天然裂缝对页岩气水平井压裂的影响及工艺调整

doi:10.3969/j.issn.1672-7703.2020.06.010

摘要/Abstract

摘要： 缝网压裂是页岩气“缝控储量”开发模式的具体体现，天然裂缝是影响水力裂缝扩展及压裂后效果的重要因素，国内外学者多采用数值模拟进行研究。基于矿场实践与数据统计分析，利用分类方法研究不同特征天然裂缝对压裂施工及效果的影响，开展了天然裂缝发育储层提高改造效果矿场探索与效果评价。研究结果表明：①前置高黏压裂液+ 低黏滑溜水携砂可解决细微天然裂缝发育储层加砂难度大、改造体积偏小、改造效果欠佳等难题；②大尺度天然裂缝发育储层压裂后裂缝复杂程度低、改造效果欠佳，与井筒大角度相交的大尺度天然裂缝是诱发套管变形、压裂井间干扰的潜在地质因素，暂堵转向压裂工艺对干扰裂缝扩展、提高改造效果存在一定不确定性；③后续相关研究应集中在大尺度天然裂缝与井筒平行情况下的压裂效果提高，以及与井筒大角度相交情况下的套管变形和压裂井间干扰防治。

关键词: 页岩气, 天然裂缝, 裂缝复杂程度, 储层改造体积, 井间干扰, 套管变形, 地质工程一体化

Abstract: Network fracturing is the practical implementation of the development mode of “fracture-controlled reserves” in shale gas wells. Natural fractures are an important factor affecting hydraulic fracture propagation and post-fracturing effects. In China and elsewhere numerical simulation is the normally adopted method for studying naturally occurring fractures. However, based on field practice and statistical data analysis, this paper uses the classification method to examine the influence of natural fractures with different characteristics on fracturing operations and post-fracturing effects and carries out field research and evaluation of improvements to reservoirs in which natural fractures are developed. The results show that: (1) For reservoirs with natural micro-fractures, problems such as difficulty of proppant adding, small stimulated reservoir volume, and poor simulation effect can be addressed by adopting “pad high-viscosity fracturing fluid + low-viscosity slick water carrying proppants”. (2) For reservoirs with large-scale natural fractures, the complexity of fractures following artificial fracturing is low and the fracturing effect is not favorable. Large-scale natural fractures intersecting with wellbores at large angles are the geological factor that may be responsible for casing deformation and frac hit. There are some uncertainties regarding the effects of temporary plugging diversion fracturing processes on fracture propagation interaction and improvements in stimulation effects. (3) Follow-up research should focus on improvement of fracturing effects when large-scale natural fractures are parallel to the wellbore, as well as prevention of casing deformation and frac-hit when large-scale natural fractures intersect with wellbores.

中图分类号:

周小金, 雍锐, 范宇, 曾波, 宋毅, 郭兴午, 周拿云, 段希宇, 朱仲义. 天然裂缝对页岩气水平井压裂的影响及工艺调整[J]. 中国石油勘探, 2020, 25(6): 94-104.

Zhou Xiaojin, Yong Rui, Fan Yu, Zeng Bo, Song Yi, Guo Xingwu, Zhou Nayun, Duan Xiyu, Zhu Zhongyi. Influence of natural fractures on fracturing of horizontal shale gas wells and process adjustment[J]. China Petroleum Exploration, 2020, 25(6): 94-104.

