Lithologic Reservoirs ›› 2026, Vol. 38 ›› Issue (3): 190-200.doi: 10.12108/yxyqc.20260317

• PETROLEUM ENGINEERING AND OIL & GAS FIELD DEVELOPMENT • Previous Articles    

Four-dimensional in-situ stress evolution and optimization method for refracturing timing in shale oil reservoir horizontal wells： A case study of Triassic Chang 7 member in Qingcheng Oilfield, Ordos Basin

REN Jiawei1,2(), LI Li3, WANG Deyu1, BAI Xiaohu1, KANG Bo1, BAI Yuen1, BAI Jianwen1, CHEN Junbin2   

  1. 1 Oil & Gas Technology Research Institute, PetroChina Changqing Oilfield Company, Xi’an 710065, China
    2 College of Petroleum Engineering, Xi’an Shiyou University, Xi’an 710065, China
    3 No. 5 Oil Production Plant, PetroChina Changqing Oilfield Company, Xi’an 710018, China
  • Received:2025-09-25 Revised:2025-10-13 Online:2026-05-01 Published:2026-03-18

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Abstract:

Based on the concept of geology-engineering integration, a multi-physics field coupled model of fracture network-seepage-stress applicable to the entire development cycle of shale oil old wells in Qingcheng Oilfield of Ordos Basin was established. Multi-field coupled numerical simulations of refracturing in shale oil horizontal wells were conducted, and a stress recovery index along with an optimization method for refracturing timing was proposed. The results show that: （1） By establishing a seepage model, stress model, and their data interface program, the multi-physics field coupled model of fracture network-seepage-stress was solved by using cross coupling iterative algorithm, with history-matching accuracy of 93%, verifying the accuracy of the model and effectively applying it to the development and production of shale oil reservoirs in Qingcheng Oilfield, Ordos Basin. （2） After six years of production in the target well of Qingcheng Oilfield, the reservoir pressure near hydraulic fractures decreased by 1 MPa, while the maximum and minimum horizontal principal stresses declined by 2.6 MPa and 4.2 MPa, respectively, and the maximum principal stress direction rotated by 84°. Following pre-fracturing energy supplement of 10 000 m³, the maximum principal stress deflection angle decreased from 84° to 20°, resulting in a significant increase in the length and volume of refracturing-induced fractures, and that further proves the importance of implementing pre-fracturing energy supplement. （3） The stress recovery index can be proposed to cha-racterize the degree of in-situ stress recovery during development process of Qingcheng Oilfield, and a stress recovery index of 0.70 was identified as the optimal time for refracturing implementation. The influencing factors of refracturing timing include natural fracture density, matrix permeability, and initial hydraulic fracturing scale.

Key words: shale reservoir, refracturing, four-dimensional geostress, seepage-stress coupling, timing optimization, Chang 7 member, Triassic, Qingcheng Oilfield, Ordos Basin

CLC Number: 

  • TE357.1

Fig. 1

Location of refracturing test area in Qingcheng Oilfield (a) and comprehensive stratigraphic column of Triassic Chang 7 member (b), Ordos Basin"

Fig. 2

Complex fracture morphology in 3D real physical domain (a) and corresponding matrix and fracture grid in the computational domain (b)"

Fig. 3

Calculation process of seepage-stress real-time coupling simulation"

Table 1

Basic parameters of the 3D geological model of Triassic Chang 7 member in Qingcheng Oilfield, Ordos Basin"

属性 数值 属性 数值
有效厚度/m 18 含油饱和度 0.542
油藏埋深/m 1 520 原油黏度/（mPa·s） 7.3
平均孔隙度 0.09 原始地层压力/MPa 15.8
平均渗透率/mD 0.82 原油饱和压力/MPa 5.6
杨氏模量/GPa 21.37 泊松比 0.23
水平最大主应力/MPa 26.0 水平最小主应力/MPa 22.0

Fig. 4

Fracture network-seepage-stress models and historical fitting results of Triassic Chang 7 member in the target well in Qingcheng Oilfield, Ordos Basin"

