水平井定面射孔近井筒的破裂形态
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摘要
水平井定面射孔是致密油气藏体积压裂的一种新型射孔技术,但以往的研究较少考虑射孔对近井区域裂缝起裂位置、破裂形态的调控作用,并将定面射孔的各孔道空间位置均简化为平面,忽略了定面射孔角度参数对水平井破裂压力与近井筒裂缝形态的影响。为了弥补上述不足,建立了流固耦合形式的近井筒破裂力学模型,采用基于连续损伤力学的裂缝单元表征射孔局部三维破裂位置、形态变化,开发了耦合模型有限元数值求解程序以研究裂缝起裂与扩展规律,并运用长庆油气田现场水平井射孔完井参数,定量分析了射孔转角、射角参数变化对初始破裂压力、起裂位置的影响,对比了水平井定面射孔、螺旋射孔近井筒破裂形态的差异。研究结果表明:①射孔可调控水平井破裂压力及初始破裂位置,随射孔转角、射角改变,孔道破裂压力变化显著,初始破裂会产生于射孔—井筒界面、孔道中部等不同位置,定面射孔器材应控制射孔射角介于15°～30°;②定面射孔通过改变孔道射流方向,增加了孔道间应力干扰,能够有效降低水平井破裂压力2.0～3.5 MPa;③定面射孔能够引导和调控近井筒裂缝走向,形成垂直于水平井筒的初始破裂面、避免螺旋射孔导致的近井筒裂缝扭曲,提高了水平井近井筒裂缝系统的完善程度。结论认为,所建立的近井筒破裂力学模型可以模拟水平井射孔—近井筒动态破裂过程,模型计算结果与现场测试数据具有较好的一致性。
The in-plane perforation is a new type of well completion method for the stimulated reservoir volume(SRV) of tight oil and gas reservoirs. Previously, however, the regulatory effects of perforation on fracture initiation position and fracture geometry near the wellbore were less studied, the spatial position of each channel of in-plane perforation was simplified as a plane, and the effects of the angle parameters of in-plane perforation on the fracturing pressure of a horizontal well and the fracture geometry near the wellbore were neglected. In order to make up for these shortcomings, a near-wellbore fracture mechanics model in the form of hydro-mechanical coupling was established in this paper. Then, local 3 D fracture initiation position and geometric change of shots were characterized by using the fracture element based on continuous damage mechanics, and the finite-element numerical solving program of a coupling model was developed to investigate fracture initiation and propagation laws. Finally, the effects of perforation angle and departure angle on the initial fracturing pressure and fracture initiation position were analyzed quantitatively based on the actual perforation completion parameters of horizontal wells in the Changqing Oilfield. What's more, the fracture geometry near the wellbore of horizontal wells with in-plane perforation was compared with that with helical perforation. And the following research results were obtained. First, the fracturing pressure and fracture initiation position of the horizontal wells with controllable perforation vary with perforation angle and departure angle. The fracturing pressure of channel varies greatly, and fracture initiation occurs at different positions, e.g. the perforation—wellbore interface and the middle part of the channel. The in-plane perforator shall control the departure angle in the range of 15°–30°. Second, by changing the jet direction of channels, in-plane perforation increases the stress interference between the channels, so as to reduce the fracturing pressure of horizontal wells by 2.0–3.5 MPa. Third, the in-plane perforation can guide and control the fracture strike near the wellbore,so as to produce the initial fracture plane perpendicular to the wellbore of horizontal wells and avoid the distortion of near-wellbore fractures caused by helical perforation. In this way, the completion degree of the fracture the system near the wellbore of a horizontal well is improved. In conclusion, the near-wellbore fracture mechanics model established in this paper can simulate the perforation and near-wellbore dynamic fracture process of a horizontal well, and its calculation results are better accordant with the field test data.