参考文献

[1] 马新华，谢军．川南地区页岩气勘探开发进展及发展前景[J]. 石油勘探与开发，2018,45(1):161-169. Ma Xinhua, Xie Jun. The progress and prospects of shale gas exploration and exploitation in southern Sichuan Basin, NW China[J]. Petroleum Exploration and Development, 2018,45(1): 161-169.
[2] 马新华．四川盆地天然气发展进入黄金时代[J]. 天然气工业，2017, 37(2):1-10. Ma Xinhua. A golden era for natural gas development in the Sichuan Basin[J]. Natural Gas Industry, 2017,37(2):1-10.
[3] 杨怀成，毛国扬，宋其仓，等．彭页HF-1 井页岩气藏大型压裂工艺技术[J]. 西南石油大学学报( 自然科学版)，2014,36(5):117-122. Yang Huaicheng, Mao Guoyang, Song Qicang, et al ．Large scale fracturing technology of well Pengye HF-1 shale gas[J]．Journal of Southwest Petroleum University (Science & Technology Edition), 2014,36(5):117-122．
[4] 肖佳林，李奎东，高东伟，等．涪陵焦石坝区块水平井组拉链压裂实践与认识[J]. 中国石油勘探，2018,23(2):51-58. Xiao Jialin, Li Kuidong, Gao Dongwei, et al ．Practice and cognition on zipper fracturing of horizontal well group in Jiaoshiba block, Fuling[J]. China Petroleum Exploration,2018,23(2):51-58.
[5] 谢军．长宁—威远国家级页岩气示范区建设实践与成效[J]. 天然气工业，2018,38(2):1-7. Xie Jun. Practices and achievements of the Changning-Weiyuan shale gas national demonstration project construction[J]. Natural Gas Industry, 2018,38(2):1-7.
[6] 谢军，鲜成钢，吴建发，等．长宁国家级页岩气示范区地质工程一体化最优化关键要素实践与认识[J]. 中国石油勘探，2019,24(2): 174-185. Xie Jun, Xian Chenggang, Wu Jianfa, et al ．Optimal key elements of geoengineering integration in Changning National Shale Gas Demonstration Zone[J]. China Petroleum Exploration, 2019, 24(2):174-185.
[7] 梁兴，徐进宾，刘成，等．昭通国家级页岩气示范区水平井地质工程一体化导向技术应用[J]. 中国石油勘探，2019,24(2):226-232. Liang Xing, Xu Jinbin, Liu Cheng, et al ．Geosteering technology based on geological and engineering integration for horizontal wells in Zhaotong National Shale Gas Demonstration Zone[J]. China Petroleum Exploration, 2019,24(2):226-232.
[8] 胡文瑞．地质工程一体化是实现复杂油气藏效益勘探开发的必由之路[J]. 中国石油勘探，2017,22(1):1-5. Hu Wenrui. Geology-engineering integration - a necessary way to realize profitable exploration and development of complex reservoirs[J]. China Petroleum Exploration, 2017,22(1):1-5.
[9] 廖仕孟，桑宇，宋毅，等．页岩气水平井套管变形影响段分段压裂工艺研究及矿场试验[J]. 天然气工业，2017,37(7):40-45. Liao Shimeng, Sang Yu, Song Yi, et al ．Research and field tests of staged fracturing technology for casing deformation section in horizontal shale gas wells [J]. Natural. Gas Industry, 2017,37(7):40-45.
[10] 孙焕泉，周德华，蔡勋育，等．中国石化页岩气发展现状与趋势[J]. 中国石油勘探，2020,25(2):14-26. Sun Huanquan, Zhou Dehua, Cai Xunyu, et al . Progress and prospect of shale gas development of Sinopec[J]. China Petroleum Exploration, 2020,25(2):14-26.
[11] 黄伟和，刘海．页岩气一体化开发钻井投资优化分析方法研究[J]. 中国石油勘探，2020,25(2):51-61. Huang Weihe, Liu Hai. Research on optimization analysis methods of drilling investment in integrated development of shale gas[J]. China Petroleum Exploration, 2020,25(2):51-61.
[12] 吴奇，胥云，王晓泉，等．非常规油气藏体积改造技术：内涵、优化设计与实现[J]. 石油勘探与开发，2012,39(3):352-358. Wu Qi, Xu Yun, Wang Xiaoquan, et al ．Volume fracturing technology of unconventional reservoirs: connotation, optimization design and implementation[J]. Petroleum Exploration and Development, 2012,39(3):352-358.
