Numerical simulation of mesoscopic deformation and failure for glutenite in Triassic Baikouquan Formation, Junggar Basin
-
摘要: 我国西部准噶尔盆地三叠系百口泉组砂砾岩致密油资源丰富。因砂砾岩储层中含有众多成分及强度大小不一的砾石，导致砂砾岩力学特征受砾石的形状、尺寸及物性影响较大，进而影响砂砾岩油藏的压裂裂缝复杂程度和压裂改造效果。鉴于此，针对准噶尔盆地百口泉组砂砾岩储层特征，建立了随机不规则多边形砾石的生成方法，并基于颗粒离散元法建立了砂砾岩力学数值模型，研究了典型砾石含量和分布对砂砾岩细观力学特征的影响机理。砂砾岩变形破坏数值模拟结果表明：低强度砾石对裂缝延伸的屏蔽作用较弱，裂缝大多呈“穿砾”模式，而高强度砾石对裂缝的屏蔽作用较强，裂缝更多呈“绕砾”模式；围压增加，岩石抗压强度明显增加，峰值应变能及滑移能也呈线性增加，且应变能增长显著；含不同砾石组合的砂砾岩储层中，剪切微裂缝数量随围压的增加而增加，且具有线性特征关系，高围压下含高强度砾石的砂砾岩具有更显著的塑性及延性特征，且存在明显的二次破坏现象；随低强度砾石的减少或高强度砾石的增加，砂砾岩的弹性模量增大，且抵抗变形能力增强，而不同砾石组合情况下，围压对砂砾岩弹性模量的影响较小；砂砾岩宏观破坏带的形成发育过程很大程度受控于内部细观结构，且受围压、砾石类型(力学强度)等的影响较大。Abstract: The Triassic Baikouquan Formation glutenite in the Junggar Basin of western China is rich in tight oil resources. Due to the presence of gravels with varying composition and strength in the glutenite, the mechanical characteristics of the glutenite are significantly affected by the shape, size, and physical properties of the gravels, which in turn affects the fracture complexity and fracturing reconstruction effectiveness of the glutenite reservoirs. In view of this, a method for generating random irregular polygonal gravels was established based on the reservoir characteristics of Baikouquan Formation, Junggar Basin. A mechanical numerical model of the glutenite was created based on particle discrete element method to study the influence mechanism of typical gravel content and distribu-tion on the meso-mechanical characteristics of glutenite. The results show that low-strength gravels have a weak shielding effect on fracture propagation, with most cracks exhibiting a "penetrating gravel" pattern. In contrast, high-strength gravels exhibit a stronger shielding effect, leading to more "bypass gravel" fracture patterns. With increased confining pressure, the compressive strength of the rock significantly increases, along with peak strain energy and slip energy, both showing a linear increase with strain energy being particularly pronounced. In glutenite reservoirs with different gravel combinations, there is a strong linear relationship between the number of shear microcracks and the confining pressure. The glutenite reservoirs with high confining pressure and high-strength gravels exhibit more obvious plastic and ductile characteristics, along with evident secondary failure phenomena. With the decrease of low-strength gravels or the increase of high-strength gravels, the elastic modulus of the glutenite increases, enhancing its resistance to deformation. However, the influence of confining pressure on the elastic modulus of glutenite is minimal across different gravel combinations. The formation and development of macroscopic failure zones in glutenite are largely controlled by the internal meso-structure and are greatly affected by confining pressure and gravel type (mechanical strength).
-
图 2 准噶尔盆地三叠系百口泉组砂砾岩照片
Figure 2. Photograph of glutenite from Triassic Baikouquan Formation, Junggar Basin
图 3 准噶尔盆地三叠系百口泉组砂砾岩三轴(围压40 MPa)压缩模拟结果
Figure 3. Simulation results of glutenite triaxial compression (confining pressure 40 MPa) in Triassic Baikouquan Formation, Junggar Basin
图 4 不同围压下砂砾岩三轴压缩破坏形态
Figure 4. Triaxial compression failure patterns of glutenite under different confining pressures
图 5 不同围压微裂缝数量及能量曲线的演化过程
Figure 5. Evolution of number and energy curves of microcracks under different confining pressures
图 6 不同围压砂砾岩轴向压缩模拟结果对比
Figure 6. Comparison of axial compression simulation results of glutenite under different confining pressures
图 7 不同围压下不同砾石比例砂砾岩三轴压缩破坏形态
Figure 7. Failure patterns of glutenite with different gravel ratios under different confining pressures in triaxial compression
图 8 不同围压下不同砾石比例砂砾岩三轴压缩微裂缝数量及能量曲线
Figure 8. Number and energy curves of glutenite with different gravel ratios under different confining pressures in triaxial compression
-
