岩性油气藏 ›› 2026, Vol. 38 ›› Issue (5): 170–178.doi: 10.12108/yxyqc.20260516

• 石油工程与油气田开发 • 上一篇    下一篇

基于CT扫描三维重构的煤岩可压裂性实验

曾凡辉1(), 杨维鑫1,2, 郭建春1, 张宇1, 张然3   

  1. 1 西南石油大学·油气藏地质及开发工程全国重点实验室， 成都 610500
    2 中国石化勘探分公司， 成都 610051
    3 西华大学 机械工程学院， 成都 611743
  • 收稿日期:2025-09-17 修回日期:2025-11-15 出版日期:2026-09-01 发布日期:2026-09-04
  • 第一作者:曾凡辉（1980—），男，博士，教授，主要从事储集层增产改造理论与技术方面的科研与教学工作。地址：（610500）四川省成都市新都区新都大道8号。Email:zengfanhui023024@126.com。
  • 基金资助:
    国家自然科学基金面上项目“基于知识数据融合的深层页岩压裂参数自适应调控研究”(52574047);“大数据驱动的深层页岩压裂参数协同优化与实时调控研究”(52374045);四川省科技教育联合基金重点项目“深层页岩水平井压裂参数智能优化与在线调控研究”(2025NSFSC2008)

Experiment on the fracability of coal rocks based on CT scanning and 3D reconstruction

ZENG Fanhui1(), YANG Weixin1,2, GUO Jianchun1, ZHANG Yu1, ZHANG Ran3   

  1. 1 State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation·Southwest Petroleum University, Chengdu 610500， China
    2 Sinopec Exploration Company, Chengdu 610500， China
    3 School of Mechanical Engineering, Xihua University, Chengdu 611743， China
  • Received:2025-09-17 Revised:2025-11-15 Online:2026-09-01 Published:2026-09-04

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摘要：

针对煤层气藏传统可压裂性评价方法难以兼顾裂缝形态与流动连通性的问题，利用真三轴水力压裂设备，以4组200 mm×200 mm×200 mm的原煤立方体样品开展不同压裂介质、不同地应力差、不同泵注速率条件下的压裂对比实验；结合高分辨率CT扫描与三维重构技术，定量获取裂缝表面积并计算三维分形维数，将可压裂性定义为单位改造体积内的裂缝总表面积，对不同应力条件与压裂流体类型对裂缝发育特征的影响进行了系统分析。研究结果表明：①液态CO2黏度低、扩散能力强，能够有效提高孔隙压力并降低破裂压力，显著增强裂缝复杂性；与清水相比，液态CO2作为压裂介质的起裂压力降低了13.8%，裂缝表面积增加了50.1%。②裂缝复杂度与三维分形维数呈高度正相关，三维分形维数可作为反映储层可压裂性的有效量化指标。③相同实验条件下，水平主应力差由5.00 MPa降至3.00 MPa时，储层可压裂性提高了14.7%；当泵注速率由30 mL/min提高至60 mL/min时，储层可压裂性提高了11.3%；相较于清水压裂，液态CO2压裂可使储层的可压裂性提高50.7%。

关键词: 煤岩, 真三轴压裂实验, CO2压裂, 裂缝扩展, 三维重构, 分形维数, 裂缝面积

Abstract:

