水驱油藏中原油极性物质对吸附和润湿性影响的分子模拟

doi:10.19596/j.cnki.1001-246x.8316

摘要/Abstract

摘要：

为了研究水驱油藏中原油极性物质的吸附机理及其对油藏表面润湿性的影响，构建以石英为代表的砂岩岩石骨架模型，己烷为代表的非极性物质模型和以甲苯、胶质和沥青质为代表的极性物质模型，运用分子模拟方法研究4种原油组分和水分子在砂岩油藏表面竞争吸附过程和润湿状态。结果表明：水与4种原油组分在石英矿物表面竞争吸附时，原油中的非极性物质会比极性物质更加容易脱附。极性物质会随着时间的变化逐渐吸附在矿物表面，非极性的物质会随着时间变化逐渐远离矿物表面。吸附过程中静电力起吸附作用，范德华力起排斥作用。最后结合润湿性实验结果，从机理上解释了不同原油组成对润湿性的影响，即原油组分中极性物质含量越高，胶质沥青质含量越大，岩石表面油湿性越大，且水驱过程中润湿性向亲水方向变化越难。结论对提升水驱油藏采收率影响因素的认识有重要意义。

关键词: 极性物质, 竞争吸附, 润湿性, 分子模拟

Abstract:

To study adsorption mechanism of polar substance of crude oil in water flooding reservoir and its influence on surface wettability of reservoir, a sandstone skeleton model represented by quartz, a non-polar substance model represented by hexane and polar substance models represented by toluene, resin and asphaltene are constructed. Competition adsorption process and wet condition of four crude oil components and water molecules on sandstone reservoir surface are studied with molecular simulation. It shows that non-polar substances of crude oil are more easily desorbed than the polar substances when water competes with the four components for adsorption on quartz mineral surface. And as time goes by, polar substances are gradually adsorbed on the rock mineral surface, while non-polar substances move away gradually. Electrostatic force acts as adsorption and van der Waals force acts as repulsion in adsorption process. Finally, based on wettability experiment results, influence of different crude oil compositions on wettability was explained in mechanism, that is, the more polar substance in the oil component, the more resin and asphaltene, the strong the oil wettability of rock surface is. And it is more difficult to change the wettability to hydrophilic during water flooding. The conclusions are of great significance in the understanding of contributing factors of the recovery in water flooding reservoirs.

Key words: polar substance, competitive adsorption, wettability, molecular simulation

中图分类号:

TE312

曹仁义, 黄涛, 程林松, 高占武, 贾志豪. 水驱油藏中原油极性物质对吸附和润湿性影响的分子模拟[J]. 计算物理, 2021, 38(5): 595-602.

Renyi CAO, Tao HUANG, Linsong CHENG, Zhanwu GAO, Zhihao JIA. Influence of Polar Substance of Crude Oil on Adsorption and Wettability in Water Flooding Reservoir: Molecular Simulation[J]. Chinese Journal of Computational Physics, 2021, 38(5): 595-602.

图/表 12

图1 石英矿物晶胞

Fig.1 Crystal cell of quartz minerals

图2 矿物计算模型

Fig.2 Mineral calculation model

图3 流体模型(a) 己烷; (b) 甲苯; (c) 胶质; (d) 沥青质; (e) 水

Fig.3 Fluid model (a) hexane; (b) toluene; (c) resin; (d) asphaltene; (e) water

图4 4种原油组分和水在石英矿物中的吸附热

Fig.4 Adsorption heat of four crude oil components and water in quartz minerals

图5 4种原油组分和水在石英矿物模型相对密度分布(a) 水和己烷; (b) 水和甲苯; (c) 水和胶质; (d) 水和沥青质

Fig.5 Relative density distributions of four crude oil components and water in quartz mineral model (a) water and hexane; (b) water and toluene; (c) water and resin; (d) water and asphaltene

图6 4种原油组分和水与石英矿物的相互作用能

Fig.6 Interaction energies of four crude oil components and water with quartz minerals