[13] 雷群，杨立峰，段瑶瑶，等．非常规油气“缝控储量”改造优化设计技术[J]. 石油勘探与开发，2018,45(4):719-726. Lei Qun, Yang Lifeng, Duan Yaoyao, et al . The“fracture-controlled reserves”based stimulation technology for unconventional oil and gas reservoirs[J]. Petroleum Exploration and Development, 2018,45(4):719-726.
[14] 宋毅，桑宇，曾波，等．四川盆地长宁区块龙马溪组页岩水平井压裂实践与认识[J]. 天然气工业，2017,37( 增刊1):133-137. Song Yi, Sang Yu, Zeng Bo, et al . Fracturing practice and understanding of horizontal shale wells in Longmaxi Formation, Changning Block, Sichuan Basin[J]. Natural Gas Industry, 2017,37(S1):133-137.
[15] 唐颖，邢云，李乐忠，等．页岩储层可压裂性影响因素及评价方法[J]. 地学前缘，2012,19(5):356-363. Tang Ying, Xing Yun, Li Lezhong, et al . Influence factors and evaluation methods of the gas shale fracability[J]. Earth Science Frontiers, 2012,19(5):356-363.
[16] 王志刚，孙健．涪陵页岩气田实验井组开发实践与认识[M]. 北京：中国石化出版社，2014. Wang Zhigang, Sun Jian. Practice and understanding of Fuling shale gas field experimental well group development[M]. Beijing: Sinopec Press, 2014.
[17] Wu K, Olson J E. Mechanics analysis of interaction between hydraulic and natural fractures in shale reservoirs[C]// Unconventional Resources Technology Conference. Denver: Society of Exploration Geophysicists, American Association of Petroleum Geologists, Society of Petroleum Engineers, 2014: 1824-1841.
[18] Blanton L T. Propagation of hydraulically and dynamically induced fractures in naturally fractured reservoirs [C]// Proceedings of SPE Gas Technology Symposium. Richardson: Society of Petroleum Engineers, 1986:18-21.
[19] 陈朝伟，石林，项德贵．长宁—威远页岩气示范区套管变形机理及对策[J]. 天然气工业，2016,36(11):70-75. Chen Zhaowei, Shi Lin, Xiang Degui. Mechanism of casing deformation in the Changning-Weiyuan national shale gas project demonstration area and counter measures[J]. Natural Gas Industry, 2016,36(11):70-75.
[20] 张华礼，陈朝伟，石林，等．流体通道形成机理及在四川页岩气套管变形分析中的应用[J]. 钻采工艺，2018,41(4):8-11. Zhang Huali, Chen Zhaowei, Shi Lin, et al . Formation mechanism of fluid channel and its application in casing deformation analysis of shale gas in Sichuan province[J]. Drilling ＆ Production Technology, 2018,41(4):8-11.
[21] Ingraffea A R, Wells M T, Santoro R L, et al . Assessment and risk analysis of casing and cement impairment in oil and gas wells in Pennsylvania, 2000-2012[J]. Proceedings of the National Academy of Sciences, 2014,111(30):10955-10960.
[22] Jackson K, Palisch T, Lehman L. Completion optimization with Ceramics provides step changes in horizontal performance for the 2nd Bone Spring Formation - a southeastern new Mexico case history[C]. Amsterdam: Society of Petroleum Engineers, 2014.
[23] Adams N J, Mitchell R F, Eustes A W, et al . A causation investigation for observed casing failures occurring during fracturing operations[C]. USA: Society of Petroleum Engineers, 2017.
[24] Liu Z, Samuel R, Gonzales A, et al . Analysis of casing fatigue failure during multistage fracturing operations[C]. Abu Dhabi: Society of Petroleum Engineers, 2018.
[25] Barreda D, Shahri M P, Wagner R, et al . Impact of cyclic pressure loading on well integrity in multi-stage hydraulic fracturing[C]. Canada: Unconventional Resources Technology Conference, 2018.