[1] 赵永强, 宋振响, 王斌, 等. 准噶尔盆地油气资源潜力与中国石化常规-非常规油气一体化勘探策略[J]. 石油实验地质, 2023, 45(5): 872-881. doi: 10.11781/sysydz202305872ZHAO Yongqiang, SONG Zhenxiang, WANG Bin, et al. Resource potential in Junggar Basin and SINOPEC's integrated exploration strategy for conventional and unconventional petroleum[J]. Petro-leum Geology & Experiment, 2023, 45(5): 872-881. doi: 10.11781/sysydz202305872 [2] 邓继新, 柴康伟, 宋连腾, 等. 差异性成岩过程对百口泉组砂砾岩岩石物理特征的影响[J]. 地球物理学报, 2022, 65(11): 4448-4459. doi: 10.6038/cjg2022P0184DENG Jixin, CHAI Kangwei, SONG Lianteng, et al. The influence of diagenetic evolution on rock physical properties of sandy conglomerate of Baikouquan Formation[J]. Chinese Journal of Geophysics, 2022, 65(11): 4448-4459. doi: 10.6038/cjg2022P0184 [3] LIU Jiantong, GE Hongkui, ZHANG Zhenxin, et al. of mechanical contrast between the matrix and gravel on fracture propagation of glutenite[J]. Journal of Petroleum Science and Engineering, 2022, 208: 109639. doi: 10.1016/j.petrol.2021.109639 [4] AKRAM M S, SHARROCK G B, MITRA R. Investigating mechanics of conglomeratic rocks: of clast size distribution, scale and properties of clast and interparticle cement[J]. Bulletin of Engineering Geology and the Environment, 2019, 78(4): 2769-2788. doi: 10.1007/s10064-018-1274-x [5] 吴海光, 康逊, 秦明阳, 等. 准噶尔盆地玛湖凹陷百口泉组砂砾岩非均质储层孔隙结构特征与成因[J]. 中南大学学报(自然科学版), 2022, 53(9): 3337-3353. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD202209006.htmWU Haiguang, KANG Xun, QIN Mingyang, et al. Pore structure characteristics and genesis of heterogeneous conglomerate reservoir of Baikouquan Formation in Mahu Sag, Junggar Basin[J]. Journal of Central South University (Science and Technology), 2022, 53(9): 3337-3353. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD202209006.htm [6] 李永盛. 单轴压缩条件下四种岩石的蠕变和松弛试验研究[J]. 岩石力学与工程学报, 1995, 14(1): 39-47. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX501.005.htmLI Yongsheng. Creep and relaxation of 4 kinds of rock under uniaxial compression tests[J]. Chinese Journal of Rock Mechanics and Engineering, 1995, 14(1): 39-47. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX501.005.htm [7] 杨永杰, 王德超, 郭明福, 等. 基于三轴压缩声发射试验的岩石损伤特征研究[J]. 岩石力学与工程学报, 2014, 33(1): 98-104. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201401011.htmYANG Yongjie, WANG Dechao, GUO Mingfu, et al. Study of rock damage characteristics based on acoustic emission tests under triaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(1): 98-104. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201401011.htm [8] LIU Jiantong, WANG Jianbo, GE Hongkui, et al. Effect of gravel on rock failure in glutenite reservoirs under different confining pressures[J]. Petroleum Science, 2023, 20(5): 3022-3036. doi: 10.1016/j.petsci.2023.04.006 [9] 高阳, 郭鹏, 李晓, 等. 不同类型储层岩石三轴压缩变形破裂与声发射特征研究[J]. 工程地质学报, 2022, 30(4): 1169-1178. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ202204018.htmGAO Yang, GUO Peng, LI Xiao, et al. Investigation of triaxial compression failure and acoustic emission characteristics of different reservoir rocks[J]. Journal of Engineering Geology, 2022, 30(4): 1169-1178. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ202204018.htm [10] MENG Han, YANG Yuzhong, WU Liyun. Strength, deformation, and acoustic emission characteristics of raw coal and briquette coal samples under a triaxial compression experiment[J]. ACS Omega, 2021, 6(47): 31485-31498. doi: 10.1021/acsomega.1c03543 [11] MCBECK J, BEN-ZION Y, RENARD F. Fracture network localization preceding catastrophic failure in triaxial compression experiments on rocks[J]. Frontiers in Earth Science, 2021, 9: 778811. doi: 10.3389/feart.2021.778811 [12] LI Jiarun, DUAN Kang, MENG Han, et al. On the mechanical properties and failure mechanism of conglomerate specimens subjected to triaxial compression tests[J]. Rock Mechanics and Rock Engineering, 2023, 56(2): 973-995. doi: 10.1007/s00603-022-03110-4 [13] 孔晓璇, 刘重羊. 白砂岩力学参数尺寸效应实验研究[J]. 