shock

图6 气体前缘低于泡沫前缘速度的情形
Fig.6 Condition that miscible shock velocity is slower than that of chemical shock

图7 表面活性剂的质量浓度满足ρsg/ρsw>5.5的情形<br/>Fig.7 The results with ρsg/ρsw>5.5

图7 表面活性剂的质量浓度满足ρsg/ρsw>5.5的情形
Fig.7 The results with ρsg/ρsw>5.5

图8 表面活性剂分配满足ρsg/ρsw→∞的情形<br/>Fig.8 The results with ρsg/ρsg//sub>→∞

图8 表面活性剂分配满足ρsg/ρsw→∞的情形
Fig.8 The results with ρsg/ρsg//sub>→∞

[1] 杜庆军,侯健,鹿腾,等.基于分流方程的泡沫体系渗流特征[J].东北石油大学学报,2010, 34(4):71-76.
[2] 王冠华.超临界CO2泡沫调驱技术研究[D].东营:中国石油大学(华东),2011.

₂

[3] 李冉. 低张力泡沫驱室内实验与数值模拟研究[D]. 东营:中国石油大学(华东),2013.
[4] 鹿腾,李兆敏,李敬,等.基于泡沫微观渗流特征的泡沫驱数学模型[J].计算物理,2012,29(4):519-524.
[5] 徐庆岩, 杨正明, 何英,等. 超低渗透油藏非线性渗流数值模拟[J].深圳大学学报理工版, 2012, 29(6):94- 98.
[6] 刘露,李华斌,吴灿,等.空气泡沫在孔隙介质中的渗流特征研究[J].油田化学,2015(1): 78-82.
[7] 杜东兴,王德玺,贾宁洪,等.多孔介质内CO2泡沫液渗流特性实验研究[J].石油勘探与开发, 2016,43(3):456- 461.

₂

[8] 刘祖鹏, 李兆敏. CO2 驱油泡沫防气窜技术实验研究[J]. 西南石油大学学报自然科学版, 2015, 37(5): 117-122.

₂

[9] 吕春阳,赵凤兰,侯吉瑞,等.泡沫驱前调剖提高采收率室内实验[J].油气地质与采收率,2015,22(5):69-73.
[10] MANCEAU J C, MA J, LI R,et al. Two-phase flow properties of a sandstone rock for the CO2/water system: core-flooding experiments, and focus on impacts of mineralogical changes[J]. Water Resources Research,2015,51(4):2885-2900.
[11] MA Kun, FARAJZADEH R, LOPEZ-SALINAS J L,et al. Non-uniqueness, numerical artifacts, and parameter sensitivity in simulating steady-state and transient foam flow through porous media[J]. Transport in Porous Media,2014,102(3):325-348.
[12] LEE S, LEE G, KAM S I. Three-phase fractional flow analysis for foam-assisted non-aqueous phase liquid(NAPL)remediation[J]. Transport in Porous Media, 2014, 101(3): 373- 400.
[13] ZHANG Yang, WANG Yuting, XUE Fangfang, et al. CO2 foam flooding for improved oil recovery: Reservoir simulation models and influencing factors[J]. Journal of Petroleum Science and Engineering,2015,133:838-850.
[14] ROSSEN W R, BOEIJE C S. Fitting foam-simulation-model parameters to data: II. surfactant-alternating-gas foam applications[J]. SPE Reservoir Evaluation & Engineering, 2015,18(2):273-283.
[15] LEE S. Modeling of foam flow in porous media for subsurface environmental remediation[D]. Austin: the University of Texas at Austin, 2014.
[16] ROOSTAPOUR A, KAM S I. Anomalous foam-fractional-flow solutions at high-injection foam quality[J]. SPE Reservoir Evaluation & Engineering,2013,16(1):40-50.
[17] LIU Jie, CHENG Ruihui, ZHANG Zhen, et al. Numerical simulation of N2 foam flooding in medium-permeability light-oil reservoir with ultra-high water cut[J]. Chemistry and Technology of Fuels and Oils, 2017, 53(2): 286-295.
[18] XING Dazun, WEI Bing, MCLENDON W J, et al. CO2-soluble, nonionic, water-soluble surfactants that stabilize CO2-in-brine foams[J]. SPE Journal, 2012, 17(4): 1172-1185.
[19] ZANGANEH M N, KAM S I, LAFORCE T C,et al.The method of characteristics applied to oil displacement by foam[J]. SPE Journal,2011,16(1):8-23.
[20] TELMADARREIE A, TRIVEDI J J. New insight on carbonate-heavy-oil recovery: pore-scale mechanisms of post-solvent carbon dioxide foam/polymer-enhanced-foam flooding[J]. SPE Journal, 2016, 21(5): 1655-1668.
[21] IRAWAN S, PERMATASARI K A, BAYUAJI R. Effect of density and resistivity measurement for foam flooding propagation in static condition[C]// IOP Conference Series: Materials Science and Engineering.[S. l.]: IOP Publishing, 2017, 267(1): 012031.
[22] Keliang W, Yuhao C, Gang W, et al. The Evaluation of Foam Performance and Flooding Efficiency[C]// IOP Conference Series: Earth and Environmental Science. IOP Publishing, 2017, 100(1): 012211.
[23] 赵金省, 李天太, 张明,等. 聚合物驱后氮气泡沫驱油特性及效果[J]. 深圳大学学报理工版, 2010, 27(3):361-366.
[24] ZHOU Z, ROSSEN W R. Applying fractional-flow theory to foam processes at the "limiting capillary pressure"[J]. SPE Advanced Technology Series, 1995, 3(1): 154-162.
[25] MAYBERRY D J, KAM S I. The use of fractional-flow theory for foam displacement in presence of oil[J]. SPE Reservoir Evaluation & Engineering, 2008, 11(4): 707-718.
[26] KHOSHNEVIS N, MAHANI H, REHLING J, et al. Investigation of pressure transient behaviour during injection fall-off(IFO)test in foam flooding[J]. Journal of Petroleum Science and Engineering, 2016, 149(4):860-872.
[27] CHENG L, REME A B, SHAN D, et al. Simulating foam processes at high and low foam qualities[C]// SPE/DOE improved oil recovery symposium. Tulsa, USA:Society of Petroleum Engineers, 2000:SPE-59287-MS.
[28] XU X, SAEEDI A, LIU Keyu. Experimental study on a novel foaming formula for CO2 foam flooding[J]. Journal of Energy Resources Technology-Transactions of the ASME,2017,139(2):022902.

备注

引言

1 低渗透油藏CO₂泡沫驱模型

2 模型求解与验证

3 饱和度剖面分布特征分析

4 结论

期刊信息

备注

引言

1 低渗透油藏CO2泡沫驱模型

2 模型求解与验证

3 饱和度剖面分布特征分析

4 结 论

期刊信息

1 低渗透油藏CO₂泡沫驱模型

4 结论