Abstract:As an emerging hydraulic fracturing technology,cyclic injection has a promising application in glutenite reservoirs. Based on the true triaxial hydraulic fracturing system,the hydraulic fracturing experiments by continuous and cyclic injection are carried out under different stress conditions. By comparing the propagation characteristics,the propagation law of hydraulic fractures in glutenite under cyclic injection is clarified. The results show that the fracture propagation in glutenite is mainly controlled by two factors,including the stress difference and the structural characteristics,and the fracturing effect in glutenite can be improved significantly by cyclic injection. Under continuous injection,with the decrease of stress difference,the main controlling factor of fracture propagation will be changed from stress difference to gravel and natural fractures,and the glutenite will tend to produce scattered multiple fractures. There are limitations in enhancing the fracturing effect by pre-breakdown cyclic injection. Only under low stress difference(6 MPa),the breakdown pressure of glutenite can be decreased by 19%. By applying cyclic load to the fracture surface,the non-uniform deformation of the glutenite will be promoted by post-breakdown cyclic injection,and the influence of glutenite structure on the fracture propagation will be strengthened,thus the formation of multi-branch fractures will be promoted as well. At the same time,the limit of in-situ stress conditions can be broken by post-breakdown cyclic injection,the multi-fracture propagation in glutenite can still be formed under the condition of high stress difference(10 MPa).
徐常晫,张广清,彭 岩. 砂砾岩循环注液水力裂缝扩展规律研究[J]. 岩石力学与工程学报, 2024, 43(8): 1966-1977.
XU Changzhuo,ZHANG Guangqing,PENG Yan. Study on the propagation law of hydraulic fractures by cyclic injection in glutenite. , 2024, 43(8): 1966-1977.
[1] 刘向君,熊 健,梁利喜,等. 玛湖凹陷百口泉组砂砾岩储集层岩石力学特征与裂缝扩展机制[J]. 新疆石油地质,2018,39(1):83–91.(LIU Xiangjun,XIONG Jian,LIANG Lixi,et al. Rock mechanical characteristics and fracture propagation mechanism of sandy conglomerate reservoirs in Baikouquan Formation of Mahu Sag[J]. Xinjiang Petroleum Geology,2018,39(1):83–91.(in Chinese))
[2] 王 乔,宋立新,韩亚杰,等. 辽河西部凹陷雷家地区古近系沙三段沉积体系及层序地层[J]. 岩性油气藏,2021,33(6):102–113. (WANG Qiao,SONG Lixin,HAN Yajie,et al. Depositional system and sequence stratigraphy of the third member of Paleogene Shahejie Formation in Leijia area,Western Liaohe Depression[J]. Lithologic Reservoirs,2021,33(6):102–113.(in Chinese))
[3] 闫建平,言 语,李尊芝,等. 砂砾岩储层物性演化及影响因素研究——以东营凹陷北部陡坡带为例[J]. 岩性油气藏,2016,28(2):1–6.(YAN Jianping,YAN Yu,LI Zunzhi,et al. Physical property evolution of glutenite reservoir and its influencing factors:A case study from northern steep slope zone in Dongying Sag[J]. Lithologic Reservoirs,2016,28(2):1–6.(in Chinese))
[4] 孙 靖,尤新才,薛晶晶,等. 准噶尔盆地致密粗粒储层发育特征及影响因素:以玛湖地区二叠系致密砾岩储层为例[J]. 地质科学,2022,57(3):671–686.(SUN Jing,YOU Xincai,XUE Jingjing,et al. Development characteristics and influence factors of tight coarse grained reservoirs of Junggar Basin:A case study from tight conglomerate reservoir of Permian in Mahu area[J]. Earth Science,2022,57(3):671–686.(in Chinese))
[5] 曹 炜,鲜成钢,吴宝成,等. 玛湖致密砾岩油藏水平井生产动态分析及产能预测——以玛131小井距立体开发平台为例[J]. 新疆石油地质,2022,43(4):440–449.(CAO Wei,XIAN Chenggang,WU Baocheng,et al. Production performance analysis and productivity prediction of horizontal wells in Mahu Tight Conglomerate Reservoirs:A case of Ma 131 Dense?Spacing 3D development pad[J]. Xinjiang Petroleum Geology,2022,43(4):440–449.(in Chinese))
[6] 李连崇,李 根,孟庆民,等. 砂砾岩水力压裂裂缝扩展规律的数值模拟分析[J]. 岩土力学,2013,34(5):1 501–1 507.(LI Lianchong,LI Gen,MENG Qingmin,et al. Numerical simulation of propagation of hydraulic fractures in glutenite formation[J]. Rock and Soil Mechanics,2013,34(5):1 501–1 507.(in Chinese))
[7] 张家伟,刘向君,熊 健,等. 基于离散元法的砾岩水力压裂裂缝扩展规律及主控因素[J]. 大庆石油地质与开发,2023,42(3):48–57.(ZHANG Jiawei,LIU Xiangjun,XIONG Jian,et al. Fracture propagation law and main controlling factors of conglomerate hydraulic fracturing based on discrete element method[J]. Petroleum Geology and Oilfield Development in Daqing,2023,42(3):48–57.(in Chinese))
[8] LIU J,GE H,ZHANG Z,et al. Influence of mechanical contrast between the matrix and gravel on fracture propagation of glutenite[J]. Journal of Petroleum Science and Engineering,2022,208:109639.
[9] LUO S,GE H,WANG J,et al. Numerical simulation study on the crack propagation of conglomerate[J]. Royal Society Open Science,2021,8(7):202178.