实验科学与技术, 2023, 21(5): 44-48. https://www.cnki.com.cn/Article/CJFDTOTAL-SYKS202305008.htmKONG Xiaoxuan, LIU Chongyang. Experimental study on size effect of white sandstone mechanical parameters[J]. Experiment Science and Technology, 2023, 21(5): 44-48. https://www.cnki.com.cn/Article/CJFDTOTAL-SYKS202305008.htm [14] 尤明庆, 华安增. 岩石试样破坏过程的能量分析[J]. 岩石力学与工程学报, 2002, 21(6): 778-781. doi: 10.3321/j.issn:1000-6915.2002.06.004YOU Mingqing, HUA Anzeng. Energy analysis on failure process of rock specimens[J]. Chinese Journal of Rock Mechanics and Engineering, 2002, 21(6): 778-781. doi: 10.3321/j.issn:1000-6915.2002.06.004 [15] 韩震宇, 李地元, 朱泉企, 等. 含端部裂隙大理岩单轴压缩破坏及能量耗散特性[J]. 工程科学学报, 2020, 42(12): 1588-1596. https://www.cnki.com.cn/Article/CJFDTOTAL-BJKD202012005.htmHAN Zhenyu, LI Diyuan, ZHU Quanqi, et al. Uniaxial compression failure and energy dissipation of marble specimens with flaws at the end surface[J]. Chinese Journal of Engineering, 2020, 42(12): 1588-1596. https://www.cnki.com.cn/Article/CJFDTOTAL-BJKD202012005.htm [16] YAN Yuelong, XU Tao, ZHANG Yunjie, et al. Numerical simulation of the effect of joint orientation on the failure strength of rock[J]. Applied Mechanics and Materials, 2013, 477-478: 577-581. doi: 10.4028/www.scientific.net/AMM.477-478.577 [17] 李兆霖, 周伟, 王连国, 等. 含随机裂隙岩石真三轴破裂演化数值模拟[J]. 中国矿业大学学报, 2023, 52(1): 43-51. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD202301005.htmLI Zhaolin, ZHOU Wei, WANG Lianguo, et al. Numerical simulation of true triaxial fracture evolution of rocks with random fracture[J]. Journal of China University of Mining & Technology, 2023, 52(1): 43-51. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD202301005.htm [18] XIA Ming, ZHOU Keping. Particle simulation of the failure process of brittle rock under triaxial compression[J]. International Journal of Minerals, Metallurgy, and Materials, 2010, 17(5): 507-513. doi: 10.1007/s12613-010-0350-4 [19] ZHANG Yulong, SHAO Jianfu, DE SAXCÉ G, et al. Study of deformation and failure in an anisotropic rock with a three-dimensional discrete element model[J]. International Journal of Rock Mechanics and Mining Sciences, 2019, 120: 17-28. doi: 10.1016/j.ijrmms.2019.05.007 [20] 刘京铄, 范金星, 李娟, 等. 单轴压缩下横观各向同性岩石破裂过程声发射特性的离散元模拟[J]. 湖南工业大学学报, 2016, 30(4): 5-9. doi: 10.3969/j.issn.1673-9833.2016.04.002LIU Jingshuo, FANG Jinxing, LI Juan, et al. DEM simulation of acoustic emission characteristics in the failure process of transversely isotropic rocks under uniaxial compression[J]. Journal of Hunan University of Technology, 2016, 30(4): 5-9. doi: 10.3969/j.issn.1673-9833.2016.04.002 [21] ZHAO Yu, ZHOU Zhiqiang, BI Jing, et al. Numerical simulation the fracture of rock in the framework of plastic-bond-based SPH and its applications[J]. Computers and Geotechnics, 2023, 157: 105359. doi: 10.1016/j.compgeo.2023.105359 [22] 袁康, 蒋宇静, 李亿民, 等. 基于颗粒离散元法岩石压缩过程破裂机制宏细观研究[J]. 中南大学学报(自然科学版), 2016, 47(3): 913-922. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201603026.htmYUAN Kang, JIANG Yujing, LI Yimin, et al. Macro-micro mechanical research on failure mechanism of rock subjected to compression loading based on DEM[J]. Journal of Central South University (Science and Technology), 2016, 47(3): 913-922. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201603026.htm [23] CAO Minghui, YANG Shengqi, TIAN Wenling, et al. Three-dimensional discrete element simulation of the triaxial cyclic loading of sandstone based on a nonlinear parallel-bonded stress corrosion model[J]. Computers and Geotechnics, 2024, 168: 106167. doi: 10.1016/j.compgeo.2024.106167 [24] CHO N, MARTIN C D, SEGO D C. Development of a shear zone in brittle rock subjected to direct shear[J]. International Journal of Rock Mechanics and Mining Sciences, 2008, 45(8): 1335-1346. doi: 10.1016/j.ijrmms.2008.01.019 [25] CHONG Zhaohui, LI Xuehua, HOU Peng, et al. Numerical investigation of bedding plane parameters of transversely isotropic shale[J]. Rock Mechanics and Rock Engineering, 2017, 50(5): 1183-1204. doi: 10.1007/s00603-016-1159-x -
下载:
图(9)
计量
- 文章访问数: 121
- HTML全文浏览量: 47
- PDF下载量: 17
- 被引次数: 0
苏公网安备32021102000780号