特低渗透油藏注水诱导动态裂缝实验及数值模拟

梁卫卫; 党海龙; 刘滨; 张天龙; 王小锋; 侯玢池; 崔鹏兴; 王谦; 张凤远

doi:10.11781/sysydz202303566

特低渗透油藏注水诱导动态裂缝实验及数值模拟

doi: 10.11781/sysydz202303566

梁卫卫^{1, 2,},
党海龙^{1, 2, ,},
刘滨^{1, 2},
张天龙^{1, 2},
王小锋^{1, 2},
侯玢池^{1, 2},
崔鹏兴^{1, 2},
王谦^{1, 2},
张凤远³

1.
陕西延长石油(集团)有限责任公司研究院, 西安 710065
2.
陕西省特低渗透油气田勘探与开发工程技术研究中心, 西安 710065
3.
中国石油大学(北京) 石油工程学院, 北京 102249

基金项目:

陕西省科技统筹创新工程计划项目“延长难采储量有效动用开发技术研究” 2016KTCL01-12

详细信息

作者简介:
梁卫卫(1987—)，男，硕士，高级工程师，从事油藏地质建模及数值模拟研究。E-mail: 510741536@qq.com

通讯作者:
党海龙(1971—)，男，博士，教授级高级工程师，从事低渗透油藏开发理论与技术研究工作。E-mail: danghl@yeah.net

中图分类号: TE348
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- 被引次数: 0
出版历程
- 收稿日期: 2022-11-29
- 修回日期: 2023-04-02
- 刊出日期: 2023-05-28

Experiment and numerical simulation of water injection induced dynamic fractures in ultra-low permeability reservoirs

LIANG Weiwei^{1, 2
,},
DANG Hailong^{1, 2
, ,},
LIU Bin^{1, 2},
ZHANG Tianlong^{1, 2},
WANG Xiaofeng^{1, 2},
HOU Binchi^{1, 2},
CUI Pengxing^{1, 2},
WANG Qian^{1, 2},
ZHANG Fengyuan³

1.
Research Institute of Shaanxi Yanchang Petroleum (Group) Co., Ltd., Xi'an, Shaanxi, 710065, China
2.
Ultra-low Permeability Oil and Gas Exploration and Development Engineering Research Center of Shaanxi Province, Xi'an, Shaanxi, 710065, China
3.
School of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China

摘要

摘要: 为了进一步明确特低渗透油藏注水诱导动态裂缝形成机理及其对特低渗透油藏注水开发的影响，基于注水诱导动态裂缝室内实验，阐述了注水诱导动态裂缝成因机理及延伸过程，建立了注水诱导动态裂缝数值表征方法并进行了相对应的油藏数值模拟研究。注水诱导动态裂缝按照成因主要分为天然闭合型、人工压裂诱导型和超储层破裂压力型3类。注水诱导动态裂缝生长机理主要为注入压力与岩石破裂压力或裂缝延伸压力的反复作用促使岩石发育裂缝或使已存在的裂缝不断延伸。改进的注水诱导动态裂缝实验表明，注入压力呈现反复的“升—降”特征，且注入压力是岩石产生注水诱导动态裂缝的主控参数。注水诱导动态裂缝数值模拟结果也验证了注入井井底压力呈现周期性“憋压上升—起裂下降”趋势。诱导动态裂缝产生后，裂缝体系内的压力和饱和度场是随着动态裂缝的开启和延伸而动态变化的，且沿裂缝体系变化明显，裂缝系统两侧波及范围小。
- 注水诱导动态裂缝 /
- 成因机理 /
- 室内实验 /
- 诱导裂缝数值表征 /
- 油藏数值模拟 /
- 特低渗透油藏
Abstract: In order to further clarify the mechanism of water injection induced dynamic fractures in ultra-low permeability reservoirs and its influence on water injection development in ultra-low permeability reservoirs, the genetic mechanism and propagation process of dynamic fractures induced by water injection were expounded based on the laboratory experiments of water injection induced dynamic fractures. A numerical characterization method of water injection induced dynamic fractures was established, and the corresponding reservoir numerical simulation was researched. The results indicate that the water injection induced dynamic fractures include natural closure type, artificial fracturing induced type and super reservoir breakdown pressure type. The main growth mechanism of water injection induced dynamic fractures was that the continuous extension of the fractures developed in rocks or the existing fractures through repeated action of injection pressure and rock breakdown pressure or fracture propagation pressure. The improved water injection induced dynamic fracture experiment shows that the injection pressure presents the characteristics of repeated "up and down", and the injection pressure is the main controlling parameter for the rock to generate water injection induced dynamic fractures. The numerical simulation results verify that the bottom hole pressure of the injection well shows a periodic trend of "pressure-build rise and crack initiation drop". After the dynamic fracture was induced, the pressure and saturation fields in the fracture system change dynamically with the opening and extension of the dynamic fracture and the changes are mainly obvious along the fracture system, and the influence range on both sides of the fracture system is small.
- water injection induced dynamic fracture /
- genetic mechanism /
- laboratory experiment /
- numerical characterization of induced fracture /
- reservoir numerical simulation /
- ultra-low permeability reservoir

