Imbibition Behavior and Fluid Dynamic Distribution of Longmaxi Formation Shale in Pengshui Area

doi:10.19596/j.cnki.1001-246x.8394

Abstract

Abstract:

As the main absorption mode of fracturing fluid in reservoir, imbibition is an important driving force to improve shale gas productivity. In this paper, the Longmaxi formation shale in Pengshui area of Chongqing is studied. Mercury intrusion porosimetry, imbibition under different conditions and NMR tests were carried out successively. It shows that: ① The permeability and porosity of shale are very low, mainly micropores and mesopcres, almost no macropores, and the pore structure is poor; ② The process of shale imbibition can be divided into three stages. With the increase of pressure and temperature, imbibition behavior is enhanced. The imbibition effect of gel breaking fracturing fluid is slightly stronger than that of non-gel breaking fracturing fluid. Surfactant and KCl solution can reduce the imbibition ability of shale; ③ In the process of imbibition, the medium and large pores and fractures are filled with liquid in the initial stage, while the very small pores and fractures are filled first, and then the liquid enters into the slightly larger micropores and microcracks, resulting in a large number of microcracks on the surface of shale.

Key words: shale, imbibition, nuclear magnetic resonance, pore structure, influence factor

CLC Number:

TE371

Yunxuan ZHU, Zhiping LI. Imbibition Behavior and Fluid Dynamic Distribution of Longmaxi Formation Shale in Pengshui Area[J]. Chinese Journal of Computational Physics, 2021, 38(5): 555-564.

Figures/Tables 19

Fig.1 Shale samples of Longmaxi formation in Pengshui area

Table 1 Petrophysical properties of core samples

岩样编号	直径/cm	长度/cm	密度/(g·cm^-3)	孔隙度/%	渗透率/(10^-3 μm²)
1	2.53	2.72	2.62	3.91	0.007
2	2.60	2.68	2.62	3.99	0.007
3	2.55	2.72	2.60	3.87	0.005
4	2.59	2.67	2.57	3.75	0.005
5	2.53	2.71	2.64	4.25	0.006
6	2.50	2.69	2.63	3.80	0.006
7	2.54	2.70	2.63	3.77	0.007
8	2.51	2.66	2.56	3.89	0.006

Fig.2 Experimental device of imbibition volume method

Fig.3 EM-2 high pressure imbition instrument

Fig.4 Nuclear magnetic resonance core analyzer

Table 2 Test results of capillary pressure curves

岩样编号	半径均值/μm	仪器最大退出效率/%	排驱压力/MPa	汞饱和度/%		孔喉半径/μm			孔喉分布		渗透率分布
岩样编号	半径均值/μm	仪器最大退出效率/%	排驱压力/MPa	最大	最终剩余	最大	平均	中值	峰位/μm	峰值/%	峰位/μm	峰值/%
1	0.015	91.772	13.775	97.955	8.060	0.053	0.013	0.009	0.006	18.909	0.040	56.847
2	0.012	88.374	13.776	95.751	11.132	0.053	0.012	0.008	0.006	21.117	0.040	41.743

Fig.5 Capillary pressure curves of samples

Fig.6 Distribution of core pore throat

Fig.7 Relations between the imbibition amount and time under different pressures

Fig.8 Relations between imbibition amount and time under different pressures

Fig.9 Relations between imbibition speed and time under different pressures

Fig.10 Relations between imbibition amount/imbibition speed and time under different temperatures

Table 3 Imbibition results of different fracturing fluids

渗吸条件	渗吸量/ml	初始渗吸速率/(ml·h^-1)
0.1 MPa未破胶	1.3	0.23
0.1 MPa破胶	1.35	0.28
5 MPa未破胶	1.4	0.26
5 MPa破胶	1.43	0.32
10 MPa未破胶	1.48	0.31
10 MPa破胶	1.52	0.35

Fig.11 Relations between imbibition amount/imbibition speed and time of different fracturing fluids

Fig.12 Wetting angle of shale core before and after surfactant treatment (a) before treatment; (b) after treatment