In response to the problem that conventional fracability evaluation methods for coalbed methane reservoirs are difficult to balance fracture morphology and flow connectivity, fracturing comparison experiments were conducted using a true triaxial hydraulic fracturing system on four groups of raw coal cubic specimens with dimensions of 200 mm×200 mm×200 mm under varying conditions of fracturing fluid, in-situ stress difference, and pumping rate. Combined with high-resolution CT scanning and 3D reconstruction technology, the fracture surface area was quantitatively obtained and the 3D fractal dimension was calculated. Fracability was defined as the total fracture surface area per unit modified reservoir volume, and effects of in-situ stress conditions and fracturing fluid type on fracture development characteristics were systematically analyzed. Research results show that: （1） With low viscosity and strong diffusivity, liquid CO2 can effectively increase pore pressure and reduce breakdown pressure, thus significantly improve the fracture complexity. Compared with clear water, liquid CO2 as a fracturing fluid reduces the initiation pressure by 13.8% and increases the fracture surface area by 50.1%. （2） Fracture complexity is highly positively correlated with the 3D fractal dimension, which can be used as an effective quantitative index to characterize reservoir fracability. （3） Under the same experimental conditions, when the horizontal principal stress difference decreases from 5.00 MPa to 3.00 MPa, reservoir fracability increases by 14.7%.When the pumping rate increases from 30 mL/min to 60 mL/min, reservoir fracability increases by 11.3%. Compared with water fracturing, liquid CO2 fracturing improves reservoir fracability by 50.7%.

Key words: coal rock, true triaxial fracturing experiment, CO2 fracturing, fracture propagation, 3D reconstruction, fractal dimension, fracture surface area

中图分类号: 

  • TE371

图1

山西晋城大同煤矿TS-X井下二叠统山西组3号煤层深度600 m处煤岩天然裂缝发育情况"

图2

山西晋城大同煤矿下二叠统山西组煤层真三轴压裂实验岩样"

表1

山西晋城大同煤矿下二叠统山西组煤岩天然裂缝密度及力学参数测试结果"

煤样 天然裂缝密度/（条·m-2） 杨氏模量/MPa 泊松比
1# 45 5 563.58 0.29
2# 47 4 570.56 0.31
3# 42 4 860.51 0.34
4# 56 2 920.32 0.41

图3

山西晋城大同煤矿下二叠统山西组煤岩钻孔模拟井筒（a）及封胶（b）"

图4

真三轴压裂模拟实验设备"

表2

山西晋城大同煤矿下二叠统山西组煤岩真三轴压裂模拟实验参数设定"

煤样 压裂
介质		 最小水平
主应力/MPa		 最大水平
主应力/MPa		 垂向
应力/MPa		 泵注速率/(mL·min-1)
1# 液态CO2 7.00 12.00 9.00 30
2# 液态CO2 7.00 10.00 9.00 60
3# 液态CO2 7.00 10.00 9.00 30
4# 清水 7.00 10.00 9.00 60

图5

山西晋城大同煤矿下二叠统山西组煤样真三轴压裂模拟实验压裂时泵注曲线"

图6

山西晋城大同煤矿下二叠统山西组煤样真三轴压裂模拟实验压裂后裂缝二维平面特征 注：σh、σH、σv分别为最小水平主应力、最大水平主应力及垂向应力，MPa；Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ分别指示不同的裂缝形态类型，Ⅰ. 对称双翼主裂缝；Ⅱ. 天然裂缝或层理；Ⅲ. 放射性次生裂缝网络；Ⅳ. 主裂缝垂向穿层扩展，形成近井筒高密度三维辐射结构；Ⅴ. 天然裂缝发生剪切滑移并错位，裂缝界面模糊且宽度变化不一（a）—（b） 分别为1#煤样压裂前不同水平应力方向剖面图；（c）—（d） 分别为1#煤样在泵注速率为30 mL/min、水平应力差为5.00 MPa条件下进行液态CO2压裂后不同应力方向剖面图；（e）—（f） 分别为2#煤样压裂前不同水平主应力方向剖面图；（g）—（h） 分别为2#煤样在泵注速率为60 mL/min、水平应力差为3.00 MPa条件下进行液态CO2压裂后剖面图；（i）—（j） 分别为3#煤样压裂前不同应力方向剖面图；（k）—（l） 分别为3#煤样在泵注速率为30 mL/min、水平应力差为3.00 MPa条件下进行液态CO2压裂后剖面图；（m）—（n） 分别为4#煤样压裂前不同水平应力方向剖面图；（o）—（p） 分别为4#煤样在泵注速率为60 mL/min、水平应力差为3.00 MPa条件下进行清水压裂后不同水平应力方向剖面图。"