HTML全文

图 1 鄂尔多斯盆地延长油田西部油区岩样注入压力与注入速度之间的关系

Figure 1. Relationship between injection pressure and rate of rock samples in western oil region of Yanchang oilfield, Ordos Basin

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图 2 鄂尔多斯盆地延长油田西部油区岩样注入压力与注入速度之间的关系曲线

Figure 2. Relationship between injection pressure and rate of rock samples in western oil region of Yanchang oilfield, Ordos Basin

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图 3 鄂尔多斯盆地延长油田西部油区岩心注入PV数与注入压力的关系

Figure 3. Relationship between injection PV number and pressure of rock samples in western oil region of Yanchang oilfield, Ordos Basin

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图 4 鄂尔多斯盆地延长油田西部油区长6油藏注水指示曲线

Figure 4. Water injection index curves of Chang-6 reservoir in western oil region of Yanchang oilfield, Ordos Basin

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图 5 考虑注水诱导动态裂缝的单一注采连线模型

Figure 5. Single injection-production connection model considering water injection induced dynamic fractures

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图 6 低渗透油藏注水诱导动态裂缝扩展模型

Figure 6. Propagation model of water injection induced dynamic fractures in ultra-low permeability reservoirs

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图 7 鄂尔多斯盆地志丹地区Z147-7井组注入井井底压力特征

Figure 7. Bottom hole pressure characteristics of injection well in Z147-7 well group, Zhidan area, Ordos Basin

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图 8 鄂尔多斯盆地志丹地区Z147-7井组注入井不同注水时刻压力场

Figure 8. Pressure field diagram of injection well at different water injection times of Z147-7 well group, Zhidan area, Ordos Basin

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图 9 鄂尔多斯盆地志丹地区Z147-7井组注入井不同注水时刻饱和度场

Figure 9. Saturation field diagram of injection well at different water injection times of Z147-7 well group, Zhidan area, Ordos Basin

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表 1 鄂尔多斯盆地延长油田西部油区三叠系延长组岩心基础实验数据

Table 1. Core basic experimental data of Triassic Yanchang Formation in western oil region of Yanchang oilfield, Ordos Basin

油层组	深度/m	样品编号	样品长度/cm	样品体积/cm³	孔隙体积/cm³	孔隙度/%	渗透率/10^-3μm²	储层物性
长6	1 264.8	Z1	7.03	32.69	4.81	14.7	0.56	低孔、超低渗
	1 299.3	Z2	6.85	23.27	1.86	8.0	0.32	特低孔、超低渗
	1 529.2	Z3	7.04	32.49	3.60	11.1	0.36	低孔、超低渗
长8	2 492.6	D1	7.04	31.92	3.58	11.2	0.18	低孔、超低渗
	2 493.1	D2	7.03	31.83	3.62	11.4	0.16	低孔、超低渗
	2 424.1	D3	7.04	32.24	3.03	9.4	0.09	特低孔、超低渗
长9	2 218.8	W1	7.02	32.67	4.31	13.2	0.18	低孔、超低渗
	2 080.3	W2	6.18	28.92	3.88	13.4	0.15	低孔、超低渗
	2 080.6	W3	3.73	19.49	2.65	13.6	0.12	低孔、超低渗