Fig. 5

Fracture network-seepage-stress model simulated formation pressure distribution profile along the wellbore direction of Triassic Chang 7 member of the target well in Qingcheng Oilfield in Ordos Basin"

Fig. 6

Fracture network-seepage-stress model simulated variation law of horizontal principal stress during the exploitation of Triassic Chang 7 member of the target well in Qingcheng Oilfield in Ordos Basin"

Fig. 7

Fracture network-seepage-stress model simulated variation law of geostress deflection angle during the exploitation of Triassic Chang 7 member of the target well in Qingcheng Oilfield in Ordos Basin"

Fig. 8

Fracture network-seepage-stress model simulated refracturing propagation under long-term injection and production conditions of Triassic Chang 7 member of the target well in Qingcheng Oilfield, Ordos Basin"

Fig. 9

Fracture network-seepage-stress model simulated variation law of geostress after fluid injection and energy supplement of Triassic Chang 7 member of the target well in Qingcheng Oilfield in Ordos Basin"

Fig. 10

Fracture network-seepage-stress model simulated variation law of stress magnitude and direction with diffe-rent injection volume of Triassic Chang 7 member of the target well in Qingcheng Oilfield in Ordos Basin"

Fig. 11

Fracture network-seepage-stress model simulated the fracture propagation law under different supplement fluid volume before fracturing of Triassic Chang 7 member of the target well in Qingcheng Oilfield， Ordos Basin"

Fig. 12

Fracture network-seepage-stress model simulated the relationship of stress recovery index and refracturing transformation volumetric with the level of formation pressure of Triassic Chang 7 member of the target well in Qingcheng Oilfield， Ordos Basin"

Fig. 13

Fracture network-seepage-stress model simulated the variation of stress recovery index with the level of formation pressure under different natural fracture density of Triassic Chang 7 member in the target well in Qingcheng Oilfield， Ordos Basin"

Fig. 14

Fracture network-seepage-stress model simulated the variation of stress recovery index with the level of formation pressure under different matrix permeability of Triassic Chang 7 member of the target well in Qingcheng Oilfield, Ordos Basin"

Fig. 15

Fracture network-seepage-stress model simulated the variation of stress recovery index with the level of formation pressure under different fracture spacing of Triassic Chang 7 member of the target well in Qingcheng Oilfield, Ordos Basin"

