Response characteristics and mechanism for fracturing interference of adjacent wells of shale gas wells: A case study in the Fuling shale gas field
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摘要:
涪陵页岩气田是我国探明储量最大的非常规页岩气田, 储层以页岩为主, 具有低孔低渗、非均质性强等特点。自2018年率先在国内部署开发调整井并实施水力压裂, 面临着由于压力场变化导致周围老井压力异常变化, 从而影响老井正常生产等问题, 给气田采收率的提升带来了不确定的因素。从已产生影响的一次井网老井生产情况来看, 邻井压裂影响干扰特征呈现多类型、多特征、多结果、多主控因素的特点, 而目前还没有统一的邻井压裂干扰响应特征描述方法和机理解释。以涪陵页岩气田为例, 在大量文献调研的基础上, 基于一次井网整体有效动用程度, 开展了页岩气井邻井压裂干扰响应特征及机理探讨。研究表明: (1)页岩气邻井干扰按照对母井技术可采储量的影响结果分为正面、无、负面干扰3种类型, 造成3种干扰类型的差异主要与子母井空间井距、穿行层位、采出程度、地层压力、应力差异等因素相关; (2)初步明确了产生邻井压裂干扰的机理是子井和母井裂缝沟通程度及两者人工缝网重叠程度不同; (3)根据干扰带来的不同结果需采取合理的井距设计, 压裂施工前采取母井关井恢复压力至稳定状态、子井压裂施工期间采取远场封堵转向压裂技术等方式规避负面影响。研究结果为制定合理的压裂防干扰措施提供了理论支撑, 对行业具有良好的指导意义。
Abstract:Objective Regarding conventional gas resources, research on the fracturing interference of adjacent wells has focused mainly on interference during the production process; the interference of adjacent wells is usually avoided by determining the rational spacing between wells, and the radius of influence is the key to determining a reasonable well spacing. The fracturing interference of shale gas adjacent wells involves various types, phenomena, results and control factors; however, there is no generally accepted description method or mechanism for studying the response characteristics of the fracturing interference of adjacent wells.
Methods The Fuling shale gas field is taken as an example to discuss the response characteristics and mechanism of the fracturing interference of adjacent wells in shale gas.
Results According to the impact on the recoverable reserves of parent wells, the fracturing interference of shale gas adjacent wells can be divided into three types: positive interference, noninterference and negative interference. The three types of interference are mainly related to the spacing of the child and parent wells, crossing layers, recovery percentage, formation pressure, stress difference and other factors. The closer the spacing and crossing layers between wells are, the greater the recovery degree of the parent wells or the lower the formation pressure is, the greater the difference between both sides of the stress of the child well becomes, and the greater the fracturing interference becomes. On the basis of the different results caused by fracturing interference, to avoid negative effects, shale gas development requires the formulation of reasonable well spacings, the shuttling of parent wells to restore the pressure until it stabilizes before fracturing, and the use of diverters during fracturing of new child wells. The generation mechanisms of fracturing interference are the degree of fracture and the overlap of artificial fracturing networks between child wells and parent wells. The ideal situation is that the fracturing network edge of the child wells just reaches the fracturing network edge of the older parent wells, which has a positive effect on increasing production; however, the noninterference type does not occur when the child wells' SRV is insufficient, nor does the negative interference type occur when the fracturing networks are connected between the child wells and parent wells.
Conclusion The research results provide theoretical support for formulating reasonable fracturing interference prevention measures and have good guiding significance in industry.