图7 石英矿物表面己烷和水吸附状态随时间的变化(a) 0 ps; (b) 50 ps; (c) 150 ps; (d) 350 ps; (e) 500 ps (图中红色代表氧原子，白色代表氢原子，灰色为碳原子，黄色为硅原子。)

Fig.7 Adsorption state of hexane and water on quartz mineral surface at (a) 0 ps; (b) 50 ps; (c) 150 ps; (d) 350 ps; (e) 500 ps (Red for oxygen, white for hydrogen, gray for carbon and yellow for silicon)

图8 石英矿物表面甲苯和水吸附状态随时间的变化(a) 0 ps; (b) 50 ps; (c) 150 ps; (d) 350 ps; (e) 500 ps

Fig.8 Adsorption state of toluene and water on quartz mineral surface at (a) 0 ps; (b) 50 ps; (c) 150 ps; (d) 350 ps; (e) 500 ps

图9 石英矿物表面胶质和水吸附状态随时间的变化(a) 0 ps; (b) 50 ps; (c) 150 ps; (d) 350 ps; (e) 500 ps

Fig.9 Adsorption state of gum and water on quartz mineral surface at (a) 0 ps; (b) 50 ps; (c) 150 ps; (d) 350 ps; (e) 500 ps

图10 石英矿物表面沥青质和水吸附状态随时间的变化(a) 0 ps; (b) 50 ps; (c) 150 ps; (d) 350 ps; (e) 500 ps

Fig.10 Adsorption state of asphaltene and water on quartz mineral surface at (a) 0 ps; (b) 50 ps; (c) 150 ps; (d) 350 ps; (e) 500 ps

图11 4种原油组分和水占石英矿物的表面积的百分比随时间的变化(a) 水和己烷; (b) 水和甲苯; (c) 水和胶质; (d) 水和沥青质

Fig.11 Percentage of four crude oil components and water on the surface area of quartz minerals as functions of time (a) water and hexane; (b) water and toluene; (c) water and resin; (d) water and asphaltene

表1 原油样品成分分析和接触角测定

Table 1 Composition analysis and contact angle determination of crude oil samples

	沥青质/%	胶质/%	芳香烃/%	饱和烃/%	总收率/%	接触角/°
样品1	4.48	6.91	13.58	73.77	98.97	78.40
样品2	8.23	12.38	21.41	57.41	99.43	88.70
样品3	10.08	12.93	20.84	55.57	99.42	110.70

