结合大尺寸真三轴水平井水力压裂物理模拟试验,对龙马溪组页岩的起裂、扩展以及扩展过程中水力裂缝与天然裂缝的相互作用进行了详细的力学分析,并基于断裂力学和流体力学理论知识,建立了水力裂缝起裂和扩展力学模型,推导了相应的断裂力学判据。结果表明:①起裂方式可以分为3类,即页岩本体张性起裂、沿天然裂缝(层理面)的剪切起裂、沿天然裂缝(层理面)的张拉起裂;②水力裂缝扩展过程中,随着裂缝长度的增加,泵压逐渐减小,最终趋于一个略大于最小水平主应力的稳定值;③水力裂缝与天然裂缝的相互作用类型可根据天然裂缝是否开启分为以下5类,即剪切天然裂缝后穿过、直接穿过天然裂缝、从天然裂缝一端穿过、同时从天然裂缝两端穿过、从某一弱面穿过。研究结果可为页岩气藏水平井压裂开采提供有力技术支持。
Abstract
Physical modelling of large-scale true triaxial test on hydraulic fracturing of shale horizontal well is performed to study in detail the law of the initiation and growth of hydraulic fissures in Longmaxi Formation shale, the fracturing mechanics and the interaction between hydraulic fracture and natural fracture. On the basis of fracture mechanics and fluid mechanics theories, the mechanical model of hydraulic fracture initiation and expansion was established, and the corresponding fracture mechanics criterion was derived. Results indicate that: (1) The crack initiation mode can be divided into three categories, namely, tensile cracks started with shale, shear fractures started with natural fracture (bedding plane), and tensile cracks started with natural fracture. (2) During the extension of hydraulic fracture, the pump pressure decreases with the elongation of crack length and finally tends to a stable value, which is slightly bigger than the minimum horizontal principal stress. (3) According to whether the natural fracture is open, the interaction between hydraulic fracture and natural fracture can be divided into the following five types: penetration through the sheared natural fracture, penetration through the natural fractures directly, penetration through one end of the natural fracture, penetration through the natural fracture from two ends of the natural fracture synchronously, and penetration through the natural fracture from a weak surface. The research results offer strong technical support for horizontal well fracturing of shale gas.
关键词
龙马溪组页岩 /
水力压裂 /
裂缝起裂与扩展 /
物理模拟 /
泵压曲线 /
相互作用 /
天然裂缝
Key words
Longmaxi Formation shale /
hydraulic fracture /
crack initiation and propagation /
physical modelling /
pump pressure-time curve /
interaction /
natural fracture
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 金 成, 王 芳, 石 崇. 泥页岩浸水力学特性试验研究[J]. raybet体育在线
院报, 2017,34(9):126-130.
[2] 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.
[3] 陈 勉, 周 健, 金 衍, 等. 随机裂缝性储层压裂特征实验研究[J]. 石油学报, 2008, 29(3): 431-434.
[4] 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.
[5] 魏元龙.建南地区致密砂岩气藏压裂裂缝延伸规律研究[D]. 重庆:重庆大学, 2016.
[6] 王 磊, 杨春和, 郭印同,等. 基于室内水力压裂试验的水平井起裂模式研究 [J]. 岩石力学与工程学报, 2015, 34(增刊 2): 3624-3632.
[7] BEUGELSDIJK L J L, DE PATER C J, SATO K. Experimental Hydraulic Fracture Propagation in a Multi-fractured Medium[C]∥SPE Asia Pacific Conference on Integrated Modelling for Asset Management. Society of Petroleum Engineers. Yokohama, Japan, April 25-26, 2000, doi: 10.2118/59419-MS.
[8] BUNGER A P, JEFFREY R G, KEAR J, et al. Experimental Investigation of the Interaction among Closely Spaced Hydraulic Fractures[C]∥Proceedings of the 45th US Rock Mechanics/Geomechanics Symposium. American Rock Mechanics Association. San Francisco, California, June 26-29, 2011: ARMA-11-318.
[9] VAN KETTERIJ R B, DE PATER C J. Impact of Perforations on Hydraulic Fracture Tortuosity[J]. SPE Production & Facilities, 1999, 14(2): 117-130.
[10]程远方, 王桂华, 王瑞和. 水平井水力压裂增产技术中的岩石力学问题[J]. 岩石力学与工程学报, 2004, 23(14): 2463-2466.