The in-plane perforation is a new type of well completion method for the stimulated reservoir volume(SRV) of tight oil and gas reservoirs. Previously, however, the regulatory effects of perforation on fracture initiation position and fracture geometry near the wellbore were less studied, the spatial position of each channel of in-plane perforation was simplified as a plane, and the effects of the angle parameters of in-plane perforation on the fracturing pressure of a horizontal well and the fracture geometry near the wellbore were neglected. In order to make up for these shortcomings, a near-wellbore fracture mechanics model in the form of hydro-mechanical coupling was established in this paper. Then, local 3 D fracture initiation position and geometric change of shots were characterized by using the fracture element based on continuous damage mechanics, and the finite-element numerical solving program of a coupling model was developed to investigate fracture initiation and propagation laws. Finally, the effects of perforation angle and departure angle on the initial fracturing pressure and fracture initiation position were analyzed quantitatively based on the actual perforation completion parameters of horizontal wells in the Changqing Oilfield. What's more, the fracture geometry near the wellbore of horizontal wells with in-plane perforation was compared with that with helical perforation. And the following research results were obtained. First, the fracturing pressure and fracture initiation position of the horizontal wells with controllable perforation vary with perforation angle and departure angle. The fracturing pressure of channel varies greatly, and fracture initiation occurs at different positions, e.g. the perforation—wellbore interface and the middle part of the channel. The in-plane perforator shall control the departure angle in the range of 15°–30°. Second, by changing the jet direction of channels, in-plane perforation increases the stress interference between the channels, so as to reduce the fracturing pressure of horizontal wells by 2.0–3.5 MPa. Third, the in-plane perforation can guide and control the fracture strike near the wellbore,so as to produce the initial fracture plane perpendicular to the wellbore of horizontal wells and avoid the distortion of near-wellbore fractures caused by helical perforation. In this way, the completion degree of the fracture the system near the wellbore of a horizontal well is improved. In conclusion, the near-wellbore fracture mechanics model established in this paper can simulate the perforation and near-wellbore dynamic fracture process of a horizontal well, and its calculation results are better accordant with the field test data.
引文
[1]刘合,王峰,王毓才,高扬,成建龙.现代油气井射孔技术发展现状与展望[J].石油勘探与开发,2014,41(6):731-737.Liu He,Wang Feng,Wang Yucai,Gao Yang&Cheng Jianlong.Oil well perforation technology:Status and prospects[J].Petroleum Exploration and Development,2014,41(6):731-737.
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[3]李根生,黄中伟,牛继磊,张石兴.地应力及射孔参数对水力压裂影响的研究进展[J].石油大学学报(自然科学版),2005,29(4):136-142.Li Gensheng,Huang Zhongwei,Niu Jilei&Zhang Shixing.Research advance of the influence of geostress and perforation parameters on hydraulic fracturing[J].Journal of the University of Petroleum,China(Edition of Natural Science),2005,29(4):136-142.
[4]李海涛,王永清,李洪建,戈应文.压裂施工井的射孔优化设计方法[J].天然气工业,1998,18(2):53-56.Li Haitao,Wang Yongqing,Li Hongjian&Ge Yingwen.An optimum perforation design method for prefracturing wells[J].Natural Gas Industry,1998,18(2):53-56.
[5]陈华彬,唐凯,陈锋,陈建波,李奔驰,任国辉.水平井定向分簇射孔技术及其应用[J].天然气工业,2016,36(7):33-39.Chen Huabin,Tang Kai,Chen Feng,Chen Jianbo,Li Benchi&Ren Guohui.Oriented cluster perforating technology and its application in horizontal wells[J].Natural Gas Industry,2016,36(7):33-39.
[6]Abass HH,Hedayati S&Meadows DL.Nonplanar fracture propagation from a horizontal wellbore:Experimental study[J].SPEProduction&Facilities,1996,11(3):133-137.
[7]Van de Ketterij RG&de Pater CJ.Impact of perforations on hydraulic fracture tortuosity[J].SPE Production&Facilities,1999,14(2):131-138.
[8]胡永全,赵金洲,曾庆坤,徐树汉,谢慧华.计算射孔井水力压裂破裂压力的有限元方法[J].天然气工业,2003,23(2):58-59.Hu Yongquan,Zhao Jinzhou,Zeng Qingkun,Xu Shuhan&Xie Huihua.Finite element method to calculate fracture pressure of perforated well hydraulic[J].Natural Gas Industry,2003,23(2):58-59.
[9]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.Zhang Guangqing&Chen Mian.Complex fracture shapes in hydraulic fracturing with orientated perforations[J].Petroleum Exploration and Development,2009,36(1):103-107.