[1] 王子昕, 柳广弟, 袁光杰, 等. 鄂尔多斯盆地庆城地区三叠系长7段烃源岩特征及控藏作用[J]. 岩性油气藏, 2024, 36(5):133-144.
WANG Zixin, LIU Guangdi, YUAN Guangjie, et al. Characte-ristics and reservoir control of source rocks of Triassic Chang 7 member in Qingcheng area,Ordos Basin[J]. Lithologic Reservoirs, 2024, 36(5):133-144.
[2] 樊建明, 杨子清, 李卫兵, 等. 鄂尔多斯盆地长7致密油水平井体积压裂开发效果评价及认识[J]. 中国石油大学学报(自然科学版), 2015, 39(4):103-110.
FAN Jianming, YANG Ziqing, LI Weibing, et al. Assessment of fracturing treatment of horizontal wells using SRV technique for Chang-7 tight oil reservoir in Ordos Basin[J]. Journal of China University of Petroleum(Edition of Natural Science), 2015, 39(4):103-110.
[3] 韩婧婧, 刘建, 武龙. 鄂尔多斯盆地长6致密砂岩油藏压裂技术研究[J]. 岩性油气藏, 2017, 29(1):130-134.
HAN Jingjing, LIU Jian, WU Long. Fracturing technology of Chang 6 tight sandstone reservoir in Ordos Basin[J]. Lithologic Reservoirs, 2017, 29(1):130-134.
[4] ATTIA A, BRADY J, LAWRENCE M, et al. Validating refrac effectiveness with carbon rod conveyed distributed fiber optics in the Barnett Shale for Devon Energy[R]. Woodlands,SPE Hydraulic Fracturing Technology Conference, 2019.
[5] DIAKHATE M, GAZAWI A, BARREE B, et al. Refracturing on horizontal wells in the eagle ford shale in South Texas-one operator’s perspective[R]. Woodlands,SPE Hydraulic Fracturing Technology Conference, 2015.
[6] 雷征东, 王正茂, 慕立俊, 等. 致密油多场重构驱渗结合提高采收率技术[J]. 石油勘探与开发, 2024, 51(1):137-146.
LEI Zhengdong, WANG Zhengmao, MU Lijun, et al. A technique for enhancing tight oil recovery by multi-field reconstruction and combined displacement and imbibition[J]. Petroleum Exploration and Development, 2024, 51(1):137-146
[7] 任佳伟, 王贤君, 张先敏, 等. 大庆致密油藏水平井重复压裂及裂缝参数优化模拟[J]. 断块油气田, 2020, 27(5):638-642.
REN Jiawei, WANG Xianjun, ZHANG Xianmin, et al. Refracturing and fracture parameters optimization simulation for horizontal well in Daqing tight oil reservoir[J]. Fault-Block Oil & Gas Field, 2020, 27(5):638-642.
[8] 苏良银, 白晓虎, 陆红军, 等. 长庆超低渗透油藏低产水平井重复改造技术研究及应用[J]. 石油钻采工艺, 2017, 39(4):521-527.
SU Liangyin, BAI Xiaohu, LU Hongjun, et al. Research and application of re-fracturing technology for low-production horizontal wells in ultra-low permeability reservoirs in Changqing Oilfield[J]. Oil Drilling & Production Technology, 2017, 39(4):521-527.
[9] 王发现. 致密油水平井重复压裂技术及现场试验[J]. 大庆石油地质与开发, 2018, 37(4):171-174.
WANG Faxian. Re-fracturing technology and field test for horizontal wells in tight oil reservoirs[J]. Petroleum Geology & Development in Daqing, 2018, 37(4):171-174.
[10] 崔静, 高东伟, 毕文韬, 等. 页岩气井重复压裂选井评价模型研究及应用[J]. 岩性油气藏, 2018, 30(6):145-150.
CUI Jing, GAO Dongwei, BI Wentao, et al. Refracturing selection evaluation model for shale gas wells and its application[J]. Lithologic Reservoirs, 2018, 30(6):145-150.
[11] 王伟, 赵海峰, 季亮, 等. 韩城煤层重复压裂转向时机研究[J]. 煤矿安全, 2025, 56(1):26-33.
WANG Wei, ZHAO Haifeng, JI Liang, et al. Study on the best time of refracturing for Hancheng coal seam[J]. Safety in Coal Mines, 2025, 56(1):26-33.