[11]严成增, 郑 宏. 基于 FDEM-flow 的多孔水力压裂模拟 [J]. raybet体育在线
院报, 2016, 33(7):63-67.
[12]郭建春, 尹 建, 赵志红. 裂缝干扰下页岩储层压裂形成复杂裂缝可行性[J]. 岩石力学与工程学报, 2014, 33(8): 1589-1596.
[13]郭天魁, 张士诚, 刘卫来, 等. 页岩储层射孔水平井分段压裂的起裂压力[J]. 天然气工业, 2013, 33(12): 87-93.
[14]李 芷, 贾长贵, 杨春和, 等. 页岩水力压裂水力裂缝与层理面扩展规律研究[J]. 岩石力学与工程学报, 2015, 34(1): 12-20.
[15]张广清, 陈 勉. 定向射孔水力压裂复杂裂缝形态 [J]. 石油勘探与开发, 2009, 36(1) :103-107.
[16]赵金洲, 任 岚, 胡永全, 等. 裂缝性地层水力裂缝张性起裂压力分析[J]. 岩石力学与工程学报, 2013, 32(增刊 1): 2855-2861.
[17]HOSSAIN M M,RAHMAN M K,RAHMAN S S. Hydraulic Fracture Initiation and Propagation: Roles of Wellbore Trajectory,Perforation and Stress Regimes[J]. Journal of Petroleum Science and Engineering,2000,27(3):129-149.
[18]SABERHOSSEINI S E, AHANGARI K, MOHAMMADREZAEI H. Optimization of the Horizontal-well Multiple Hydraulic Fracturing Operation in a Low-permeability Carbonate Reservoir Using Fully Coupled XFEM Model[J]. International Journal of Rock Mechanics & Mining Sciences, 2019, 114: 33-45.
[19]RUEDA CORDERO J A, MEJIA SANCHEZ E C, ROEHL D, et al. Hydro-mechanical Modeling of Hydraulic Fracture Propagation and Its Interactions with Frictional Natural Fractures[J]. Computers and Geotechnics, 2019, 111: 290-300.
[20]NAGEL N B, SANCHEZ-NAGEL M A, ZHANG F, et al. Coupled Numerical Evaluations of the Geomechanical Interactions Between a Hydraulic Fracture Stimulation and a Natural Fracture System in Shale Formations[J]. Rock Mechanics & Rock Engineering, 2013, 46(3):581-609.
[21]侯振坤, 杨春和, 王 磊,等. 大尺寸真三轴页岩水平井水力压裂物理模拟试验与裂缝延伸规律分析[J]. 岩土力学, 2016, 37(2): 407-414.
[22]尹 建. 水平井分段压裂诱导应力场研究与应用[D]. 成都:西南石油大学, 2014.
[23]范天佑. 断裂理论基础[M]. 北京:科学出版社, 2003:73-112.
[24]IRWIN G R. Analysis of Stress and Strains Near the End of a Crack Traversing a Plate[J]. Journal of Applied Mechanics, 1957, 24:361-364.
[25]BLANTON T L. Propagation of Hydraulically and Dynamically Induced Fractures in Naturally Fractured Reservoirs[C]∥SPE Unconventional Gas Technology Symposium. Louisville, Kentucky: Society of Petroleum Engineers. May 18-21,1986: SPE-15261-MS.
[26]李世愚,和泰名,尹祥础.岩石断裂力学导论[M].合肥:中国科技大学出版社, 2010.
[27]吴德伦, 黄质宏, 赵明阶. 岩石力学[M]. 重庆:重庆大学出版社, 2002.
[28]程远方,常 鑫,孙元伟,等.基于断裂力学的页岩储层缝网延伸形态研究[J].天然气地球科学,2014,25(4):603-611.
[29]丁隧栋,孙利民.断裂力学[M].北京:机械工业出版社,1997:131-134.
[30]范天佑.断裂动力学原理与应用[M].北京:北京理工大学出版社,2006: 10-16.
基金
国家自然科学基金项目(51908225,51678171);中国博士后科学基金项目(2019M662918,2019M652899,2019M662917);广东省基础与应用基础研究基金区域联合基金-青年基金项目(2019A1515110836)
PDF(5241 KB)