图7

山西晋城大同煤矿下二叠统山西组煤样真三轴压裂模拟实验压裂前后裂缝三维CT图"

图8

山西晋城大同煤矿下二叠统山西组煤样真三轴压裂模拟实验压裂后的三维裂缝模型"

表3

山西晋城大同煤矿下二叠统山西组煤样真三轴压裂模拟实验压裂后单位改造体积裂缝面积及分形维数"

煤样 压裂
介质		 压裂前裂缝
面积/104 mm2		 压裂后裂缝
面积/104 mm2		 裂缝面积增量/104 mm2 单位改造体积内裂缝的
总表面积/（10-2 mm2·mm-3）		 裂缝二维
分形维数		 裂缝三维
分形维数
1# 液态CO2 0.007 2 13.58 13.57 1.70 1.091 2.087
2# 液态CO2 1.450 0 17.32 15.87 2.17 1.127 2.212
3# 液态CO2 0.007 6 15.64 15.63 1.95 1.152 2.163
4# 清水 2.080 0 11.54 9.46 1.44 1.052 2.058

图9

三维盒计数法流程示意图（据文献[22]修改） 注：图中的r1、r2、r3均为盒子边长，m。"

图10

山西晋城大同煤矿下二叠统山西组煤样真三轴压裂模拟实验压裂后三维重构裂缝盒计数法示意图"

图11

山西晋城大同煤矿下二叠统山西组煤样真三轴压裂模拟实验压裂后裂缝三维分形维数 注：r为盒子边长，m；N(r)为覆盖图像的盒子数，个；D为盒维数法得到的分形维数。"

图12

山西晋城大同煤矿下二叠统山西组煤样模拟实验压裂后裂缝分形维数与单位改造体积内裂缝总表面积的拟合关系"