[10]Alekseenko OP,Potapenko DI,Cherny SG,Esipov DV,Kuranakov DS&Lapin VN.3-D Modeling of fracture initiation from perforated non-cemented wellbore[C]//SPE Hydraulic Fracturing Technology Conference,6-8 February 2012,The Woodlands,Texas,USA.DOI:https://doi.org/10.2118/151585-MS.
[11]朱海燕,邓金根,刘书杰,闫伟,陈峥嵘,文敏,等.定向射孔水力压裂起裂压力的预测模型[J].石油学报,2013,34(3):556-562.Zhu Haiyan,Deng Jingen,Liu Shujie,Yan Wei,Chen Zhengrong,Wen Min,et al.A prediction model for the hydraulic fracture initiation pressure in oriented perforation[J].Acta Petrolei Sinica,2013,34(3):556-562.
[12]陈小凡,唐潮,杜志敏,汤连东,魏嘉宝,马旭.基于有限体积方法的页岩气多段压裂水平井数值模拟[J].天然气工业,2018,38(12):77-86.Chen Xiaofan,Tang Chao,Du Zhimin,Tang Liandong,Wei Jiabao&Ma Xu.Numerical simulation on multi-stage fractured horizontal wells in shale gas reservoirs based on the finite volume method[J].Natural Gas Industry,2018,38(12):77-86.
[13]张然,李根生,朱海燕.水平多裂缝交错扩展及其诱导应力干扰研究[J].西南石油大学学报(自然科学版),2017,39(1):91-99.Zhang Ran,Li Gensheng&Zhu Haiyan.Dynamic propagation of multiple horizontal fractures and mutual interference between induced stresses[J].Journal of Southwest Petroleum University(Science&Technology Edition),2017,39(1):91-99.
[14]Shan Q,Jin Y,Chen M,Hou B,Zhang R&Wu Y.A new finite element method to predict the fracture initiation pressure[J].Journal of Natural Gas Science and Engineering,2017,43:58-68.
[15]Falser S,Mo W,Weng DW,Fu HF,Lu YJ,Ding YH,et al.Reducing breakdown pressure and fracture tortuosity by in-plane perforations and cyclic pressure ramping[C]//paper ARMA-2016-191 presented at the 50th U.S.Rock Mechanics/Geomechanics Symposium,26-29 June 2016,Houston,Texas,USA.
[16]Yuan L,Hou B,Shan Q,Chen M,Xiong Z&Zhang Y.Experimental investigation on hydraulic fracture initiation and geometry in the definite plane perforating technology of horizontal well[C]//SPE Asia Pacific Hydraulic Fracturing Conference,24-26 August2016,Beijing,China.DOI:https://doi.org/10.2118/181878-MS.
[17]刘合,兰中孝,王素玲,许建国,赵晨旭.水平井定面射孔条件下水力裂缝起裂机理[J].石油勘探与开发,2015,42(6):794-800.Liu He,Lan Zhongxiao,Wang Suling,Xu Jianguo&Zhao Chenxu.Hydraulic fracture initiation mechanism in the definite plane perforating technology of horizontal well[J].Petroleum Exploration and Development,2015,42(6):794-800.
[18]王素玲,隋旭,朱永超.定面射孔新工艺对水力裂缝扩展影响研究[J].岩土力学,2016,37(12):3393-3400.Wang Suling,Sui Xu&Zhu Yongchao.Effect of set surface perforating technology on hydraulic crack extension[J].Rock and Soil Mechanics,2016,37(12):3393-3400.
[19]张少程,张锋,周曌,张建峰,周虓彬.定射角定方位射孔新技术[J].测井技术,2012,36(1):68-72.Zhang Shaocheng,Zhang Feng,Zhou Zhao,Zhang Jianfeng&Zhou Xiaobin.On set shoot angle compass perforating technology[J].Well Logging Technology,2012,36(1):68-72.
[20]朱万成,魏晨慧,田军,杨天鸿,唐春安.岩石损伤过程中的热-流-力耦合模型及其应用初探[J].岩土力学,2009,30(12):3851-3857.Zhu Wancheng,Wei Chenhui,Tian Jun,Yang Tianhong&Tang Chun'an.Coupled thermal-hydraulic-mechanical model during rock damage and its preliminary application[J].Rock and Soil Mechanics,2009,30(12):3851-3857.
