煤系页岩储层多气共采水力裂缝扩展规律试验研究

王士国; 金衍; 谭鹏; 夏阳

doi:10.11779/CJGE202212016

煤系页岩储层多气共采水力裂缝扩展规律试验研究 English Version

王士国^{1, 2,},
金衍^{1, 2, ,},
谭鹏³,
夏阳^{1, 2}

1.
中国石油大学（北京）油气资源与探测国家重点实验室，北京 102249
2.
中国石油大学（北京）石油工程学院，北京 102249
3.
中国石油集团工程技术研究院有限公司，北京 102206

基金项目:

国家自然科学基金面上项目 51874321

国家自然科学基金青年科学基金项目 51904318

中国石油大学(北京)科研启动基金项目—青年拔尖人才 2462018YJRC014

详细信息

作者简介:
王士国(1996—)，男，博士研究生，主要从事石油工程岩石力学、水力压裂等方面研究工作。E-mail: wangshiguo1996@163.com

通讯作者:
金衍, E-mail: jinyancup@163.com

中图分类号: TU45
计量
- 文章访问数: 195
- HTML全文浏览量: 36
- PDF下载量: 29
出版历程
- 收稿日期: 2021-10-17
- 网络出版日期: 2022-12-13
- 刊出日期: 2022-11-30

Experimental investigation on hydraulic fracture propagation of coal shale reservoirs under multi-gas co-production

WANG Shi-guo^{1, 2,},
JIN Yan^{1, 2, ,},
TAN Peng³,
XIA Yang^{1, 2}

1.
State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, China
2.
College of Petroleum Engineering, China University of Petroleum-Beijing, Beijing 102249, China
3.
China National Petroleum Corporation Engineering Technology R & D Company Limited, Beijing 102206, China

摘要

摘要: 多岩性组合煤系页岩储层在纵向上交替发育页岩、煤岩及灰岩等多类含气层，压裂后储层间的连通程度与裂缝复杂程度是决定多气共采成败的关键。通过制作模拟煤系页岩储层的多岩性组合层状岩石试样，开展真三轴压裂物理模拟试验，分析了水力裂缝纵向扩展形态及多因素影响规律。试验结果表明：岩性界面、页岩层理及煤岩割理等非连续结构面对水力裂缝垂向扩展具有显著抑制作用，水力裂缝缝高扩展往往呈非对称扩展模式；值为0.1的低垂向应力差系数更易被弱结构面捕获，高垂向应力差系数、高压裂液注入速率有利于裂缝垂向穿层扩展，水力裂缝穿透至煤岩中可激活割理系统形成复杂裂缝网络。试验结果证实了多岩性煤系页岩储层多气共采的可行性，研究结果亦可为认识煤系地层水力裂缝形态及指导现场压裂施工提供参考。
- 煤系页岩储层 /
- 多气共采 /
- 水力压裂 /
- 裂缝穿层 /
- 缝高扩展 /
- 岩性界面 /
- 层理面
Abstract: The gas-bearing formations, including shale, coal and limestone rock, are alternately and vertically developed in coal shale reservoirs. Multiple unconventional natural gases can be exploited together through the hydraulic fracture longitudinally connecting different production layers. Therefore, the degrees of formation connection and fracture complexity are the two key factors to determine the results of gas co-production. The true tri-axial hydraulic tests are carried out on the samples of artificial coal shale strata, which are comprised of different lithological combinations of layered rock. The vertical propagation geometries of hydraulic fractures are analyzed and the effects of different factors on the fracture patterns are summarized. The results show that the weak planes, such as lithological interfaces, bedding planes and coal cleats, have obviously inhibitive effects on the fracture-height growth, and the fracture height propagation always exhibits asymmetric characteristics. The trajectory of hydraulic fracture is easier to be arrested by the weak planes for the case of low vertical stress difference coefficient, as when the value is equal to 0.1. The high vertical stress difference coefficient and high fluid injection rate are beneficial for the hydraulic fracture to cross the interface vertically. In addition, as the hydraulic fracture penetrates the lithological interfaces, the cleat system can be activated, which improves complexity degree of hydraulic fractures. The results are expected to provide a guideline for understanding the hydraulic fracture morphology of coal strata and designing the field fracturing operation.
- coal shale reservoir /
- multiple gas co-production /
- hydraulic fracture /
- layer penetration /
- fracture height propagation /
- lithological interface /
- bedding plane

HTML全文

图 1 试样制备流程图

Figure 1. Process of preparing samples

下载: 全尺寸图片幻灯片

图 2 水平井地应力加载示意图

Figure 2. Schematic diagram of horizontal well in-situ stress loading on samples

下载: 全尺寸图片幻灯片

图 3 试件压裂后水力裂缝形态

Figure 3. Fracture geometry of sample after fracturing

下载: 全尺寸图片幻灯片

图 4 ^#2，^#4试样裂缝扩展形态对比

Figure 4. Schematic comparison of fracture penetration of samples ^#2 and ^#4

下载: 全尺寸图片幻灯片

图 5 ^#4试样煤岩中椭圆形渗透区局部图和不同注入速率下裂缝路径复杂程度^[20]