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表 2 鄂尔多斯盆地延长油田西部油区岩心注水诱导动态裂缝起裂次数与累计注入PV数统计

Table 2. Statistics of initiation times and cumulative injection PV number of water injection induced dynamic fractures in western oil region of Yanchang oilfield, Ordos Basin

岩心编号	起裂次数	累计注入体积/cm³	累计注入PV数
Z2	1	2.8	1.51
	2	4.6	2.47
	3	9.8	5.27
W1	1	6.3	1.45
W2	1	3.0	0.77

下载: 导出CSV

参考文献(30)

[1]	范天一, 吴淑红, 李巧云, 等. 注水诱导动态裂缝影响下低渗透油藏数值模拟[J]. 特种油气藏, 2015, 22(3): 85-88. doi: 10.3969/j.issn.1006-6535.2015.03.021 FAN Tianyi, WU Shuhong, LI Qiaoyun, et al. Low permeability reservoir numerical simulation by considering water-injection induced dynamic fracture[J]. Special Oil & Gas Reservoirs, 2015, 22(3): 85-88. doi: 10.3969/j.issn.1006-6535.2015.03.021
[2]	王卓, 赵靖舟, 孟选刚, 等. 鄂尔多斯盆地东南部柴上塬区三叠系延长组长6致密油成藏主控因素及富集规律[J]. 石油实验地质, 2022, 44(2): 251-261. doi: 10.11781/sysydz202202251 WANG Zhuo, ZHAO Jingzhou, MENG Xuangang, et al. Key controlling factors and enrichment mechanisms of tight reservoirs in 6th member of Triassic Yanchang Formation, Chaishangyuan area, southeastern Ordos Basin[J]. Petroleum Geology & Experiment, 2022, 44(2): 251-261. doi: 10.11781/sysydz202202251
[3]	苑志旺, 杨莉, 杨宝泉, 等. 深海浊积砂岩油田高效注水策略及实践[J]. 西南石油大学学报(自然科学版), 2021, 43(2): 117-127. https://www.cnki.com.cn/Article/CJFDTOTAL-XNSY202102013.htm YUAN Zhiwang, YANG Li, YANG Baoquan, et al. Strategy and practice of high efficient water injection in deep sea turbidite sandstone oilfield[J]. Journal of Southwest Petroleum University (Science & Technology Edition), 2021, 43(2): 117-127. https://www.cnki.com.cn/Article/CJFDTOTAL-XNSY202102013.htm
[4]	周晋冲, 张彬, 雷征东, 等. 低渗透油藏不稳定注水岩心实验及增油机理[J]. 新疆石油地质, 2022, 43(4): 491-495. https://www.cnki.com.cn/Article/CJFDTOTAL-XJSD202204017.htm ZHOU Jinchong, ZHANG Bin, LEI Zhengdong, et al. Core experiment and stimulation mechanism of unstable waterflooding in low permeability reservoirs[J]. Xinjiang Petroleum Geology, 2022, 43(4): 491-495. https://www.cnki.com.cn/Article/CJFDTOTAL-XJSD202204017.htm
[5]	白青林, 束青林, 焦红岩, 等. 调节带低级序断层特征及其对注水开发的影响[J]. 断块油气田, 2021, 28(5): 671-676. https://www.cnki.com.cn/Article/CJFDTOTAL-DKYT202105019.htm BAI Qinglin, SHU Qinglin, JIAO Hongyan, et al. The low-grade faults characteristics and its influence on water-flooding development in accommodation zone[J]. Fault-Block Oil and Gas Field, 2021, 28(5): 671-676. https://www.cnki.com.cn/Article/CJFDTOTAL-DKYT202105019.htm
[6]	刘传喜, 方文超, 秦学杰. 非常规油气藏压裂水平井动态缝网模拟方法及应用[J]. 石油与天然气地质, 2022, 43(3): 696-702. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT202203017.htm LIU Chuanxi, FANG Wenchao, QIN Xuejie. Simulation of dynamic fracture network in fractured horizontal well for unconventional reservoirs: theory and application[J]. Oil & Gas Geology, 2022, 43(3): 696-702. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT202203017.htm