[1] 邹才能, 杨智, 黄士鹏, 等. 煤系天然气的资源类型,形成分布与发展前景[J]. 石油勘探与开发, 2019, 46(3):433-442.
ZOU Caineng, YANG Zhi, HUANG Shipeng, et al. Resource types,formation,distribution and prospects of coal-measure gas[J]. Petroleum Exploration and Development, 2019, 46(3):433-442.
[2] 王青, 田冲, 罗超, 等. 四川盆地遂宁—合江地区二叠系龙潭组煤岩气储层特征及勘探前景[J]. 岩性油气藏, 2025, 37(4):26-37.
WANG Qing, TIAN Chong, LUO Chao, et al. Characteristics and exploration prospects of coal-rock gas reservoirs in Per-mian Longtan Formation in Suining-Hejiang area,Sichuan Basin[J]. Lithologic Reservoirs, 2025, 37(4):26-37.
[3] ZENG Fanhui, PENG Fan, GUO Jianchun, et al. Gas transport study in the confined microfractures of coal reservoirs[J]. Journal of Natural Gas Science and Engineering, 2019, 68:102920.
[4] 卞晓冰, 侯磊, 蒋廷学, 等. 深层页岩裂缝形态影响因素[J]. 岩性油气藏, 2019, 31(6):161-168.
BIAN Xiaobing, HOU Lei, JIANG Tingxue, et al. Influencing factors of fracture geometry in deep shale gas wells[J]. Lithologic Reservoirs, 2019, 31(6):161-168.
[5] ZENG Fanhui, GONG Gaobin, ZHANG Yu, et al. Fracability evaluation of shale reservoirs considering rock brittleness,fracture toughness,and hydraulic fracturing-induced effects[J]. Geoenergy Science and Engineering, 2023, 229:1-14.
[6] CHONG K K, GRIESER W V, PASSMAN A, et al. A completions guide book to shale-play development:A review of successful approaches towards shale-play stimulation in the last two decades[R]. Calgary, Society of Petroleum Engineers Canadian Unconventional Resources and International Petroleum Conference, 2010.
[7] LI Jianhua, XIE Heping, LU Jun, et al. New permeability model of deep coal rock considering the structure and 3D stress compression-induced anisotropy[J]. Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 2022, 8(6):204.
[8] 彭文春, 米洪刚, 徐立富, 等. 神府区块深部煤储层可压性评价方法及应用[J]. 煤炭科学技术, 2025, 53(3):238-247.
PENG Wenchun, MI Honggang, XU Lifu, et al. Fracability evaluation and classification of deep coal reservoirs in the Shenfu block[J]. Coal Science and Technology, 2025, 53(3):238-247.
[9] 李倩, 李童, 蔡益栋, 等. 煤层气储层水力裂缝扩展特征与控因研究进展[J]. 煤炭学报, 2023, 48(12):4443-4460.
LI Qian, LI Tong, CAI Yidong, et al. Research progress on hydraulic fracture characteristics and controlling factors of coalbed methane reservoirs[J]. Journal of China Coal Society, 2023, 48(12):4443-4460.
[10] CHEN Lipeng, WANG Lei, LIU Huaiqian, et al. Study on the micro-fracture-structure and permeability behavior of coal under the action of CO2 based on micro-CT[J]. Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 2025, 11(1):25.
[11] 孟召平, 刘翠丽, 纪懿明. 煤层气/页岩气开发地质条件及其对比分析[J]. 煤炭学报, 2013, 38(5):728-736.
MENG Zhaoping, LIU Cuili, JI Yiming. Geological conditions of coalbed methane and shale gas exploitation and their comparison analysis[J]. Journal of China Coal Society, 2013, 38(5):728-736.
[12] 翟文宝, 李军, 周英操, 等. 基于测井资料的页岩储层可压裂性评价新方法[J]. 岩性油气藏, 2018, 30(3):112-123.
ZHAI Wenbao, LI Jun, ZHOU Yingcao, et al. New evaluation method of shale reservoir fracability based on logging data[J]. Lithologic Reservoirs, 2018, 30(3):112-123.
[13] YUAN Junliang, ZHOU Jianliang, LIU Shujie, et al. An improved fracability-evaluation method for shale reservoirs based on new fracture toughness-prediction models[J]. SPE Journal, 2017, 22(5):1704-1713.
[14] JIN Xiaochun, SHAH S N, ROEGIERS J C, et al. An integrated petrophysics and geomechanics approach for fracability evaluation in shale reservoirs[J]. SPE Journal, 2015, 20(3):518-526.
[15] 艾林, 周明顺, 张杰, 等. 基于煤岩脆性指数的煤体结构测井定量判识[J]. 岩性油气藏, 2017, 29(2):139-144.
