A pressure drop model of post-fracturing shut-in considering the effect of fracturing-fluid imbibition and oil replacement

被引：0
|
作者：
Wang F. [1 ]
Ruan Y. [1 ]
Chen Q. [1 ]
Zhang S. [1 ]
机构：
[1] State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing
来源：
Shiyou Kantan Yu Kaifa/Petroleum Exploration and Development | 2021年 / 48卷 / 06期
关键词：
Fracture network; Hydraulic fracturing; Imbibition oil replacement; Pressure drop; Shale oil; Shut-in;
D O I：
10.11698/PED.2021.06.17
中图分类号：
学科分类号：
摘要：
Since the production regime of shut-in after fracturing is generally adopted for wells in shale oil reservoir, a shut-in pressure drop model coupling wellbore-fracture network-reservoir oil-water two-phase flow has been proposed. The model takes into account the effects of wellbore afterflow, fracture network channeling, and matrix imbibition and oil exchange after stop of pumping. The simulated log-log curve of pressure-drop derivative by the model presents W-shape, reflecting the oil-water displacement law between wellbore, fracture network and matrix, and is divided into eight main control flow stages according to the soaking time. In the initial stage of pressure drop, the afterflow dominates; in the early stage, the pressure drop is controlled by the cross-flow and leakoff of the fracture system, and the fractures close gradually; in the middle stage of pressure drop, matrix imbibition and oil exchange take dominance, and the fracturing fluid loss basically balances with oil replaced from matrix; the late stage of pressure drop is the reservoir boundary control stage, and the leakoff rate of fracturing-fluid and oil exchange rate decrease synchronously till zero. Finally, the fracture network parameters such as half-length of main fracture, main fracture conductivity and secondary fracture density were inversed by fitting the pressure drop data of five wells in Jimsar shale oil reservoir, and the water imbibition volume of matrix and the oil replacement volume in fracture were calculated by this model. The study results provide a theoretical basis for comprehensively evaluating the fracturing effect of shale oil horizontal wells and understanding the oil-water exchange law of shale reservoir after fracturing. © 2021, The Editorial Board of Petroleum Exploration and Development. All right reserved.
引用
收藏
页码：1250 / 1257
页数：7
相关论文
共 30 条
  • [1] HU Suyun, ZHAO Wenzhi, HOU Lianhua, Et al., Development potential and technical strategy of continental shale oil in China, Petroleum Exploration and Development, 47, 4, pp. 819-828, (2020)
  • [2] GE H, YANG L, SHEN Y, Et al., Experimental investigation of shale imbibition capacity and the factors influencing loss of hydraulic fracturing fluids, Petroleum Science, 12, 4, pp. 636-650, (2015)
  • [3] YU Fuwei, JIANG Hanqiao, FAN Zhen, Et al., Features and imbibition mechanisms of WinsorⅠtype surfactant solution in oil-wet porous media, Petroleum Exploration and Development, 46, 5, pp. 950-958, (2019)
  • [4] XIAO L, ZHU G, ZHANG L, Et al., Effects of pore-size disorder and wettability on forced imbibition in porous media, Journal of Petroleum Science and Engineering, 201, (2021)
  • [5] LIN H, ZHANG S, WANG F, Et al., Experimental investigation on imbibition-front progression in shale based on nuclear magnetic resonance, Energy & Fuels, 30, 11, pp. 9097-9105, (2016)
  • [6] GAO Z, HU Q., Initial water saturation and imbibition fluid affect spontaneous imbibition into Barnett shale samples, Journal of Natural Gas Science & Engineering, 34, pp. 541-551, (2016)
  • [7] YANG Zhengming, LIU Xuewei, LI Haibo, Et al., Analysis on the influencing factors of imbibition and the effect evaluation of imbibition in tight reservoirs, Petroleum Exploration and Development, 46, 4, pp. 739-745, (2019)
  • [8] OSTEBO A P., Early-and late-time analytical solutions for cocurrent spontaneous imbibition and generalized scaling, SPE Journal, 26, 1, pp. 220-240, (2021)
  • [9] TU J, SHENG J J., Effect of pressure on imbibition in shale oil reservoirs with wettability considered, Energy & Fuels, 34, 4, pp. 4260-4272, (2020)
  • [10] ZHANG S, LI Y, PU H., Studies of the storage and transport of water and oil in organic-rich shale using vacuum imbibition method, Fuel, 266, (2020)
123