[7]	汪洋, 程时清, 秦佳正, 等. 超低渗透油藏注水诱导动态裂缝开发理论及实践[J]. 中国科学: 技术科学, 2022, 52(4): 613-626. https://www.cnki.com.cn/Article/CJFDTOTAL-JEXK202204007.htm WANG Yang, CHENG Shiqing, QIN Jiazheng, et al. Development theory and practice of water injection induced fractures in ultra-low permeability reservoirs[J]. Scientia Sinica Technologica, 2022, 52(4): 613-626. https://www.cnki.com.cn/Article/CJFDTOTAL-JEXK202204007.htm
[8]	WANG Yang, CHENG Shiqing, ZHANG Kaidi, et al. A comprehensive work flow to characterize waterflood-induced fractures by integrating real-time monitoring, formation test, and dynamic production analysis applied to Changqing oil field, China[J]. SPE Reservoir Evaluation & Engineering, 2019, 22(2): 692-708.
[9]	WANG Youjing, SONG Xinmin. Comprehensive characterization integrating static and dynamic data for dynamic fractures in ultra-low permeability reservoirs: a case study of the Chang 6 reservoir of the Triassic Yanchang Formation in the Ordos Basin, China[J]. Minerals, 2022, 12(10): 1277.
[10]	王友净, 宋新民, 田昌炳, 等. 动态裂缝是特低渗透油藏注水开发中出现的新的开发地质属性[J]. 石油勘探与开发, 2015, 42(2): 222-228. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201502013.htm WANG Youjing, SONG Xinmin, TIAN Bingchang, et al. Dynamic fractures are an emerging new development geological attribute in water-flooding development of ultra-low permeability reservoirs[J]. Petroleum Exploration and Development, 2015, 42(2): 222-228. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201502013.htm
[11]	WANG Jinfang, ZHENG Xingfan, WANG Zhengmao, et al. Integrated approach to identify and control the water-injection induced fractures in the low-permeability reservoir[C]// SPE Annual Caspian Technical Conference and Exhibition. Astana, Kazakhstan: SPE, 2018.
[12]	谢景彬, 龙国清, 田昌炳, 等. 特低渗透砂岩油藏动态裂缝成因及对注水开发的影响: 以安塞油田王窑区长6油组为例[J]. 油气地质与采收率, 2015, 22(3): 106-110. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCS201503019.htm XIE Jingbin, LONG Guoqing, TIAN Bingchang, et al. Genetic mechanism of dynamic fracture and its influence on water flooding deve-lopment in extra-low permeability sandstone reservoir: a case of Chang 6 member in Wangyao area, Ansai oilfield[J]. Petroleum Geology and Recovery Efficiency, 2015, 22(3): 106-110. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCS201503019.htm
[13]	赵向原, 曾联波, 靳宝光, 等. 裂缝性低渗透砂岩油藏合理注水压力: 以鄂尔多斯盆地安塞油田王窑区为例[J]. 石油与天然气地质, 2015, 36(5): 855-861. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201505021.htm ZHAO Xiangyuan, ZENG Lianbo, JIN Baoguang, et al. Discussion on optimal injection pressure of fractured low-permeability sandstone reservoirs: a case study from Wangyao block in Ansai oilfield, Ordos Basin[J]. Oil & Gas Geology, 2015, 36(5): 855-861. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201505021.htm
[14]	曾联波, 赵向原, 朱圣举, 等. 低渗透油藏注水诱导裂缝及其开发意义[J]. 石油科学通报, 2017, 2(3): 336-343. https://www.cnki.com.cn/Article/CJFDTOTAL-SYKE201703002.htm ZENG Lianbo, ZHAO Xiangyuan, ZHU Shengju, et al. Waterflood-induced fractures and its significance for development of low-permeability sandstone oil reservoirs[J]. Petroleum Science Bulletin, 2017, 2(3): 336-343. https://www.cnki.com.cn/Article/CJFDTOTAL-SYKE201703002.htm