[21]Shojaei A,Dahi Taleghani A&Li GQ.A continuum damage failure model for hydraulic fracturing of porous rocks[J].International Journal of Plasticity,2014,59:199-212.
[22]Lewis RW&Schrefler BA.The finite element method in the deformation and consolidation of porous media[M].New York:John Wiley&Sons,1999.
[23]Sloan SW&Abbo AJ.Biot consolidation analysis with automatic time stepping and error control Part 1:Theory and implementation[J].International Journal for Numerical and Analytical Methods in Geomechanics,1999,23(6):493-529.
[24]Waters G&Weng XW.The impact of geomechanics and perforations on hydraulic fracture initiation and complexity in horizontal well completions[C]//SPE Annual Technical Conference and Exhibition,26-28 September 2016,Dubai,UAE.DOI:https://doi.org/10.2118/181684-MS.
[25]Hossain MM,Rahman MK&Rahman SS.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.
[2]Behrmann LA&Nolte KG.Perforating requirements for fracture stimulations[C]//SPE Formation Damage Control Conference,18-19 February 1998,Lafayette,Louisiana,USA.DOI:https://doi.org/10.2118/39453-MS.
[3]李根生,黄中伟,牛继磊,张石兴.地应力及射孔参数对水力压裂影响的研究进展[J].石油大学学报(自然科学版),2005,29(4):136-142.Li Gensheng,Huang Zhongwei,Niu Jilei&Zhang Shixing.Research advance of the influence of geostress and perforation parameters on hydraulic fracturing[J].Journal of the University of Petroleum,China(Edition of Natural Science),2005,29(4):136-142.
[4]李海涛,王永清,李洪建,戈应文.压裂施工井的射孔优化设计方法[J].天然气工业,1998,18(2):53-56.Li Haitao,Wang Yongqing,Li Hongjian&Ge Yingwen.An optimum perforation design method for prefracturing wells[J].Natural Gas Industry,1998,18(2):53-56.
[5]陈华彬,唐凯,陈锋,陈建波,李奔驰,任国辉.水平井定向分簇射孔技术及其应用[J].天然气工业,2016,36(7):33-39.Chen Huabin,Tang Kai,Chen Feng,Chen Jianbo,Li Benchi&Ren Guohui.Oriented cluster perforating technology and its application in horizontal wells[J].Natural Gas Industry,2016,36(7):33-39.
[6]Abass HH,Hedayati S&Meadows DL.Nonplanar fracture propagation from a horizontal wellbore:Experimental study[J].SPEProduction&Facilities,1996,11(3):133-137.
[7]Van de Ketterij RG&de Pater CJ.Impact of perforations on hydraulic fracture tortuosity[J].SPE Production&Facilities,1999,14(2):131-138.
[8]胡永全,赵金洲,曾庆坤,徐树汉,谢慧华.计算射孔井水力压裂破裂压力的有限元方法[J].天然气工业,2003,23(2):58-59.Hu Yongquan,Zhao Jinzhou,Zeng Qingkun,Xu Shuhan&Xie Huihua.Finite element method to calculate fracture pressure of perforated well hydraulic[J].Natural Gas Industry,2003,23(2):58-59.
[9]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.Zhang Guangqing&Chen Mian.Complex fracture shapes in hydraulic fracturing with orientated perforations[J].Petroleum Exploration and Development,2009,36(1):103-107.
[10]Alekseenko OP,Potapenko DI,Cherny SG,Esipov DV,Kuranakov DS&Lapin VN.3-D Modeling of fracture initiation from perforated non-cemented wellbore[C]//SPE Hydraulic Fracturing Technology Conference,6-8 February 2012,The Woodlands,Texas,USA.DOI:https://doi.org/10.2118/151585-MS.
[11]朱海燕,邓金根,刘书杰,闫伟,陈峥嵘,文敏,等.定向射孔水力压裂起裂压力的预测模型[J].石油学报,2013,34(3):556-562.Zhu Haiyan,Deng Jingen,Liu Shujie,Yan Wei,Chen Zhengrong,Wen Min,et al.A prediction model for the hydraulic fracture initiation pressure in oriented perforation[J].Acta Petrolei Sinica,2013,34(3):556-562.
