Numerical simulation of fractured imbibition in a shale oil reservoir based on the discrete fracture model

XU Rong-li; GUO Tian-kui; QU Zhan-qing; CHEN Ming; QIN Jian-hua; MOU Shan-bo; CHEN Huan-peng; ZHANG Yue-long

doi:10.13374/j.issn2095-9389.2021.08.30.007

Volume 44 Issue 3

Jan. 2022

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Article Navigation > Chinese Journal of Engineering > 2022 > 44(3): 451-463

XU Rong-li, GUO Tian-kui, QU Zhan-qing, CHEN Ming, QIN Jian-hua, MOU Shan-bo, CHEN Huan-peng, ZHANG Yue-long. Numerical simulation of fractured imbibition in a shale oil reservoir based on the discrete fracture model[J]. Chinese Journal of Engineering, 2022, 44(3): 451-463. doi: 10.13374/j.issn2095-9389.2021.08.30.007

Citation:

XU Rong-li, GUO Tian-kui, QU Zhan-qing, CHEN Ming, QIN Jian-hua, MOU Shan-bo, CHEN Huan-peng, ZHANG Yue-long. Numerical simulation of fractured imbibition in a shale oil reservoir based on the discrete fracture model[J]. Chinese Journal of Engineering, 2022, 44(3): 451-463. doi: 10.13374/j.issn2095-9389.2021.08.30.007

Citation:

XU Rong-li, GUO Tian-kui, QU Zhan-qing, CHEN Ming, QIN Jian-hua, MOU Shan-bo, CHEN Huan-peng, ZHANG Yue-long. Numerical simulation of fractured imbibition in a shale oil reservoir based on the discrete fracture model[J]. Chinese Journal of Engineering, 2022, 44(3): 451-463. doi: 10.13374/j.issn2095-9389.2021.08.30.007

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Numerical simulation of fractured imbibition in a shale oil reservoir based on the discrete fracture model

doi: 10.13374/j.issn2095-9389.2021.08.30.007

1.
School of Petroleum Engineering, China University of Petroleum, Qingdao 266580, China
2.
Research Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Karamay 834000, China
3.
Xinjiang Zhengtong Petroleum and Natural Gas Co. LTD, Karamay 834000, China

More Information

Corresponding author: E-mail: guotiankui@126.com
Received Date: 2021-08-30
Available Online: 2021-10-08
Publish Date: 2022-01-08

Abstract

Abstract

When a shale oil reservoir contains a mass of clay minerals, the salinity of formation water can reach up to 4.786×10³ mol·m^?3 and the formation water and low salinity fracturing fluid create significant osmotic pressure during the fracturing process. To investigate the effect of osmotic pressure on the imbibition effect, a two-dimensional, oil-water, two-phase, discrete fracture network model was established. This model comprehensively considers osmotic pressure and capillary force. Additionally, a series of studies were carried out to explore the influence of osmotic pressure, capillary force, shut-in time, salt concentration, membrane efficiency, and the proportion of branch fracture area on the imbibition effect in shale oil reservoirs during fracturing fluid pumping and shut-in. The results show that: (1) Filtration is mainly influenced by pressure difference, capillary force, and osmotic pressure, and pressure difference is the key control mechanism of filtration. (2) The shut-in time has a great influence on the imbibition effect of fracturing fluid. The imbibition amount in the first 15 d can reach 80% of the total imbibition amount when the well is shut in for 50 d, leading to the shut-in pressure spreading to the fracturing interval on either side. (3) Osmotic pressure takes longer to reach equilibrium than diffusion pressure. Osmotic pressure takes 50 d to shut in the well and make the salinity near the fracture reach 600 mol·m^?3 when the salinity of local layer water is 4.786×10³ mol·m^?3. (4) As pressure difference is the main factor that affects the imbibition effect and the effect of shale film efficiency on seepage pressure diffusion is weak, the extent of imbibition increases by only 4% when the shale film efficiency increases from 5% to 30%. (5) Water saturation is controlled using hydraulic fractures through small spacing during shut-in, and the influence of branch fractures on water saturation is limited in intensive volume fracturing to horizontal wells.
- shale oil reservoir,
- imbibition,
- osmotic pressure,
- discrete fracture model,
- numerical simulation,
- shut-in time

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References(35)