[15]	赵向原, 曾联波, 胡向阳, 等. 低渗透砂岩油藏注水诱导裂缝特征及其识别方法: 以鄂尔多斯盆地安塞油田W区长6油藏为例[J]. 石油与天然气地质, 2017, 38(6): 1187-1197. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201706022.htm ZHAO Xiangyuan, ZENG Lianbo, HU Xiangyang, et al. Characteristics of waterflood induced fracture in low-permeability sandstone reservoirs and its identification methods: a case study from Chang 6 reservoir in W area in Ansai oilfield, Ordos Basin[J]. Oil & Gas Geology, 2017, 38(6): 1187-1197. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201706022.htm
[16]	赵向原, 曾联波, 靳宝光, 等. 低渗透油藏注水诱导裂缝特征及形成机理: 以鄂尔多斯盆地安塞油田长6油藏为例[J]. 石油与天然气地质, 2018, 39(4): 696-705. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201804008.htm ZHAO Xiangyuan, ZENG Lianbo, JIN Baoguang, et al. Characteristics and formation mechanisms of waterflood induced fractures in low-permeability reservoirs: a case study from Chang 6 reservoir in Ansai oilfield, Ordos Basin[J]. Oil & Gas Geology, 2018, 39(4): 696-705. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201804008.htm
[17]	赵向原, 吕文雅, 王策, 等. 低渗透砂岩油藏注水诱导裂缝发育的主控因素: 以鄂尔多斯盆地安塞油田W区长6油藏为例[J]. 石油与天然气地质, 2020, 41(3): 586-595. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT202003015.htm ZHAO Xiangyuan, LV Wenya, WANG Ce, et al. Major factors controlling waterflooding-induced fracture development in low-permeability reservoirs: a case study of Chang 6 reservoir in W block in Ansai oilfield, Ordos Basin[J]. Oil & Gas Geology, 2020, 41(3): 586-595. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT202003015.htm
[18]	王文环, 彭缓缓, 李光泉, 等. 长庆特低渗透油藏注水动态裂缝及井网加密调整模式研究[J]. 石油钻探技术, 2015, 43(1): 106-110. https://www.cnki.com.cn/Article/CJFDTOTAL-SYZT201501021.htm WANG Wenhuan, PENG Huanhuan, LI Guangquan, et al. Research on water flooding dynamic fractures to optimize infill drilling spacing in ultra-low permeability reservoirs, Changqing oilfield[J]. Petroleum Drilling Techniques, 2015, 43(1): 106-110. https://www.cnki.com.cn/Article/CJFDTOTAL-SYZT201501021.htm
[19]	王文环, 彭缓缓, 李光泉, 等. 大庆低渗透油藏注水动态裂缝开启机理及有效调整对策[J]. 石油与天然气地质, 2015, 36(5): 842-847. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201505019.htm WANG Wenhuan, PENG Huanhuan, LI Guangquan, et al. Opening mechanism of dynamic fractures caused by water injection and effective adjustments in low permeability reservoirs, Daqing oilfield in Songliao Basin[J]. Oil & Gas Geology, 2015, 36(5): 842-847. https://www.cnki.com.cn/Article/CJFDTOTAL-SYYT201505019.htm
[20]	彭缓缓, 王文环, 吕文峰, 等. 考虑动态裂缝的特低渗透油藏渗流模型[J]. 断块油气田, 2016, 23(5): 630-633. https://www.cnki.com.cn/Article/CJFDTOTAL-DKYT201605019.htm PENG Huanhuan, WANG Wenhuan, LV Wenfeng, et al. Seepage model of ultra-low permeability reservoir considering dynamic fracture[J]. Fault-Block Oil & Gas Field, 2016, 23(5): 630-633. https://www.cnki.com.cn/Article/CJFDTOTAL-DKYT201605019.htm
[21]	范天一, 宋新民, 吴淑红, 等. 低渗透油藏水驱动态裂缝数学模型及数值模拟[J]. 石油勘探与开发, 2015, 42(4): 496-501. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201504013.htm FAN Tianyi, SONG Xinmin, WU Shuhong, et al. A mathematical model and numerical simulation of waterflood induced dynamic fractures of low permeability reservoirs[J]. Pertroleum Exploration and Development, 2015, 42(4): 496-501. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201504013.htm