Figure 5. Partial view of elliptical permeability zone of coal in sample ^#4 and complexities of hydraulic fracture path under different flow rates

下载: 全尺寸图片幻灯片

图 6 压裂后裂缝垂向扩展形态

Figure 6. Schematic diagram of vertical propagation geometry of hydraulic fractures after fracturing

下载: 全尺寸图片幻灯片

图 7 压裂过程中泵压曲线

Figure 7. Pump pressure curves during hydraulic fracturing

下载: 全尺寸图片幻灯片

表 1 不同岩性人工试样岩石力学参数

Table 1 Summary of mechanical parameters of rock

岩性	质量比 (石英砂︰水泥︰煤粉︰水)	弹性模量 /GPa	泊松比	抗张强度 /MPa	抗压强度 /MPa
煤岩	5︰0.92︰1︰1	5.23	0.34	0.60	11
页岩	5︰1.03︰0︰1	11.45	0.23	1.87	18
灰岩	5︰1.52︰0︰1	21.79	0.17	5.96	36

下载: 导出CSV

表 2 试验参数设计表

Table 2 Summary of test parameters

试样编号	组合类型	垂向应力差系数	三向有效地应力/MPa			注入速率/ ( ${{\text{mL}}} \cdot {{\text{mi}}}{{{\text{n}}}^{ - {{\text{1}}}}}$ )	黏度/ ( ${{\text{mPa}}} \cdot {{\text{s}}}$ )
试样编号	组合类型	垂向应力差系数	${\sigma _{{\text{v}}}}$	${\sigma _{{\text{H}}}}$	${\sigma _{{\text{h}}}}$		黏度/ ( ${{\text{mPa}}} \cdot {{\text{s}}}$ )
^#1	煤岩-页岩-煤岩	0.10	22	21	20	20	3
^#2	煤岩-页岩-灰岩	0.10	22	21	20	20	3
^#3	煤岩-页岩-煤岩	0.47	22	21	15	10	3
^#4	煤岩-页岩-灰岩	0.47	22	21	15	20	3

下载: 导出CSV

参考文献(21)