参考文献 23

1	YANG Y, LIU P, ZHANG W, et al. Effect of the pore size distribution on the displacement efficiency of multiphase flow in porous media[J]. Open Physics, 2016, 14 (1): 610- 616. DOI
2	FENG Q, ZHAO Y, WANG S, et al. Pore-scale oil-water two-phase flow simulation based on phase field method[J]. Chinese Journal of Computational Physics, 2020, 37 (4): 440- 447.
3	ZOU S, SUN C. X-ray micro-computed imaging of wettability characterization for multiphase flow in porous media: A review[J]. Capillarity, 2020, 3 (3): 36- 44. DOI
4	GOLPARVAR A, ZHOU Y, WU K, et al. A comprehensive review of pore scale modeling methodologies for multiphase flow in porous media[J]. Advances in Geo-Energy Research, 2018, 2 (4): 418- 440. DOI
5	CAI J, LI C, SONG K, et al. The influence of salinity and mineral components on spontaneous imbibition in tight sandstone[J]. Fuel, 2020, 269 (1): 117087.
6	MAHMUD B H, MAHMUD W M, ARUMUGAM S. Numerical investigation of optimum ions concentration in low salinity waterflooding[J]. Advances in Geo-Energy Research, 2020, 4 (3): 271- 285. DOI
7	KHISHVAND M, KOHSHOUR I O, ALIZADEH A H, et al. A multi-scale experimental study of crude oil-brine-rock interactions and wettability alteration during low-salinity waterflooding[J]. Fuel, 2019, 250 (15): 117- 131.
8	HOREH M B, AFRA M J S, ROSTAMI B, et al. Role of brine composition and water-soluble components of crude oil on the wettability alteration of a carbonate surface[J]. Energy & Fuels, 2019, 33 (5): 3979- 3988.
9	LIU F, YANG H, WANG J, et al. Salinity-dependent adhesion of model molecules of crude oil at quartz surface with different wettability[J]. Fuel, 2018, 223 (1): 401- 407.
10	汪周华, 赵建飞, 白银, 等. 不同润湿性修饰石英吸附甲烷的模拟研究[J]. 西南石油大学学报(自然科学版), 2019, 41 (6): 28- 34.
11	张立虎, 陆现彩, 刘显东. 黏土矿物表面润湿性的分子动力学模拟研究[C]. 中国矿物岩石地球化学学会: 中国矿物岩石地球化学学会第17届学术年会, 2019: 76-77.
12	柴汝宽, 刘月田, 王俊强, 等. 分子动力学模拟方解石和白云石润湿性[J]. 计算物理, 2019, 36 (4): 474- 482.
13	张文, 龙军, 任强, 等. 沥青质分子聚集行为研究进展[J]. 化工进展, 2019, 38 (5): 2158- 2163.
14	王大喜, 赵玉玲, 潘月秋, 等. 石油胶质结构性质的量子化学研究[J]. 燃料化学学报, 2006, 34 (6): 690- 694. DOI
15	WANG X, DONG B, ZHU Z, et al. Interfacial interaction and diffusion properties of functionalized CNT/polymer systems: Molecular dynamics simulations[J]. Chinese Journal of Computational Physics, 2020, 37 (5): 590- 594.
16	LIU B, SHI J, SHEN Y, et al. A molecular dynamics simulation of methane adsorption in graphite slit-pores[J]. Chinese Journal of Computational Physics, 2013, 30 (5): 693- 699.
17	ZHAN S, SU Y, JIN Z, et al. Effect of water film on oil flow in quartz nanopores from molecular perspectives[J]. Fuel, 2019, 262 (15): 116560.
18	熊健, 刘向君, 梁利喜. 甲烷在官能团化石墨中吸附的分子模拟[J]. 石油学报, 2016, 37 (12): 1528- 1536. DOI
19	TESSON S, FIROOZABADI A. Methane adsorption and self-diffusion in shale kerogen and slit nanopores by molecular simulations[J]. The Journal of Physical Chemistry C, 2018, 122 (41): 23528- 23542. DOI
20	YANG Y, LIU J, YAO J, et al. Adsorption behaviors of shale oil in kerogen slit by molecular simulation[J]. Chemical Engineering Journal, 2020, 387 (1): 124054.
21	陈诵英. 吸附与催化[M]. 郑州: 河南科学技术出版社, 2001: 1- 2.
22	戴宗, 江俊, 李海龙, 等. 海相稠油油藏高倍数水驱岩心润湿性实验及微观机理[J]. 科学技术与工程, 2019, 19 (33): 157- 163. DOI
23	刘汝敏, 康晓东, 辛晶, 等. 分子动力学模拟研究方解石表面润湿性反转机理[J]. 原子与分子物理学报, 2021, 38 (1): 38- 47.

[1]	赵玉龙, 周厚杰, 李洪玺, 文涛, 张芮菡, 张烈辉. 基于水平集方法的低渗砂岩数字岩心气水两相渗流模拟[J]. 计算物理, 2021, 38(5): 585-594.
[2]	阿湖宝, 杨志兵, 胡冉, 陈益峰. 纳米尺度下毛细流动的分子动力学模拟[J]. 计算物理, 2021, 38(5): 603-611.
[3]	刘永智, 解立强, 梁盛德, 朱开礼, 席忠红, 袁方强. C₆₀对细胞膜潜在生物毒性的分子动力学模拟[J]. 计算物理, 2020, 37(4): 479-487.
[4]	柴汝宽, 刘月田, 王俊强, 辛晶, 皮建, 李长勇. 分子动力学模拟方解石和白云石润湿性[J]. 计算物理, 2019, 36(4): 474-482.
[5]	张任良, 狄勤丰, 王新亮, 顾春元, 王文昌. 用格子Boltzmann方法模拟壁面微结构对管流特性的影响[J]. 计算物理, 2011, 28(2): 225-229.