[12]陈小凡,唐潮,杜志敏,汤连东,魏嘉宝,马旭.基于有限体积方法的页岩气多段压裂水平井数值模拟[J].天然气工业,2018,38(12):77-86.Chen Xiaofan,Tang Chao,Du Zhimin,Tang Liandong,Wei Jiabao&Ma Xu.Numerical simulation on multi-stage fractured horizontal wells in shale gas reservoirs based on the finite volume method[J].Natural Gas Industry,2018,38(12):77-86.
[13]张然,李根生,朱海燕.水平多裂缝交错扩展及其诱导应力干扰研究[J].西南石油大学学报(自然科学版),2017,39(1):91-99.Zhang Ran,Li Gensheng&Zhu Haiyan.Dynamic propagation of multiple horizontal fractures and mutual interference between induced stresses[J].Journal of Southwest Petroleum University(Science&Technology Edition),2017,39(1):91-99.
[14]Shan Q,Jin Y,Chen M,Hou B,Zhang R&Wu Y.A new finite element method to predict the fracture initiation pressure[J].Journal of Natural Gas Science and Engineering,2017,43:58-68.
[15]Falser S,Mo W,Weng DW,Fu HF,Lu YJ,Ding YH,et al.Reducing breakdown pressure and fracture tortuosity by in-plane perforations and cyclic pressure ramping[C]//paper ARMA-2016-191 presented at the 50th U.S.Rock Mechanics/Geomechanics Symposium,26-29 June 2016,Houston,Texas,USA.
[16]Yuan L,Hou B,Shan Q,Chen M,Xiong Z&Zhang Y.Experimental investigation on hydraulic fracture initiation and geometry in the definite plane perforating technology of horizontal well[C]//SPE Asia Pacific Hydraulic Fracturing Conference,24-26 August2016,Beijing,China.DOI:https://doi.org/10.2118/181878-MS.
[17]刘合,兰中孝,王素玲,许建国,赵晨旭.水平井定面射孔条件下水力裂缝起裂机理[J].石油勘探与开发,2015,42(6):794-800.Liu He,Lan Zhongxiao,Wang Suling,Xu Jianguo&Zhao Chenxu.Hydraulic fracture initiation mechanism in the definite plane perforating technology of horizontal well[J].Petroleum Exploration and Development,2015,42(6):794-800.
[18]王素玲,隋旭,朱永超.定面射孔新工艺对水力裂缝扩展影响研究[J].岩土力学,2016,37(12):3393-3400.Wang Suling,Sui Xu&Zhu Yongchao.Effect of set surface perforating technology on hydraulic crack extension[J].Rock and Soil Mechanics,2016,37(12):3393-3400.
[19]张少程,张锋,周曌,张建峰,周虓彬.定射角定方位射孔新技术[J].测井技术,2012,36(1):68-72.Zhang Shaocheng,Zhang Feng,Zhou Zhao,Zhang Jianfeng&Zhou Xiaobin.On set shoot angle compass perforating technology[J].Well Logging Technology,2012,36(1):68-72.
[20]朱万成,魏晨慧,田军,杨天鸿,唐春安.岩石损伤过程中的热-流-力耦合模型及其应用初探[J].岩土力学,2009,30(12):3851-3857.Zhu Wancheng,Wei Chenhui,Tian Jun,Yang Tianhong&Tang Chun'an.Coupled thermal-hydraulic-mechanical model during rock damage and its preliminary application[J].Rock and Soil Mechanics,2009,30(12):3851-3857.
[21]Shojaei A,Dahi Taleghani A&Li GQ.A continuum damage failure model for hydraulic fracturing of porous rocks[J].International Journal of Plasticity,2014,59:199-212.
[22]Lewis RW&Schrefler BA.The finite element method in the deformation and consolidation of porous media[M].New York:John Wiley&Sons,1999.
[23]Sloan SW&Abbo AJ.Biot consolidation analysis with automatic time stepping and error control Part 1:Theory and implementation[J].International Journal for Numerical and Analytical Methods in Geomechanics,1999,23(6):493-529.
[24]Waters G&Weng XW.The impact of geomechanics and perforations on hydraulic fracture initiation and complexity in horizontal well completions[C]//SPE Annual Technical Conference and Exhibition,26-28 September 2016,Dubai,UAE.DOI:https://doi.org/10.2118/181684-MS.
[25]Hossain MM,Rahman MK&Rahman SS.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.