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表 1 焦石坝区块子井压裂期间母井受干扰响应特征汇总
Table 1. Summary of the disturbance response characteristics of parent wells during the fracturing of subwells in the Jiaoshiba block
影响情况 压力响应特征 压裂后邻井表现形式 ΔP/MPa 波动段 正面影响 0.2~2.5,平均 < 0.9 平稳阶梯抬升 产气量增加 无明显影响 < 0.2 缓慢平稳抬升 产气量无变化 负面影响 >2.5 尖峰状、击穿状抬升或变化 产气量降低、产水增加 -
[1] 郭建春, 路千里, 何佑伟. 页岩气压裂的几个关键问题与探索[J]. 天然气工业, 2022, 42(8): 148-161. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG202208010.htmGUO J C, LU Q L, HE Y W. Key issues and explorations in shale gas fracturing[J]. Natural Gas Industry, 2022, 42(8): 148-161. (in Chinese with English abstract) https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG202208010.htm [2] 王志刚, 孙健. 涪陵页岩气田试验井组开发实践与认识[M]. 北京: 石油工业出版社, 2014.WANG Z G, SUN J. Practice and understanding of the development of test wells in Fuling shale gas field[M]. Beijing: Petroleum Industry Press, 2014. (in Chinese) [3] ROBERT L J, WATTENBARGER A. Gas reservoir engineering[M]. WANG Y P, GUO W K, PANG Y N, et al. Translated. Beijing: Petroleum Industry Press, 2007. [4] 李继庆, 黄灿, 沈金才, 等. 一种判别页岩气流动状态的新方法[J]. 特种油气藏, 2016, 23(1): 100-103. https://www.cnki.com.cn/Article/CJFDTOTAL-TZCZ201601022.htmLI J Q, HUANG C, SHEN J C, et al. A new method to distinguish shale gas flow states[J]. Special Oil & Gas Reservoirs, 2016, 23(1): 100-103. (in Chinese with English abstract) https://www.cnki.com.cn/Article/CJFDTOTAL-TZCZ201601022.htm [5] 孙赞东, 贾承造, 李相方, 等. 非常规油气勘探与开发[M]. 北京: 石油工业出版社, 2011: 72-76.SUN Z D, JIA C Z, LI X F, et al. Unconventional oil and gas exploration and development[M]. Beijing: Petroleum Industry Press, 2011: 72-76. (in Chinese) [6] 王川, 董田, 蒋恕, 等. 中扬子地区上奥陶统-下志留统五峰组-龙马溪组页岩纵向非均质性及主控因素[J]. 地质科技通报, 2022, 41(3): 108-121. doi: 10.19509/j.cnki.dzkq.2021.0053WANG C, DONG T, JIANG S, et al. Vertical heterogeneity and the main controlling factors of the Upper Ordovician-Lower Silurian Wufeng-Longmaxi shales in the Middle Yangtze region[J]. Bulletin of Geological Science and Technology, 2022, 41(3): 108-121. (in Chinese with English abstract) doi: 10.19509/j.cnki.dzkq.2021.0053 [7] 王必金, 包汉勇, 刘皓天, 等. 川东红星地区吴家坪组富有机质页岩特征与发育控制因素[J]. 地质科技通报, 2023, 42(5): 70-81. doi: 10.19509/j.cnki.dzkq.tb20230149WANG B J, BAO H Y, LIU H T, et al. Characteristics and controlling factors of the organic-rich shale in the Wujiaping Formation of the Hongxing area, eastern Sichuan Basin[J]. Bulletin of Geological Science and Technology, 2023, 42(5): 70-81. (in Chinese with English abstract) doi: 10.19509/j.cnki.dzkq.tb20230149 [8] 刘方圆. 定量分析邻井压裂对页岩气井生产的影响[J]. 长江大学学报(自然科学版), 2018, 15(11): 60-63. https://www.cnki.com.cn/Article/CJFDTOTAL-CJDL201811013.htmLIU F Y. Quantitative analysis of the impact of adjacent well fracturing on shale gas well production[J]. Journal of Changjiang University (Natural Science Edition), 2018, 15(11): 60-63. (in Chinese with English abstract) https://www.cnki.com.cn/Article/CJFDTOTAL-CJDL201811013.htm [9] 沈金才, 刘尧文. 涪陵焦石坝区块页岩气井产量递减典型曲线应用研究[J]. 