[12] REN Jiawei, CHEN Junbin, LU Hongjun, et al. Optimizing refracturing models in tight oil reservoirs:An integrated workflow of geology and engineering based on seepage-stress real-time cross-coupling strategy[J]. SPE Journal, 2024, 29(11):6299-6311.
[13] TAVASSOLI S, YU Wei, JAVADPOUR F, et al. Well screen and optimal time of refracturing:A Barnett shale well[J]. Journal of Petroleum Engineering, 2013, 2013(1):1-10.
[14] ZHANG Xianmin, REN Jiawei, FENG Qihong, et al. Prediction of refracturing timing of horizontal wells in tight oil reservoirs based on an integrated learning algorithm[J]. Energies, 2021, 14(20):1-16.
[15] 郭建春, 陶亮, 曾凡辉. 致密油储集层水平井重复压裂时机优化:以松辽盆地白垩系青山口组为例[J]. 石油勘探与开发, 2019, 46(1):146-154.
GUO Jianchun, TAO Liang, ZENG Fanhui. Optimization of refracturing timing for horizontal wells in tight oil reservoirs:A case study of Cretaceous Qingshankou Formation,Songliao Basin,NE China[J]. Petroleum Exploration and Development, 2019, 46(1):146-154.
[16] 王强, 赵金洲, 胡永全, 等. 页岩气老井重复压裂时机优化方法[J]. 石油勘探与开发, 2024, 51(1):190-198.
WANG Qiang, ZHAO Jinzhou, HU Yongquan, et al. Optimization method of refracturing timing for old shale gas wells[J]. Petroleum Exploration and Development, 2024, 51(1):190-198.
[17] 于凤林, 刘敏, 侯继波, 等. 高含水后期油井重复压裂选井选层方法探讨[J]. 大庆石油地质与开发, 2005, 24(4):47-48.
YU Fenglin, LIU Min, HOU Jibo, et al. Discussion on well and layer selection methods for refracturing in high water-cut stage oil wells[J]. Petroleum Geology & Development in Daqing, 2005, 24(4):47-48.
[18] 张广清, 陈勉, 姚飞, 等. 各向异性地层重复压裂最优时机及影响因素分析[J]. 石油学报, 2008, 29(6):885-888.
ZHANG Guangqing, CHEN Mian, YAO Fei, et al. Study on optimal re-fracturing timing in anisotropic formation and its influencing factors[J]. Acta Petrolei Sinica, 2008, 29(6):885-888.
[19] 刘英君, 朱海燕, 唐煊赫, 等. 基于地质工程一体化的煤层气储层四维地应力演化模型及规律[J]. 天然气工业, 2022, 42(2):82-92.
LIU Yingjun, ZHU Haiyan, TANG Xuanhe, et al. Four-dimensional in-situ stress model of CBM reservoirs based on geology-engineering integration[J]. Natural Gas Industry, 2022, 42(2):82-92.
[20] 王俊超, 贾俊山, 李佳琦, 等. 老井开发对加密井水力压裂裂缝扩展的影响规律[J]. 科学技术与工程, 2022, 22(26):11356-11363.
WANG Junchao, JIA Junshan, LI Jiaqi, et al. Influences of development of old wells on fracture propagation from hydraulic fracturing of infill wells[J]. Science Technology and Enginee-ring, 2022, 22(26):11356-11363.
[21] 朱海燕, 宋宇家, 雷征东, 等. 致密油水平井注采储集层四维地应力演化规律:以鄂尔多斯盆地元 284 区块为例[J]. 石油勘探与开发, 2022, 49(1):136-147.
ZHU Haiyan, SONG Yujia, LEI Zhengdong, et al. 4D-stress evolution of tight sandstone reservoir during horizontal wells injection and production:A case study of Yuan 284 block,Ordos Basin,NW China[J]. Petroleum Exploration and Development, 2022, 49(1):136-147.
[22] 朱海燕, 宋宇家, 唐煊赫. 页岩气储层四维地应力演化及加密井复杂裂缝扩展研究进展[J]. 石油科学通报, 2021, 6(3):396-416.
ZHU Haiyan, SONG Yujia, TANG Xuanhe. Research progress on 4-dimensional stress evolution and complex fracture propagation of infill wells in shale gas reservoirs[J]. Petroleum Science Bulletin, 2021, 6(3):396-416.
[23] 吴佳, 赵卫卫, 刘钰晨, 等. 鄂尔多斯盆地延安地区三叠系长7页岩源储配置及油气富集规律[J]. 岩性油气藏, 2025, 37(1):170-181.
WU Jia, ZHAO Weiwei, LIU Yuchen, et al. Shale rock-reservoir collocation and hydrocarbon enrichment rule of Triassic Chang 7 member in Yan’an area,Ordos Basin[J]. Lithologic Reservoirs, 2025, 37(1):170-181.