[22]	JIANG Le, GAO Peng, LIU Jie, et al. Simulation and optimization of dynamic fracture parameters for an inverted square nine-spot well pattern in tight fractured oil reservoirs[J]. Geofluids, 2020, 2020: 8883803.
[23]	吴义志, 马栋, 张凯迪, 等. 致密油藏动态裂缝影响下水驱开发数值模拟[J]. 科学技术与工程, 2020, 20(27): 11059-11066. https://www.cnki.com.cn/Article/CJFDTOTAL-KXJS202027012.htm WU Yizhi, MA Dong, ZHANG Kaidi, et al. Reservoir simulation of waterflooding under the influence of dynamic fractures for tight oil reservoir[J]. Science Technology and Engineering, 2020, 20(27): 11059-11066. https://www.cnki.com.cn/Article/CJFDTOTAL-KXJS202027012.htm
[24]	高见. 动态裂缝对地层压力分布规律影响规律研究[D]. 大庆: 东北石油大学, 2017. GAO Jian. Study on the influence of dynamic fracture on formation pressure distribution[D]. Daqing: Northeast Petroleum University, 2017.
[25]	高毅, 林利飞, 尹帅, 等. 致密油储层地应力特征及其对物性的影响: 以鄂尔多斯盆地上三叠统延长组为例[J]. 石油实验地质, 2021, 43(2): 250-258. doi: 10.11781/sysydz202102250 GAO Yi, LIN Lifei, YIN Shuai, et al. Characteristics of in situ stress of tight oil reservoirs and its influence on petrophysical properties: a case study of Upper Triassic Yanchang Formation in Ordos Basin[J]. Petroleum Geology & Experiment, 2021, 43(2): 250-258. doi: 10.11781/sysydz202102250
[26]	刘丹. 注水诱导裂缝井试井特征研究[D]. 成都: 西南石油大学, 2019. LIU Dan. Study on the characteristics of waterflood induced fracture well test[D]. Chengdu: Southwest Petroleum University, 2019.
[27]	杨波. 储层裂缝动态变化规律及机理研究[D]. 成都: 西南石油大学, 2009. YANG Bo. Regularity and mechanism research on the dynamic change of reservoir fractures[D]. Chengdu: Southwest Petroleum University, 2009.
[28]	曾庆桥, 张亮, 刘萍, 等. 基于井间连通性的致密油藏注水井动态裂缝研究[J]. 断块油气田, 2022, 29(3): 383-389. https://www.cnki.com.cn/Article/CJFDTOTAL-DKYT202203016.htm ZENG Qingqiao, ZHANG Liang, LIU Ping, et al. Study on dynamic fracture of injection well based on inter-well connectivity in tight oil reservoir[J]. Fault-Block Oil and Gas Field, 2022, 29(3): 383-389. https://www.cnki.com.cn/Article/CJFDTOTAL-DKYT202203016.htm
[29]	王强, 赵金洲, 胡永全, 等. 页岩水力裂缝网络形态及激活机制研究[J]. 西南石油大学学报(自然科学版), 2022, 44(6): 71-86. https://www.cnki.com.cn/Article/CJFDTOTAL-XNSY202206008.htm WANG Qiang, ZHAO Jinzhou, HU Yongquan, et al. Investigation on the morphology and activation mechanism of hydraulic fracture network in shale[J]. Journal of Southwest Petroleum University (Science & Technology Edition), 2022, 44(6): 71-86. https://www.cnki.com.cn/Article/CJFDTOTAL-XNSY202206008.htm
[30]	何强, 李凤霞, 史爱萍, 等. 基于三维CT重构的油页岩复杂水力裂缝网络分形表征[J]. 油气地质与采收率, 2021, 28(5): 116-123. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCS202105015.htm HE Qiang, LI Fengxia, SHI Aiping, et al. Fractal characterization of complex hydraulic fracture networks of oil shale via 3D CT reconstruction[J]. Petroleum Geology and Recovery Efficiency, 2021, 28(5): 116-123. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCS202105015.htm