石油钻探技术, 2016, 44(4): 88-95. https://www.cnki.com.cn/Article/CJFDTOTAL-SYZT201604018.htmSHEN J C, LIU Y W. Application study on typical production decline curves of shale gas wells in the Jiaoshiba Block, Fuling[J]. Petroleum Drilling Techniques, 2016, 44(4): 88-95. (in Chinese with English abstract) https://www.cnki.com.cn/Article/CJFDTOTAL-SYZT201604018.htm [10] 孙贺东. 油气井现代产量递减分析方法及应用[M]. 北京: 石油工业出版社, 2013.SUN H D. Advanced production decline analysis and application[M]. Beijing: Petroleum Industry Press, 2013. (in Chinese) [11] 阿普斯J J. 生产动态分析理论与实践[M]. 雷群, 万玉金, 孙贺东, 等, 译. 北京: 石油工业出版社, 2008.ARPS J J. Production dynamic analysis theory and practice[M]. LEI Q, WAN Y J, SUN H D, et al, translated. Beijing: Petroleum Industry Press, 2008. (in Chinese) [12] 沈金才. 涪陵焦石坝区块页岩气井动态合理配产技术[J]. 石油钻探技术, 2018, 46(1): 103-109. https://www.cnki.com.cn/Article/CJFDTOTAL-SYZT201801017.htmSHEN J C. The technique of rational and dynamic production allocation of shale gas well in Jiaoshiba block, Fuling area[J]. Petroleum Drilling Techniques, 2018, 46(1): 103-109. (in Chinese with English abstract) https://www.cnki.com.cn/Article/CJFDTOTAL-SYZT201801017.htm [13] 沈金才, 董长新, 常振. 涪陵页岩气田气井生产阶段划分及动态特征描述[J]. 天然气勘探与开发, 2021, 44(1): 111-117. https://www.cnki.com.cn/Article/CJFDTOTAL-TRKT202101016.htmSHEN J C, DONG C X, CHANG Z. Classifying and describing the production stage and dynamic characteristics of gas wells, Fuling shale gas field[J]. Natural Gas Exploration and Development, 2021, 44(1): 111-117. (in Chinese with English abstract) https://www.cnki.com.cn/Article/CJFDTOTAL-TRKT202101016.htm [14] BAZAN L W, LARKIN S D, LATTIBEAUDIERE, M G, et al. Improving production in the Eagle Ford Shale with fracture modeling, increased conductivity and optimized stage and cluster spacing along the horizontal wellbore[J]. SPE, 2010, 138425. [15] BOWKER K A. Barnett Shale gas production, Fort Worth Basin: Issues and discussion[J]. AAPG Bulletin, 2007, 91(4): 523-533. [16] SARDINHA C M, PETR C, LEHMANN J, et al. Determining interwell connectivity and reservoir complexity through fracturing pressure hits and production interference analysis[J]. SPE, 2014, 171628. [17] GUINDON L. Determining interwell connectivity and reservoir complexity through fracturing pressure hits and production-interference analysis[J]. Journal of Canadian Petroleum Technology, 2015, 54(2): 88-91. [18] DANESHY A, AU-YEUNG J, THOMPSON T, et al. Fracture shadowing: A direct method for determination of the reach and propagation pattern of hydraulic fractures in horizontal wells[J]. SPE, 2012, 151980. [19] WATERS G A, DEAN B K, DOWNIE R C, et al. Simultaneous hydraulic fracturing of adjacent horizontal wells in the Woodford Shale[J]. SPE, 2009, 119635. [20] MUKHERJEE H, POE B, HEIDT H, et al. Effect of pressure depletion on fracture-geometry evolution and production performance[J]. SPE, 2000, 30481. [21] CURTIS J B. Fractured shale-gas systems[J]. AAPG Bulletin, 2002, 86(11): 1921-1938. [22] VULGAMORE T B, CLAWSON T D, POPE C D, et al. Applying hydraulic fracture diagnostics to optimize stimulations in the Woodford Shale[J]. SPE, 2007, 110029.