[24] 梁锋, 曹哲. 鄂尔多斯盆地华池地区三叠系长7页岩油储层特征、形成环境及富集模式[J]. 岩性油气藏, 2025, 37(1):24-40.
LIANG Feng, CAO Zhe. Characteristics,formation environment and enrichment model of Triassic Chang 7 shale oil reservoir in Huachi area,Ordos Basin[J]. Lithologic Reservoirs, 2025, 37(1):24-40.
[25] 龙盛芳, 侯云超, 杨超, 等. 鄂尔多斯盆地西南部庆城地区三叠系长7段—长3段层序地层特征及演化规律[J]. 岩性油气藏, 2024, 36(1):145-156.
LONG Shengfang, HOU Yunchao, YANG Chao, et al. Sequence stratigraphy and evolution of Triassic Chang 7 to Chang 3 members in Qingcheng area,southwestern Ordos Basin[J]. Lithologic Reservoirs, 2024, 36(1):145-156.
[26] 文志刚, 罗雨舒, 刘江艳, 等. 陇东地区三叠系长7段页岩油储层孔隙结构特征及成因机制[J]. 岩性油气藏, 2022, 34(6):47-59.
WEN Zhigang, LUO Yushu, LIU Jiangyan, et al. Pore structure characteristics and genetic mechanism of Triassic Chang 7 shale oil reservoir in Longdong area[J]. Lithologic Reservoirs, 2022, 34(6):47-59.
[27] 屈雪峰, 何右安, 尤源, 等. 鄂尔多斯盆地庆城油田页岩油开发技术探索与实践[J]. 大庆石油地质与开发, 2024, 43(4):170-180.
QU Xuefeng, HE Youan, YOU Yuan, et al. Exploration and practice of shale oil development technology in Qingcheng Oilfield,Ordos Basin[J]. Petroleum Geology & Oilfield Development in Daqing, 2024, 43(4):170-180.
[28] 何永宏, 薛婷, 李桢, 等. 鄂尔多斯盆地长7页岩油开发技术实践:以庆城油田为例[J]. 石油勘探与开发, 2023, 50(6):1245-1258.
HE Yonghong, XUE Ting, LI Zhen, et al. Technical practice of Chang 7 shale oil development in the Ordos Basin:A case study of Qingcheng Oilfield[J]. Petroleum Exploration and Development, 2023, 50(6):1245-1258.
[29] JIANG Xiaowei, WANG Xusheng, WAN Li. Semi-empirical equations for the systematic decrease in permeability with depth in porous and fractured media[J]. Hydrogeology Journal, 2010, 18(4):839-850.
[30] 未志杰, 康晓东, 刘玉洋, 等. 煤层气藏全流固耦合数学模型[J]. 岩性油气藏, 2019, 31(2):151-158.
WEI Zhijie, KANG Xiaodong, LIU Yuyang, et al. A fully coupled fluid flow and geomechanics model for coalbed methane reservoir[J]. Lithologic Reservoirs, 2019, 31(2):151-158.
[31] 聂仁仕, 张雨晴, 周杰, 等. 考虑应力敏感及变井筒储集效应的水平井油气两相流试井模型[J]. 岩性油气藏, 2025, 37(4):184-191.
NIE Renshi, ZHANG Yuqing, ZHOU Jie, et al. Oil-gas two-phase flow well testing model of horizontal well considering stress sensitivity and changing wellbore storage effects[J]. Lithologic Reservoirs, 2025, 37(4):184-191.
[32] XU Yifei, CAVALCANTE FILHO J, YU Wei, et al. Discrete-fracture modeling of complex hydraulic-fracture geometries in reservoir simulators[J]. SPE Reservoir Evaluation & Engineering, 2017, 20(2):403-422.
[33] WANNIARACHCHI W A M, GAMAGE R P, PERERA M S A, et al. Investigation of depth and injection pressure effects on breakdown pressure and fracture permeability of shale reservoirs:An experimental study[J]. Applied Sciences, 2017, 7(7):664.
[34] WU Zhongwei, DONG Li, CUI Chuanzhi, et al. A numerical model for fractured horizontal well and production characteristics:Comprehensive consideration of the fracturing fluid injection and flowback[J]. Journal of Petroleum Science and Engineering, 2020, 187:106765.
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