AI Lin, ZHOU Mingshun, ZHANG Jie, et al. Quantitative identification of coal structure based on coal rock brittleness index by logging data[J]. Lithologic Reservoirs, 2017, 29(2):139-144.
[16] LI Yuwei, LONG Min, ZUO Lihua, et al. Brittleness evaluation of coal based on statistical damage and energy evolution theory[J]. Journal of Petroleum Science and Engineering, 2019, 172:753-763.
[17] JARVIE D M, HILL R J, RUBLE T E, et al. Unconventional shale-gas systems:The Mississippian Barnett Shale of north-central Texas as one model for thermogenic shale-gas assessment[J]. AAPG Bulletin, 2007, 91(4):475-499.
[18] 袁俊亮, 邓金根, 张定宇, 等. 页岩气储层可压裂性评价技术[J]. 石油学报, 2013, 34(3):523-527.
YUAN Junliang, DENG Jingen, ZHANG Dingyu, et al. Fracability evaluation of shale-gas reservoirs[J]. Acta Petrolei Sinica, 2013, 34(3):523-527.
[19] 王登科, 曾凡超, 王建国, 等. 显微工业CT的受载煤样裂隙动态演化特征与分形规律研究[J]. 岩石力学与工程学报, 2020, 39(6):1165-1174.
WANG Dengke, ZENG Fanchao, WANG Jianguo, et al. Dynamic evolution characteristics and fractal law of loaded coal fractures by micro industrial CT[J]. Chinese Journal of Rock Mechanics and Engineering, 2020, 39(6):1165-1174.
[20] SUI Lili, JU Yang, YANG Yongming, et al. A quantification method for shale fracability based on analytic hierarchy process[J]. Energy, 2016, 115:637-645.
[21] SUI Lili, YU Jian, CANG Dingbang, et al. The fractal description model of rock fracture networks characterization[J]. Chaos,Solitons & Fractals, 2019, 129:71-76.
[22] WANG Fei, WU Xiang, DUAN Chaowei, et al. Quantitative characterization and fracturability evaluation of shale fractures based on 3D CT reconstruction[J]. Progress in Geophysics, 2023, 38(5):2147-2159.
[23] 蒋长宝, 付银兰, 王光淇. 水力压裂煤裂隙网络表征与造缝性能评估试验研究[J]. 煤炭科学技术, 2023, 51(6):62-71.
JIANG Changbao, FU Yinlan, WANG Guangqi. Experimental study on characterization hydraulic fracturing coal fracture network and evolution of fracture forming performance[J]. Coal Science and Technology, 2023, 51(6):62-71.
[24] CIPOLLA C L, WARPINSKI N R, MAYERHOFER M J, et al. The relationship between fracture complexity,reservoir properties,and fracture-treatment design[J]. SPE Production & Operations, 2010, 25(4):438-452.
[25] 侯冰, 陈勉, 李志猛, 等. 页岩储集层水力裂缝网络扩展规模评价方法[J]. 石油勘探与开发, 2014, 41(6):763-768.
HOU Bing, CHEN Mian, LI Zhimeng, et al. Propagation area evaluation of hydraulic fracture networks in shale gas reservoirs[J]. Petroleum Exploration and Development, 2014, 41(6):763-768.
[26] 刘向君, 王小军, 赵保伟, 等. 砂砾岩储集层水力压裂裂缝扩展规律与可压性评价[J]. 新疆石油地质, 2023, 44(2):169-177.
LIU Xiangjun, WANG Xiaojun, ZHAO Baowei, et al. Propagation of hydraulic fractures and fracability evaluation of sandy conglomerate reservoirs[J]. Xinjiang Petroleum geology, 2023, 44(2):169-177.
[27] 丁勇, 马新星, 叶亮, 等. CO2破岩机理及压裂工艺技术研究[J]. 岩性油气藏, 2018, 30(6):151-159.
DING Yong, MA Xinxing, YE Liang, et al. Rock breaking mechanism of CO2 and fracturing technology[J]. Lithologic Reservoirs, 2018, 30(6):151-159.
[28] 寇淑清, 杨宏宇, 高岩, 等. 裂解连杆断裂结合面缺损面积定量描述与分析[J]. 吉林大学学报(工学版), 2013, 43(6):1541-1545.
KOU Shuqing, YANG Hongyu, GAO Yan, et al. Quantitative description and analysis of defect area of fracture surface of splitting connecting rod[J]. Journal of Jilin University (Engineering and Technology Edition), 2013, 43(6):1541-1545.
[29] 徐祖新. 基于CT扫描图像的页岩储层非均质性研究[J]. 岩性油气藏, 2014, 26(6):46-49.
XU Zuxin. Heterogeneity of shale reservoirs based on CT images[J]. Lithologic Reservoirs, 2014, 26(6):46-49
[30] WU Mingyang, WANG Wensong, SHI Di, et al. Improved box-counting methods to directly estimate the fractal dimension of a rough surface[J]. Measurement, 2021, 177:109303.
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