Fig.13 Influence of different liquids on spontaneous-imbibition ability

Fig.14 NMR T2 spectra under different imbibition times

Fig.15 NMR T2 spectra under different pressures

Fig.16 NMR T2 spectra under different temperatures

References 27

1	DING M C, WU M L, LI X, et al. Characteristics of transient pressure for multiple fractured horizontal wells in fractal fractured shale gas reservoirs[J]. Chinese Journal of Computational Physics, 2019, 36 (5): 559- 568.
2	邹才能, 赵群, 丛连铸, 等. 中国页岩气开发进展、潜力及前景[J]. 天然气工业, 2021, 41 (1): 1- 14.
3	王雷, 徐康泰. 页岩储层水力压裂体积改造实现方法研究[J]. 科学技术与工程, 2014, 14 (36): 183- 188.
4	申颍浩, 葛洪魁, 宿帅, 等. 页岩气储层的渗吸动力学特性与水锁解除潜力[J]. 中国科学, 2017, 47 (11): 84- 94.
5	DU D F, WANG Y Y, FU J G, et al. Shale gas seepage mechanism and transient pressure analysis[J]. Chinese Journal of Computational Physics, 2015, 32 (1): 51- 57.
6	杨柳, 葛洪魁, 申颍浩, 等. 一种评价页岩储层压裂液吸收的新方法[J]. 科学技术与工程, 2016, 16 (24): 48- 53.
7	LUCAS R. Rate of capillary ascension of liquids[J]. Kolloid-Zeitschrift, 1918, 23 (1): 15- 22. DOI
8	WASHBURN E W. The dynamics of capillary flow[J]. Physical Review Journals Archive, 1921, 17 (3): 273- 283.
9	HANDY L L. Determination of effective capillary pressures for porous media from imbibition data[J]. Transactions of the AIME, 1960, 219 (5): 75- 80.
10	CAI J C, YU B M, MEI M F, et al. Capillary rise in a single tortuous capillary[J]. Chinese Physics Letters, 2010, 27 (5): 148- 151.
11	CAI J C, YU B M, ZOU M Q, et al. Fractal characterization of spontaneous co-current imbibition in porous media[J]. Energy & Fuels, 2010, 24 (3): 1860- 1867.
12	ROYCHAUDHURI B, TSOTSIS T T, JESSEN K. An experimental investigation of spontaneous imbibition in gas shales[J]. Journal of Petroleum Science and Engineering, 2013, 111, 87- 97. DOI
13	ROYCHAUDHURI B, TSOTSIS T T, JESSEN K. Shale-fluid interactions during forced imbibition and flow-back[J]. Journal of Petroleum Science and Engineering, 2019, 172, 443- 453. DOI
14	SUN Y P, BAI B J, WEI M Z. Microfracture and surfactant impact on linear cocurrent brine imbibition in gas-saturated shale[J]. Energy & Fuels, 2015, 29 (3): 1438- 1446.
15	HABIBI A, DEHGHANPOUR H, BINAZADEH M, et al. Advances in understanding wettability of tight oil formations: A Montney case study[J]. SPE Reservoir Evaluation & Engineering, 2016, 19 (04): 583- 603.
16	AKBARABADI M, SARAJI S, PIRI M, et al. Nano-scale experimental investigation of in-situ wettability and spontaneous imbibition in ultra-tight reservoir rocks[J]. Advances in Water Resources, 2017, 107, 160- 179.
17	顾雅頔, 喻高明, 李桂姗. 低渗致密砂岩储层孔隙结构特征及自发渗吸实验[J]. 科学技术与工程, 2019, 19 (32): 139- 145.
18	ZHOU H D, ZHANG Q S, DAI C L, et al. Experimental investigation of spontaneous imbibition process of nanofluid in ultralow permeable reservoir with nuclear magnetic resonance[J]. Chemical Engineering Science, 2019, 201, 212- 221.
19	LIU J R, SHEN J J, WANG X K, et al. Experimental study of wettability alteration and spontaneous imbibition in Chinese shale oil reservoirs using anionic and nonionic surfactants[J]. Journal of Petroleum Science and Engineering, 2019, 175, 624- 633.
20	WANG F Y, ZHAO J Y. A mathematical model for co-current spontaneous water imbibition into oil-saturated tight sandstone: Upscaling from pore-scale to core-scale with fractal approach[J]. Journal of Petroleum Science and Engineering, 2019, 178, 376- 388.
21	冀昆, 郭少斌, 李新, 等. 溶孔发育的含沥青质碳酸盐岩核磁共振特征分析—以四川盆地高磨地区龙王庙组储层为例[J]. 天然气地球科学, 2017, 28 (8): 1257- 1263.
22	CHENG Z L, WANG Q, NING Z F, et al. Experimental investigation of countercurrent spontaneous imbibition in tight sandstone using nuclear magnetic resonance[J]. Energy & Fuels, 2018, 32 (6): 6507- 6517.
23	王敉邦, 蒋林宏, 包建银, 等. 渗吸实验描述与方法适用性评价[J]. 石油化工应用, 2015, 34 (12): 102- 105.
24	任凯, 葛洪魁, 杨柳, 等. 页岩自吸实验及其在返排分析中的应用[J]. 科学技术与工程, 2015, 15 (30): 106- 109.
25	GE X M, FAN Y R, ZENG Q D, et al. Analysis of NMR transversal relaxation based on ADI-FDTD numerical simulation[J]. Chinese Journal of Computational Physics, 2013, 30 (2): 237- 243.
26	姚艳斌, 刘大锰. 基于核磁共振弛豫谱的煤储层岩石物理与流体表征[J]. 煤炭科学技术, 2016, 44 (6): 14- 22.
27	朱云轩. 彭水地区常压页岩气藏物性特征及压裂液渗吸规律研究[D]. 北京: 中国地质大学(北京), 2020.