References

[1]	胥云, 雷群, 陳銘, 等. 體積改造技術理論研究進展與發展方向. 石油勘探與開發, 2018, 45(5):874 Xu Y, Lei Q, Chen M, et al. Progress and development of volume stimulation techniques. Petroleum Explor Dev, 2018, 45(5): 874
[2]	Denney D. Thirty years of gas-shale fracturing: What have we learned? J Petroleum Technol, 2010, 62(11): 88
[3]	Makhanov K, Dehghanpour H, Kuru E. An experimental study of spontaneous imbibition in Horn River shales // SPE Canadian Unconventional Resources Conference. Alberta, 2012
[4]	Dehghanpour H, Zubair H A, Chhabra A, et al. Liquid intake of organic shales. Energy Fuels, 2012, 26(9): 5750 doi: 10.1021/ef3009794
[5]	Pagels M, Hinkel J J, Willberg D M. Measuring capillary pressure tells more than pretty pictures // SPE International Symposium and Exhibition on Formation Damage Control. Louisiana, 2012: SPE-151729-MS
[6]	Cheng Y. Impact of water dynamics in fractures on the performance of hydraulically fractured wells in gas-shale reservoirs. J Can Pet Technol, 2012, 51(2): 143
[7]	Wang M Y, Leung J Y. Numerical investigation of coupling multiphase flow and geomechanical effects on water loss during hydraulic-fracturing flowback operation. SPE Reserv Eval Eng, 2016, 19(3): 520 doi: 10.2118/178618-PA
[8]	Meng M M, Ge H K, Ji W M, et al. Investigation on the variation of shale permeability with spontaneous imbibition time: Sandstones and volcanic rocks as comparative study. J Nat Gas Sci Eng, 2015, 27: 1546 doi: 10.1016/j.jngse.2015.10.019
[9]	Wang S, Javadpour F, Feng Q H. Confinement correction to mercury intrusion capillary pressure of shale nanopores. Sci Rep, 2016, 6: 20160 doi: 10.1038/srep20160
[10]	張濤, 李相方, 楊立峰, 等. 關井時機對頁巖氣井返排率和產能的影響. 天然氣工業, 2017, 37(8):48 doi: 10.3787/j.issn.1000-0976.2017.08.006 Zhang T, Li X F, Yang L F, et al. Effects of shut-in timing on flowback rate and productivity of shale gas wells. Nat Gas Ind, 2017, 37(8): 48 doi: 10.3787/j.issn.1000-0976.2017.08.006
[11]	Dehghanpour H, Lan Q, Saeed Y, et al. Spontaneous imbibition of brine and oil in gas shales: Effect of water adsorption and resulting microfractures. Energy Fuels, 2013, 27(6): 3039 doi: 10.1021/ef4002814
[12]	楊柳. 壓裂液在頁巖儲層中的吸收及其對工程的影響[學位論文]. 北京: 中國石油大學(北京), 2016 Yang L. Fracturing Fluid Imbibition into Gas Shale and Its Impact on Engineering [Dissertation]. Beijing: China University of Petroleum (Beijing), 2016
[13]	Zhou Z. The Impact of Capillary Imbibition and Osmosis During Hydraulic Fracturing of Shale Formations. Colorado: ProQuest Dissertations Publishing, 2015
[14]	Fakcharoenphol P, Torcuk M, Bertoncello A, et al. Managing shut-in time to enhance gas flow rate in hydraulic fractured shale reservoirs: a simulation study // SPE Annual Technical Conference and Exhibition. New Orleans, 2013: SPE-166098-MS
[15]	Fakcharoenphol P, Kurtoglu B, Kazemi H, et al. The effect of osmotic pressure on improve oil recovery from fractured shale formations // SPE Unconventional Resources Conference. The Woodlands, 2014: SPE-168998-MS
[16]	王飛, 潘子晴. 化學勢差驅動下的頁巖儲集層壓裂液返排數值模擬. 石油勘探與開發, 2016, 43(6):971 Wang F, Pan Z Q. Numerical simulation of chemical potential dominated fracturing fluid flowback in hydraulically fractured shale gas reservoirs. Petroleum Explor Dev, 2016, 43(6): 971
[17]	Almulhim A, Alharthy N, Tutuncu A N, et al. Impact of imbibition mechanism on flowback behavior: a numerical study // Abu Dhabi International Petroleum Exhibition and Conference. Abu Dhabi, 2014: SPE-171799-MS
[18]	王家祿, 劉玉章, 陳茂謙, 等. 低滲透油藏裂縫動態滲吸機理實驗研究. 石油勘探與開發, 2009, 36(1):86 doi: 10.3321/j.issn:1000-0747.2009.01.011 Wang J L, Liu Y Z, Chen M Q, et al. Experimental study on dynamic imbibition mechanism of low permeability reservoirs. Petroleum Explor Dev, 2009, 36(1): 86 doi: 10.3321/j.issn:1000-0747.2009.01.011