[1]	石林, 史璨, 田中兰, 等. 中石油页岩气开发中的几个岩石力学问题[J]. 石油科学通报, 2019, 4(3): 223–232. https://www.cnki.com.cn/Article/CJFDTOTAL-SYKE201903001.htm SHI Lin, SHI Can, TIAN Zhong-lan, et al. Several rock mechanics problems in the development of shale gas in Petro China[J]. Petroleum Science Bulletin, 2019, 4(3): 223–232. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-SYKE201903001.htm
[2]	孟尚志, 侯冰, 张健, 等. 煤系"三气"共采产层组压裂裂缝扩展物模试验研究[J]. 煤炭学报, 2016, 41(1): 221–227. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201601030.htm MENG Shang-zhi, HOU Bing, ZHANG Jian, et al. Experimental research on hydraulic fracture propagation through mixed layers of shale, tight sand and coal seam[J]. Journal of China Coal Society, 2016, 41(1): 221–227. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201601030.htm
[3]	刘合, 王素玲, 姜民政, 等. 基于数字散斑技术的垂直裂缝扩展实验[J]. 石油勘探与开发, 2013, 40(4): 486–491. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201304014.htm LIU He, WANG Su-ling, JIANG Min-zheng, et al. Experiments of vertical fracture propagation based on the digital speckle technology[J]. Petroleum Exploration and Development, 2013, 40(4): 486–491. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201304014.htm
[4]	侯冰, 武安安, 常智, 等. 页岩油储层多甜点压裂裂缝垂向扩展试验研究[J]. 岩土工程学报, 2021, 43(7): 1322–1330. doi: 10.11779/CJGE202107018 HOU Bing, WU An-an, CHANG Zhi, et al. Experimental study on vertical propagation of fractures of multi-sweet of spots shale oil reservoir[J]. Chinese Journal of Geotechnical Engineering, 2021, 43(7): 1322–1330. (in Chinese) doi: 10.11779/CJGE202107018
[5]	衡帅, 杨春和, 曾义金, 等. 页岩水力压裂裂缝形态的试验研究[J]. 岩土工程学报, 2014, 36(7): 1243–1251. doi: 10.11779/CJGE201407008 HENG Shuai, YANG Chun-he, ZENG Yi-jin, et al. Experimental study on hydraulic fracture geometry of shale[J]. Chinese Journal of Geotechnical Engineering, 2014, 36(7): 1243–1251. (in Chinese) doi: 10.11779/CJGE201407008
[6]	BUNGER A P, ZHANG X, JEFFREY R G. Parameters affecting the interaction among closely spaced hydraulic fractures[J]. SPE Journal, 2012, 17(1): 292–306. doi: 10.2118/140426-PA
[7]	夏彬伟, 刘浪, 彭子烨, 等. 致密砂岩水平井多裂缝扩展及转向规律研究[J]. 岩土工程学报, 2020, 42(8): 1549–1555. doi: 10.11779/CJGE202008021 XIA Bin-wei, LIU Lang, PENG Zi-ye, et al. Multi-fracture propagation and deflection laws of horizontal wells in tight sandstone[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(8): 1549–1555. (in Chinese) doi: 10.11779/CJGE202008021
[8]	谭鹏, 金衍, 陈刚. 四川盆地不同埋深龙马溪页岩水力裂缝缝高延伸形态及差异分析[J]. 石油科学通报, 2022, 7(1): 61-70. https://www.cnki.com.cn/Article/CJFDTOTAL-SYKE202201006.htm TAN Peng, JIN Yan, CHEN Gang. Differences and causes of fracture height geometry for Longmaxi shale with different burial depths in the Sichuan Basin[J]. Petroleum Science Bulletin, 2022, 7(1): 61–70. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-SYKE202201006.htm
[9]	ZHANG X, WU B S, JEFFREY R G, et al. A pseudo-3D model for hydraulic fracture growth in a layered rock[J]. International Journal of Solids and Structures, 2017, 115/116: 208–223.
[10]	TANG J Z, WU K. A 3-D model for simulation of weak interface slippage for fracture height containment in shale reservoirs[J]. International Journal of Solids and Structures, 2018, 144/145: 248–264.
[11]	TANG J Z, WU K, ZUO L H, et al. Investigation of rupture and slip mechanisms of hydraulic fractures in multiple-layered formations[J]. SPE Journal, 2019, 24(5): 2292–2307.
[12]	XIE J, TANG J Z, YONG R, et al. A 3-D hydraulic fracture propagation model applied for shale gas reservoirs with multiple bedding planes[J]. Engineering Fracture Mechanics, 2020, 228: 106872.
[13]	WAN L M, HOU B, MENG H, et al. Experimental investigation of fracture initiation position and fluid viscosity effect in multi-layered coal strata[J]. Journal of Petroleum Science and Engineering, 2019, 182: 106310.
[14]	FU S H, HOU B, XIA Y, et al. The study of hydraulic fracture height growth in coal measure shale strata with complex geologic characteristics[J]. Journal of Petroleum Science and Engineering, 2022, 211: 110164.
[15]	唐鹏飞. 致密油水平井裂缝穿层及延伸规律[J]. 大庆石油地质与开发, 2019, 38(6): 169–174. https://www.cnki.com.cn/Article/CJFDTOTAL-DQSK201906024.htm TANG Peng-fei. Fracture penetration and propagation laws in tight-oil horizontal wells[J]. Petroleum Geology & Oilfield Development in Daqing, 2019, 38(6): 169–174. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-DQSK201906024.htm
[16]	柳贡慧, 庞飞, 陈治喜. 水力压裂模拟实验中的相似准则[J]. 石油大学学报(自然科学版), 2000, 24(5): 45–48, 6. https://www.cnki.com.cn/Article/CJFDTOTAL-SYDX200005013.htm LIU Gong-hui, PANG Fei, CHEN Zhi-xi. Development of scaling laws for hydraulic fracture simulation tests[J]. Journal of the University of Petroleum, China, 2000, 24(5): 45–48, 6. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-SYDX200005013.htm
[17]	侯冰, 程万, 陈勉, 等. 裂缝性页岩储层水力裂缝非平面扩展实验[J]. 天然气工业, 2014, 34(12): 81–86. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201412016.htm HOU Bing, CHENG Wan, CHEN Mian, et al. Experiments on the non-planar extension of hydraulic fractures in fractured shale gas reservoirs[J]. Natural Gas Industry, 2014, 34(12): 81–86. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201412016.htm
[18]	周健, 陈勉, 金衍, 等. 裂缝性储层水力裂缝扩展机理试验研究[J]. 石油学报, 2007, 28(5): 109–113. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB200705021.htm ZHOU Jian, CHEN Mian, JIN Yan, et al. Experimental study on propagation mechanism of hydraulic fracture in naturally fractured reservoir[J]. Acta Petrolei Sinica, 2007, 28(5): 109–113. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB200705021.htm
[19]	TAN P, JIN Y, HAN K, et al. Analysis of hydraulic fracture initiation and vertical propagation behavior in laminated shale formation[J]. Fuel, 2017, 206: 482–493.
[20]	YU H, DAHI TALEGHANI A, LIAN Z H. On how pumping hesitations may improve complexity of hydraulic fractures, a simulation study[J]. Fuel, 2019, 249: 294–308.
[21]	LIU C, ZHANG J N, YU H, et al. New insights of natural fractures growth and stimulation optimization based on a three-dimensional cohesive zone model[J]. Journal of Natural Gas Science and Engineering, 2020, 76: 103165.