[10] 刘鹏宇,蒋庆平,申颍浩,等. 玛湖凹陷砾岩裂缝扩展数值模拟[J]. 新疆石油地质,2022,43(2):227–234.(LIU Pengyu,JIANG Qingping,SHEN Yinghao,et al. Numerical Simulation on Fracture Propagation in Conglomerate in Mahu Sag[J]. Xinjiang Petroleum Geology,2022,43(2):227–234.(in Chinese))
[11] 许江文,李建民,邬元月,等. 玛湖致密砾岩油藏水平井体积压裂技术探索与实践[J]. 中国石油勘探,2019,24(2):241–249.(XU Jiangwen,LI Jianmin,WU Yuanyue,et al. Exploration and practice of volume fracturing technology in horizontal well of Mahu tight conglomerate reservoirs[J]. China Petroleum Exploration,2019,24(2):241–249.(in Chinese))
[12] 李 宁,张士诚,马新仿,等. 砂砾岩储层水力裂缝扩展规律试验研究[J]. 岩石力学与工程学报,2017,36(10):2 383–2 392.(LI Ning,ZHANG Shicheng,MA Xinfang,et al. Experimental study on the propagation mechanism of hydraulic fracture in glutenite formations[J]. Chinese Journal of Rock Mechanics and Engineering,2017,36(10):2 383–2 392.(in Chinese))
[13] HULSE D S. Fracturing process with superimposed cyclic pressure[P]. U.S.:2915122,1959–12–1.
[14] ZANG A,YOON J S,STEPHANSSON O,et al. Fatigue hydraulic fracturing by cyclic reservoir treatment enhances permeability and reduces induced seismicity[J]. Geophysical Journal International,2013,195(2):1 282–1 287.
[15] YOON J S,ZIMMERMANN G,ZANG A. Discrete element modeling of cyclic rate fluid injection at multiple locations in naturally fractured reservoirs[J]. International Journal of Rock Mechanics and Mining Sciences,2015,74:15–23.
[16] ZANG A,STEPHANSSON O,STENBERG L,et al. Hydraulic fracture monitoring in hard rock at 410 m depth with an advanced fluid-injection protocol and extensive sensor array[J]. Geophysical Journal International,2017,208(2):790–813.
[17] ZHUANG L,KIM K Y,JUNG S G,et al. Cyclic hydraulic fracturing of pocheon granite cores and its impact on breakdown pressure,acoustic emission amplitudes and injectivity[J]. International Journal of Rock Mechanics and Mining Sciences,2019,122:104065.
[18] PATEL S M,SONDERGELD C H,RAI C S. Laboratory studies of hydraulic fracturing by cyclic injection[J]. International Journal of Rock Mechanics and Mining Sciences,2017,95:8–15.
[19] ZHOU Z L,ZHANG G Q,DONG H R,et al. Creating a network of hydraulic fractures by cyclic pumping[J]. International Journal of Rock Mechanics and Mining Sciences,2017,97:52–63.
[20] DIAZ M B,KIM K Y,JUNG S G. Effect of frequency during cyclic hydraulic fracturing and the process of fracture development in laboratory experiments[J]. International Journal of Rock Mechanics and Mining Sciences,2020,134:104474.
[21] NIE Y,ZHANG G,WEN J,et al. Cyclic injection to reduce hydraulic fracture surface roughness in glutenite reservoirs[J]. International Journal of Rock Mechanics and Mining Sciences,2021,142:104740.
[22] 范铁刚. 煤层水力压裂网络裂缝形成机制研究[博士学位论文][D]. 北京:中国石油大学(北京),2015.(FAN Tiegang. Formation mechanism investigation on hydraulic fracture network of coal seams[Ph. D. Thesis][D]. Beijing:China University of Petroleum (Beijing),2015.(in Chinese))
[23] 张广清,周大伟,窦金明,等. 天然裂缝群与地应力差作用下水力裂缝扩展试验[J]. 中国石油大学学报:自然科学版,2019,43(5):157–162.(ZHANG Guangqing,ZHOU Dawei,DOU Jinming,et al. Experiments on hydraulic fracture propagation under action of natural fractures and crustal stress difference[J]. Journal of China University of Petroleum:Natural Science,2019,43(5):157–162.(in Chinese))
[24] 程正华,艾 池,张 军,等. 胶结型天然裂缝对水力压裂裂缝延伸规律的影响[J]. 新疆石油地质,2022,43(4):433–439.(CHENG Zhenghua,AI Chi,ZHANG Jun,et al. Influences of cemented natural fractures on propagation of hydraulic fractures[J]. Xinjiang Petroleum Geology,2022,43(4):433–439.(in Chinese))
[25] ZHUANG L,KIM K Y,JUNG S G,et al. Laboratory study on cyclic hydraulic fracturing of Pocheon granite in Korea[C]// 50th US Rock Mechanics/geomechanics Symposium. OnePetro:[s. n.],2016.
[26] JUNG S G,DIAZ M B,KIM K Y,et al. Fatigue behavior of granite subjected to cyclic hydraulic fracturing and observations on pressure for fracture growth[J]. Rock Mechanics and Rock Engineering,2021,54(10):5 207–5 220.
[27] LI N,XIE H,HU J,et al. A critical review of the experimental and theoretical research on cyclic hydraulic fracturing for geothermal reservoir stimulation[J]. Geomechanics and Geophysics for Geo-energy and Geo-resources,2022,8:1–19.