[19]	朱維耀, 岳明, 劉昀楓, 等. 中國致密油藏開發理論研究進展. 工程科學學報, 2019, 41(9):1103 Zhu W Y, Yue M, Liu Y F, et al. Research progress on tight oil exploration in China. Chin J Eng, 2019, 41(9): 1103
[20]	Zhang T, Li X F, Li J, et al. Numerical investigation of the well shut-in and fracture uncertainty on fluid-loss and production performance in gas-shale reservoirs. J Nat Gas Sci Eng, 2017, 46: 421 doi: 10.1016/j.jngse.2017.08.024
[21]	Wang F, Pan Z Q, Zhang Y C, et al. Simulation of coupled hydro-mechanical-chemical phenomena in hydraulically fractured gas shale during fracturing-fluid flowback. J Petroleum Sci Eng, 2018, 163: 16 doi: 10.1016/j.petrol.2017.12.029
[22]	Wang X H, Li L, Wang M, et al. A discrete fracture model for two-phase flow involving the capillary pressure discontinuities in fractured porous media. Adv Water Resour, 2020, 142: 103607 doi: 10.1016/j.advwatres.2020.103607
[23]	Li Z K, Cao W D, Liu Z F, et al. The advanced embedded discrete fracture model considering the capillary pressure difference. J Por Media, 2020, 23(10): 969 doi: 10.1615/JPorMedia.2020034976
[24]	Zhang K N, Woodbury A D. A Krylov finite element approach for multi-species contaminant transport in discretely fractured porous media. Adv Water Resour, 2002, 25(7): 705 doi: 10.1016/S0309-1708(02)00084-2
[25]	Takeda M, Hiratsuka T, Ito K, et al. Development and application of chemical osmosis simulator based on TOUGH2 // 2012 TOUGH2 Symposium of Lawrence Berkeley National Laboratory Berkeley. California, 2012: 1
[26]	Fritz S J. Ideality of clay membranes in osmotic processes: A review. Clays Clay Miner, 1986, 34(2): 214 doi: 10.1346/CCMN.1986.0340212
[27]	Guo T K, Wang X Z, Li Z, et al. Numerical simulation study on fracture propagation of zipper and synchronous fracturing in hydrogen energy development. Int J Hydrog Energy, 2019, 44(11): 5270 doi: 10.1016/j.ijhydene.2018.08.072
[28]	朱維耀, 馬東旭, 朱華銀, 等. 頁巖儲層應力敏感性及其對產能影響. 天然氣地球科學, 2016, 27(5):892 doi: 10.11764/j.issn.1672-1926.2016.05.0892 Zhu W Y, Ma D X, Zhu H Y, et al. Stress sensitivity of shale gas reservoir and its influence on productivity. Nat Gas Geosci, 2016, 27(5): 892 doi: 10.11764/j.issn.1672-1926.2016.05.0892
[29]	Ghorayeb K, Firoozabadi A. Numerical study of natural convection and diffusion in fractured porous media. SPE J, 2000, 5(1): 12 doi: 10.2118/51347-PA
[30]	Ma T R, Xu H, Guo C B, et al. A discrete fracture modeling approach for analysis of coalbed methane and water flow in a fractured coal reservoir. Geofluids, 2020, 2020: 1
[31]	張慶福, 黃朝琴, 姚軍, 等. 基于多尺度混合有限元的離散裂縫兩相滲流數值模擬. 科學通報, 2017, 62(13):1392 doi: 10.1360/N972016-00584 Zhang Q F, Huang Z Q, Yao J, et al. Two-phase numerical simulation of discrete fracture model based on multiscale mixed finite element method. Chin Sci Bull, 2017, 62(13): 1392 doi: 10.1360/N972016-00584
[32]	黃朝琴, 高博, 王月英, 等. 基于模擬有限差分法的離散裂縫模型兩相流動模擬. 中國石油大學學報(自然科學版), 2014, 38(6):97 Huang Z Q, Gao B, Wang Y Y, et al. Two-phase flow simulation of discrete fracture model using a novel mimetic finite difference method. J China Univ Pet, 2014, 38(6): 97
[33]	鄭民, 李建忠, 吳曉智, 等. 致密儲集層原油充注物理模擬——以準噶爾盆地吉木薩爾凹陷二疊系蘆草溝組為例. 石油勘探與開發, 2016, 43(2):219 Zheng M, Li J Z, Wu X Z, et al. Physical modeling of oil charging in tight reservoirs: A case study of Permian Lucaogou Formation in Jimsar Sag, Junggar Basin, NW China. Pet Explor Dev, 2016, 43(2): 219
[34]	孫兵, 劉立峰, 丁江輝. 致密油水平井產能主控地質因素研究. 特種油氣藏, 2017, 24(2):115 doi: 10.3969/j.issn.1006-6535.2017.02.023 Sun B, Liu L F, Ding J H. Main geologic factors controlling the productivity of horizontal wells in tight oil reservoirs. Special Oil Gas Reserv, 2017, 24(2): 115 doi: 10.3969/j.issn.1006-6535.2017.02.023
[35]	Schlemmer R, Friedheim J E, Growcock F B, et al. Chemical osmosis, shale, and drilling fluids. SPE Drill Complet, 2003, 18(4): 318 doi: 10.2118/86912-PA