[1]	Yuanqiang ZHU, Saisai JIN, Qingqing SUN. Adsorption Characteristics of N₂ on Shale Kerogen [J]. Chinese Journal of Computational Physics, 2021, 38(6): 707-712.
[2]	Jianchao CAI. Some Key Issues and Thoughts on Spontaneous Imbibition in Porous Media [J]. Chinese Journal of Computational Physics, 2021, 38(5): 505-512.
[3]	Zhenjie ZHANG, Jianyuan FENG, Jianchao CAI, Kangli CHEN, Qingbang MENG. Driving Force for Spontaneous Imbibition Under Different Boundary Conditions [J]. Chinese Journal of Computational Physics, 2021, 38(5): 513-520.
[4]	Jiangtao ZHENG, Ninghong JIA, Huifang HU, Yong YANG, Yang JU, Moran WANG. Study on Liquid-Liquid Spontaneous Imbibition Dynamics in Bifurcated Channels [J]. Chinese Journal of Computational Physics, 2021, 38(5): 543-554.
[5]	Jianchun GUO, Liang TAO, Chi CHEN, Yuhang ZHAO, Songgen HE, Yuxuan LIU. Water Imbibition Law of Longmaxi Formation Shale in the South of Sichuan Basin [J]. Chinese Journal of Computational Physics, 2021, 38(5): 565-572.
[6]	DING Mingcai, WU Minglu, LI Xuan, YAO Jun. Characteristics of Transient Pressure for Multiple Fractured Horizontal Wells in Fractal Fractured Shale Gas Reservoirs [J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2019, 36(5): 559-568.
[7]	XU Guoliang, ZHU Yiping, FANG Lin, DU Yang, HUANG Xiaoming. Three-dimensional Fractal Reconstruction Technique and Leakage Characteristics of Micro-pore Sealing Interfaces [J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2019, 36(4): 440-448.
[8]	DU Dianfa, WANG Yanyan, FU Jingang, SUN Zhaobo, QIAO Ni. Shale Gas Seepage Mechanism and Transient Pressure Analysis [J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2015, 32(1): 51-57.
[9]	GE Xinmin, FAN Yiren, ZENG Qingdong, WANG Mingfang, XU Yongjun. Analysis of NMR Transversal Relaxation Based on ADI-FDTD Numerical Simulation [J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2013, 30(2): 237-243.
[10]	WENG Aihua, GAO Lijuan. Surface Nuclear Magnetic Resonance Imaging in Layered Electrically Conductive Media [J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2008, 25(2): 203-207.